阅读说明：本技术 基于纳米光刻的荧光光盘信息读取方法及装置 (Method and device for reading information of fluorescent optical disk based on nano photoetching ) 是由 王中阳 张力 于 2019-01-18 设计创作，主要内容包括：本发明提供超分辨数字存储信息的读取方法,包括：令波长为λ-(1)的实心激发光束与波长为λ-(2)的空心损耗光束的焦平面在空间上重合；将重合后的光束聚焦作用于光盘物理存储介质的荧光记录层；所述实心光束激发所述荧光记录层产生中心波长为λ-(3)的荧光,所述空心光束抑制所述荧光记录层产生荧光；其中,λ-(2)位于所述荧光记录层的荧光峰的后沿,且λ-(1)＜λ-(3)＜λ-(2)；探测所述荧光记录层的各信息记录点处的荧光信号；根据各所述荧光信号的强弱判断对应的信息记录点是否完成了荧光信息的写入,并根据判断结果还原出所述光盘物理存储介质中的数据存储信息。本发明有利于缩小信息记录点的尺寸与间距,实现光盘的超高密度信息稳定、长久存储,以及对超高密度光盘存储信息的有效、高速提取。(The invention provides a reading method of super-resolution digital storage information, which comprises the following steps: let the wavelength be lambda 1 Solid excitation beam and wavelength of lambda 2 The focal planes of the hollow loss beams are spatially coincident; focusing the superposed light beam on a fluorescent recording layer of the optical disk physical storage medium; the solid light beam excites the fluorescent recording layer to generate light with a central wavelength of lambda 3 The hollow light beam inhibits the fluorescence of the fluorescence recording layer; wherein λ is 2 At the trailing edge of the fluorescence peak of the fluorescent recording layer, and λ 1 ＜λ 3 ＜λ 2 (ii) a Detecting a fluorescent signal at each information recording point of the fluorescent recording layer; and judging whether the corresponding information recording points finish writing the fluorescent information according to the intensity of each fluorescent signal, and restoring the data storage information in the physical storage medium of the optical disk according to the judgment result. The invention is beneficial to reducing the information memoryThe size and the distance of the recording points realize the stable and long-term storage of the ultrahigh-density information of the optical disc and the effective and high-speed extraction of the information stored in the ultrahigh-density optical disc.)

1. A reading method of super-resolution digital storage information is characterized by comprising the following steps:

let the wavelength be lambda₁Solid excitation beam and wavelength of lambda₂The focal planes of the hollow loss beams are spatially coincident;

focusing the superposed light beam on a fluorescent recording layer of the optical disk physical storage medium;

the solid light beam excites the fluorescent recording layer to generate light with a central wavelength of lambda₃The hollow light beam inhibits the fluorescence of the fluorescence recording layer; wherein λ is₂At the trailing edge of the fluorescence peak of the fluorescent recording layer, and λ₁＜λ₃＜λ₂；

Detecting a fluorescent signal at each information recording point of the fluorescent recording layer;

and judging whether the corresponding information recording points finish writing the fluorescent information according to the intensity of each fluorescent signal, and restoring the data storage information in the physical storage medium of the optical disk according to the judgment result.

2. The method according to claim 1, wherein determining whether the writing of the fluorescent information is previously completed for the corresponding information recording point according to the intensity of each fluorescent signal, and recovering the data storage information in the physical storage medium of the optical disc according to the determination result comprises:

if the intensity of the fluorescent signal is lower than a first threshold value, the corresponding information recording point is considered to finish the writing of the fluorescent information previously, and then digital storage information 1 is generated;

if the intensity of the fluorescence signal is higher than a second threshold value, the corresponding information recording point is considered not to be written with the fluorescence information previously, and then digital storage information 0 is generated;

and sequencing the digital storage information according to the sequence of the information recording points to obtain final data storage information.

3. The method of claim 2, further comprising: and realizing the multi-layer storage information reading of the optical disc physical storage medium by adopting a confocal chromatography type reading mode.

4. The method of claim 1, wherein the superposed light beams are focused on different fluorescence recording layers by adjusting the position of the sample to realize multi-layer storage information reading of the fluorescence information.

5. The method of claim 1, wherein the laser wavelengths of the solid excitation beam and the hollow loss beam avoid absorption peaks of an absorption modulation material of the physical storage medium of the optical disc.

6. The method of claim 1, wherein the beam intensity of the solid excitation beam conforms to a gaussian intensity distribution; the beam intensity of the hollow loss beam follows an annular intensity distribution and the central intensity tends to zero.

7. An optical disc information reading apparatus based on nanolithography, for implementing the reading method of the super-resolution digital storage information according to any one of claims 1 to 6; the optical disc information reading apparatus includes: the device comprises an excitation laser, a loss laser, a first coupling lens, a second coupling lens, a third coupling lens, a first filtering piece, a second filtering piece, a first collimating lens, a second collimating lens, a vortex phase plate, a first dichroic mirror, a second dichroic mirror, a beam splitter, a filter, a detector and a high power objective; wherein the content of the first and second substances,

the loss laser, the first coupling lens, the first filtering piece, the first collimating lens, the vortex phase plate and the first dichroic mirror are sequentially arranged along a light path; the loss light beam is emitted from the loss laser, is focused by the first coupling lens and is filtered by the first filtering piece, the filtered divergent light beam is collimated and expanded by the first collimating lens and then passes through the vortex phase plate to generate a laser beam with the phase distributed from 0 to pi, the laser beam is reflected by the first dichroic mirror to enter the high power objective lens and is focused to form a hollow light beam with the central intensity approaching zero;

the excitation laser, the second coupling lens, the second filtering piece, the second collimating lens and the second dichroic mirror are sequentially distributed along a light path; the excitation light beam is emitted from the excitation laser, is focused by the second coupling lens, is filtered by the second filtering piece, and the filtered divergent light beam is collimated and expanded by the second collimating lens, is reflected by the second dichroic mirror to enter the high-power objective lens, and is focused to form a solid light spot with the size of a diffraction limit level;

the solid light beam and the focal plane of the hollow light beam are overlapped in space and act on the optical disk physical storage medium to read the writing information on the fluorescent recording layer of the optical disk physical storage medium, and the fluorescent signal is collected by the high-power objective lens;

the beam splitter, the filter plate and the detector are sequentially distributed along a light path; and after the fluorescence signal is split by the beam splitter, the fluorescence signal sequentially passes through the filter and the third coupling lens and is collected by the detector, and the detector compares and decodes the fluorescence intensity to obtain the writing information.

8. The reading apparatus according to claim 7, wherein the position of the high power objective lens is adjusted so that the overlapped solid beam and the hollow beam are focused on different fluorescent recording layers, thereby reading the writing information of each fluorescent recording layer.

9. The reading apparatus according to claim 7, wherein the first filter member comprises: micron-scale small holes or single mode fibers; the second filter member includes: micron-scale apertures or single mode fibers.

10. An optical disc information read-write device based on nanolithography is characterized by comprising: the nanolithography based optical disc information reading apparatus according to any one of claims 7 to 9.

Technical Field

The invention relates to the technical field of optics, in particular to a method and a device for reading optical disc information based on nano lithography.

Background

With the development of technologies such as gene sequencing and brain activity reading, not only a large amount of data is generated, but also higher requirements are put forward on how to effectively, stably and accurately store the data. Based on the above background, the optical disc storage technology has advantages of energy saving, long storage life, good safety, easy processing, etc., and thus, the optical disc storage technology well complies with the requirements of the times. For optical disc technology, the limitation of storage capacity has seriously hindered the development of optical disc technology.

In order to increase the capacity of an optical disc, the conventional technical route is to reduce the size of a recording spot. With the successful development of short wavelength laser diodes (GaN blue-green lasers), blu-ray discs are becoming the mainstream storage mode in the optical disc market. In the early CD, the recording laser wavelength was 780nm, the numerical aperture was 0.45, the track pitch was 1.6 μm, and the single-layer storage capacity was only 650 MB; later DVD optical disk, recording laser wavelength is 650nm, numerical aperture is 0.6, track pitch is 0.74 μm, single-layer storage capacity is 4.7 GB; the current blue-ray disc has the recording laser wavelength of 405nm, the numerical aperture of 0.85 and the track spacing of 0.32 mu m, the track spacing is only half of that of a red-ray DVD disc (0.74 mu m), the single-layer storage capacity is up to 25GB, and meanwhile, the blue-ray disc achieves the multi-layer writing effect by utilizing different reflectivities, thereby realizing 12-layer 300GB blue-ray disc storage.

In order to further break through the limitation of the storage capacity of the optical disc, some methods for increasing the storage capacity have been proposed by researchers.

The 2009 australian sensitivity research team utilized the differences in the response of gold nanowires of different aspect ratios to laser light of different wavelengths and polarization directions to achieve three-layer five-dimensional (x, y, z, λ and polarization) optical information storage within 10 μm thickness (Nature,2009,459(7245): 410-.

In 2011, a S.W Hell research team provides a novel microscopic technology RESOLFT (reversible structural optical 'fluorescence' transition between two states) for super-resolution optical storage reading and writing, and a high-density optical storage experiment (Nature,2011,478,204 and 208) with a point spacing of 250nm is realized by using the photocuring and photoswitch characteristics of green fluorescent protein (rseFP) and a super-resolution writing and reading method.

The suspicion research team in australia in 2012 combines the photo-polymerization and super-resolution stimulated emission loss technical principle, and utilizes a 1, 5-bis (p-dimethylaminociocinnimide) cyclopentanone (BDCC) material system to realize the photoetching channel width of 9nm and the channel spacing of 52nm (Nature Communications,2013,4.6: 2061). The mechanism of the photo-polymerization photoetching can be used for writing information of the optical disk at high density, and accordingly an international patent (appl.No. 15/039,368; PCT No. PCT/AU2013/001378) is applied by a sensitive research team.

Disclosure of Invention

In view of the above-mentioned shortcomings of the prior art, the present invention provides a method and an apparatus for reading information from an optical disc based on nanolithography, which is used to reduce the size and pitch of information recording dots and realize the stable and long-term storage of ultra-high density information in the optical disc.

To achieve the above and other related objects, the present invention provides a method for reading super-resolution digitally stored information, comprising: let the wavelength be lambda₁Solid excitation beam and wavelength of lambda₂The focal planes of the hollow loss beams are spatially coincident; focusing the superposed light beam on a fluorescent recording layer of the optical disk physical storage medium; the solid light beam excites the fluorescent recording layer to generate light with a central wavelength of lambda₃The hollow light beam inhibits the fluorescence of the fluorescence recording layer; wherein λ is₂At the trailing edge of the fluorescence peak of the fluorescent recording layer, and λ₁＜λ₃＜λ₂(ii) a Detecting a fluorescent signal at each information recording point of the fluorescent recording layer; judging whether the corresponding information recording point completes the writing of the fluorescence information according to the intensity of each fluorescence signal, and further judging whether the corresponding information recording point completes the writing of the fluorescence information according to the judgment resultAnd generating the data storage information in the physical storage medium of the optical disc.

In an embodiment of the present invention, determining whether writing of the fluorescent information in the corresponding information recording point is completed previously according to the intensity of each fluorescent signal, and restoring the data storage information in the physical storage medium of the optical disc according to the determination result, specifically includes: if the intensity of the fluorescent signal is lower than a first threshold value, the corresponding information recording point is considered to finish the writing of the fluorescent information previously, and then digital storage information 1 is generated; if the intensity of the fluorescence signal is higher than a second threshold value, the corresponding information recording point is considered not to be written with the fluorescence information previously, and then digital storage information 0 is generated; and sequencing the digital storage information according to the sequence of the information recording points to obtain final data storage information.

In an embodiment of the present invention, the reading method of the digital storage information adopts a confocal tomography reading method, which has high longitudinal resolution, and can realize reading of fluorescence information of different depths of a multilayer optical disc and reading of multilayer storage information of the optical disc.

In an embodiment of the present invention, the position of the sample is adjusted, and the superposed focal spots of the light beam are applied to different fluorescence recording layers, so as to read the multi-layer stored information of the fluorescence information.

In an embodiment of the present invention, the laser wavelengths of the solid excitation beam and the hollow loss beam are kept away from the absorption peak of the absorption modulation material of the physical storage medium of the optical disc.

In an embodiment of the present invention, the beam intensity of the solid excitation beam conforms to a gaussian intensity distribution; the beam intensity of the hollow loss beam follows an annular intensity distribution and the central intensity tends to zero.

In order to achieve the above objects and other related objects, the present invention provides an optical disc information reading apparatus based on nanolithography, for implementing the reading method of super-resolution digital storage information; the optical disc information reading apparatus includes: the device comprises an excitation laser, a loss laser, a first coupling lens, a second coupling lens, a third coupling lens, a first filtering piece, a second filtering piece, a first collimating lens, a second collimating lens, a vortex phase plate, a first dichroic mirror, a second dichroic mirror, a beam splitter, a filter, a detector and a high power objective; the loss laser, the first coupling lens, the first filtering piece, the first collimating lens, the vortex phase plate and the first dichroic mirror are sequentially arranged along a light path; the loss light beam is emitted from the loss laser, is focused by the first coupling lens and is filtered by the first filtering piece, the filtered divergent light beam is collimated and expanded by the first collimating lens and then passes through the vortex phase plate to generate a laser beam with the phase distributed from 0 to pi, the laser beam is reflected by the first dichroic mirror to enter the high power objective lens and is focused to form a hollow light beam with the central intensity approaching zero; the excitation laser, the second coupling lens, the second filtering piece, the second collimating lens and the second dichroic mirror are sequentially distributed along a light path; the excitation light beam is emitted from the excitation laser, is focused by the second coupling lens, is filtered by the second filtering piece, and the filtered divergent light beam is collimated and expanded by the second collimating lens, is reflected by the second dichroic mirror to enter the high-power objective lens, and is focused to form a solid light spot with the size of a diffraction limit level; the solid light beam and the focal plane of the hollow light beam are overlapped in space and act on the optical disk physical storage medium to read the writing information on the fluorescent recording layer of the optical disk physical storage medium, and the fluorescent signal is collected by the high-power objective lens; the beam splitter, the filter plate and the detector are sequentially distributed along a light path; and after the fluorescence signal is split by the beam splitter, the fluorescence signal sequentially passes through the filter and the third coupling lens and is collected by the detector, and the detector compares and decodes the fluorescence intensity to obtain the writing information.

In an embodiment of the present invention, the position of the high power objective lens is adjusted to focus the overlapped solid beam and hollow beam on different fluorescent recording layers, so as to read the writing information of each fluorescent recording layer.

In an embodiment of the present invention, the first filter includes: micron-scale small holes or single mode fibers; the second filter member includes: micron-scale apertures or single mode fibers.

In order to achieve the above and other related objects, the present invention provides an optical disc information reading/writing device based on nanolithography, including the optical disc information reading device based on nanolithography.

As described above, the method and apparatus for reading information from an optical disc based on nanolithography of the present invention can greatly reduce the size and spacing of information recording dots, and can record multi-layer information, thereby effectively increasing the storage density and storage capacity of the optical disc, and realizing stable and long-term storage of large data volume and effective and high-speed extraction of information stored in an ultra-high density optical disc.

Drawings

Fig. 1 is a flowchart illustrating a method for writing information on an optical disc based on nanolithography according to an embodiment of the present invention.

FIG. 2 is a schematic diagram of a principle of dual beam lithography information writing in an embodiment of the present invention.

FIG. 3 is a graph showing an absorption spectrum of an absorption modulation material according to an embodiment of the present invention.

FIG. 4 is a schematic diagram of a single beam lithography information writing scheme according to an embodiment of the present invention.

FIG. 5 is a schematic diagram of a single beam multi-layer lithography information writing scheme in an embodiment of the present invention.

FIG. 6 is a schematic diagram of a dual beam multi-layer lithography information writing scheme according to an embodiment of the present invention.

Fig. 7 is a flowchart illustrating an optical disc information reading method based on nanolithography according to an embodiment of the present invention.

FIG. 8 is a schematic view of the super-resolution reading principle of multi-layer lithography information according to an embodiment of the present invention.

Fig. 9 is a schematic structural diagram of a dual-beam writing optical disc reading/writing apparatus according to an embodiment of the present invention.

FIG. 10 is a block diagram of an embodiment of a single-beam optical disc writing/reading apparatus.

Detailed Description

The embodiments of the present invention are described below with reference to specific embodiments, and other advantages and effects of the present invention will be easily understood by those skilled in the art from the disclosure of the present specification. The invention is capable of other and different embodiments and of being practiced or of being carried out in various ways, and its several details are capable of modification in various respects, all without departing from the spirit and scope of the present invention. It is to be noted that the features in the following embodiments and examples may be combined with each other without conflict.

It should be noted that the drawings provided in the following embodiments are only for illustrating the basic idea of the present invention, and the components related to the present invention are only shown in the drawings rather than drawn according to the number, shape and size of the components in actual implementation, and the type, quantity and proportion of the components in actual implementation may be changed freely, and the layout of the components may be more complicated.

As shown in fig. 1, a schematic flowchart of an embodiment of a method for writing information into an optical disc based on nanolithography according to the present invention includes the following steps:

s11: compressing the focal spot size of the solid writing beam;

the solid writing light beam adopts visible, ultraviolet and deep ultraviolet continuous laser or pulse laser with wave band between visible light and ultraviolet light.

There are at least two implementations of step S11:

the method comprises the steps of forming a solid writing light beam and a hollow suppression light beam with different wavelengths respectively; the beam intensity of the solid writing beam conforms to Gaussian intensity distribution; the beam intensity of the hollow suppression beam conforms to the annular intensity distribution and the central intensity tends to be zero; making focal planes of the solid writing light beam and the hollow suppression light beam coincide on the space; irradiating the superposed light beams to a physical storage medium of an optical disk, wherein the hollow suppression light beams suppress peripheral light spots of the solid writing light beams so as to compress the focal spot size of the solid writing light beams;

and secondly, reducing the wavelength of the solid writing light beam and/or increasing the numerical aperture of the objective lens.

Optionally, the solid writing beam in the first or second mode is a pulse beam, so as to implement two-photon writing.

S12: reading digital storage information to be stored in the optical disc;

the digital storage information is also used as writing control information; the writing control information comprises binary numbers corresponding to the information recording points one by one; the "0" and "1" digits of each binary digit are used to indicate whether or not writing of fluorescent information is performed at the corresponding information recording spot, respectively, for example, the "0" digit is used to indicate that writing is not performed at the corresponding information recording spot, and the "1" digit is used to indicate that writing is performed at the corresponding information recording spot.

S13: and controlling the compressed focal spot to write the fluorescent information at each information recording point of a fluorescent recording layer of the physical storage medium of the optical disk according to the writing control information.

In detail, the fluorescent recording layer, i.e. the optical disc recording layer, is made of a fluorescent material, and writing of fluorescent information is performed at each information recording point of the optical disc physical storage medium, i.e. the compressed solid writing beam is controlled to perform a nanolithography process at the corresponding information recording point, i.e. writing of the fluorescent material is performed.

A detailed embodiment of the nanolithography based optical disc information writing method is set forth below by way of example.

Fig. 2 shows a structure of an optical disc physical storage medium, including:

1) the protective layer 101 enables the optical disc to withstand frequent use, fingerprints, scratches and dirt, and ensures the storage quality and data security of the optical disc;

2) an absorption modulation layer 102, the layer of material having absorption modulation characteristics, the absorption spectrum of which is characterized as shown in fig. 3, the layer thickness being typically less than 500nm, the material of the absorption modulation layer including but not limited to: diarylethenes, fulgides and azides;

3) a fluorescent recording layer 103 for recording fluorescent information, which is characterized by being stably preserved, having high fluorescence efficiency and stability, and being optically writable, and mainly composed of a commonly used fluorescent material such as 8-hydroxyquinoline (AIQ-3) and a curing agent, but not limited thereto;

4) the base layer 104 is used to protect the storage structure of the physical medium of the optical disc.

With reference to the physical storage structure of the optical disc, the following explains the principle of writing information by dual-beam lithography based on the first method:

the solid writing beam 105 and the hollow inhibiting beam 106 act on the absorption modulation layer 102 simultaneously, and the hollow inhibiting beam 106 inhibits the peripheral beam of the solid writing beam 105 from transmitting through the absorption modulation layer 102 by the absorption modulation characteristic, so that the size of the writing spot transmitted through the absorption modulation layer 102 is further compressed, and as shown in 107, the beam 110 compressed by the absorption modulation layer 102 acts on the fluorescent recording layer 103 for information writing. During writing, the writing control information at the information recording point 1 is read, so as to determine whether to write the fluorescent information, i.e. whether to perform the lithography writing. If the writing control information is "1" digit, writing is performed at the information recording spot 1, and if the writing control information is "0", writing is not performed at the information recording spot 1. After the information writing at the information recording spot 1 is completed, the light beam 110 is made to act on the next information recording spot 2 to perform the writing of the fluorescent information, and so on until the information recording process on the fluorescent recording layer is completed, thereby improving the information storage dimension and the storage capacity of the optical disc.

Here, a description is given to the above-described dual-beam lithography information writing method in some cases: the method using a beam of wavelengths lambda₁And a beam of wavelength lambda₂The absorption modulation layer of the optical disk physical storage medium is prevented from being irradiated by continuous laser, super-resolution nano-lithography writing is realized through the absorption modulation characteristics of the absorption modulation material, and focal spots of writing light beams penetrating through the absorption modulation layer are greatly compressed, so that nano-lithography information recording exceeding diffraction limit light spots is realized. The method is carried outThe application characteristics are as follows: wavelength of λ₁Irradiating the absorption modulation material with an intensity such that the material has a wavelength λ₁The writing light is transparent; wavelength lambda₂By simultaneously irradiating the material with an intensity such that the material is at a wavelength λ₂The light beam of (2) produces strong absorption; focal planes of the two beams of light are overlapped in space, the writing light beam is a solid light beam, the light intensity accords with Gaussian intensity distribution, and the function of recording information is achieved; the inhibition light beam is a hollow light beam, the light intensity accords with the annular intensity distribution, the central intensity is approximately zero (the central intensity can be generated by a vortex phase plate or a spatial light modulator and the like), and the effect of inhibiting peripheral light spots of the writing light beam from transmitting through the absorption modulation layer is achieved; the writing light beam compressed by the absorption modulation layer acts on the fluorescent recording layer. The irradiation time and the beam intensity of the writing beam and the inhibiting beam are respectively controlled, and the accurate control of the etching depth and the etching width of the fluorescent recording layer can be realized. In the double-beam nano photoetching information writing method, the writing beam can be blue light or ultraviolet short-wavelength continuous laser.

Fig. 4 shows a structure of an optical disc physical storage medium, including:

1) the protective layer 201 enables the optical disc to withstand frequent use, fingerprints, scratches and dirt, and ensures the storage quality and data security of the optical disc;

2) a fluorescent recording layer 202 for recording fluorescent information, which is characterized by being stably preserved, having high fluorescence efficiency and stability, and being optically writable, and mainly composed of a commonly used fluorescent material such as 8-hydroxyquinoline (AIQ-3) and a curing agent, but not limited thereto;

3) the base layer 104 is used to protect the storage structure of the physical medium of the optical disc.

In conjunction with the physical storage structure of the optical disc, the following explains the principle of writing information by single beam lithography based on the second method:

the compressed diffraction-limited focused spot 204 is obtained by focusing with a shorter wavelength writing laser beam (which may be semiconductor laser light with 405nm or shorter wavelength output, or 355 nm and 266 nm solid laser output, or 248 nm, 193 nm and 157 nm excimer laser output, etc.) and a high numerical aperture objective lens, which acts on the fluorescent recording layer 202 for information recording. During writing, the writing control information at the information recording point 207 is read, so as to determine whether to write the fluorescent information, i.e. whether to perform the lithography writing. If the writing control information is "1" number, writing is performed at the information recording spot 1, and if the writing control information is "0", writing is not performed at the information recording spot 207. After the information writing at the information recording spot 207 is completed, the light beam 204 is made to act on the next information recording spot 2 to perform the writing of the fluorescent information, and so on until the information recording process on the fluorescent recording layer is completed, thereby improving the information storage dimension and the storage capacity of the optical disc.

Fig. 5 shows a structure of an optical disc physical storage medium, including:

1) a protective layer 301 that allows the disc to withstand frequent use, fingerprints, scratches and dirt, thereby ensuring the storage quality and data security of the disc;

2)302 is a fluorescent recording layer 1 for performing fluorescent information recording of information of a first layer, which has a thickness of more than 1/2 wavelengths, is characterized by stable preservation, high fluorescence efficiency and stability, and optical writing, and is mainly composed of a commonly used fluorescent material such as 8-hydroxyquinoline (AIQ-3) and a curing agent, but not limited thereto;

3)303 is an intermediate transition layer 1, the thickness of which is less than 1/2 wavelengths, and is arranged between the fluorescence recording layer 1 and the fluorescence recording layer 2 for protecting information crosstalk between the fluorescence recording layers, and common materials include organic materials such as PVA;

4)304 is a fluorescence recording layer 2, used for recording the fluorescence information of the first layer information, the thickness of the layer is larger than 1/2 wavelengths, the layer material can be the same as the fluorescence recording layer material 1, or the fluorescence material with other fluorescence wavelengths can be selected, and the crosstalk of signals can be effectively avoided by adopting multi-wavelength fluorescence for storage;

5)305 is an intermediate transition layer 2, the thickness of which is less than 1/2 nm, between the fluorescent recording layer 1 and the fluorescent recording layer 2, for protecting the information crosstalk between the fluorescent recording layers, and the common materials include organic materials such as PVA;

6)306 is a fluorescence recording layer 3, which is used for recording the fluorescence information of the first layer information, the thickness of the layer is larger than 1/2 wavelengths, the layer material can be the same as the fluorescence recording layer materials 1 and 2, or the fluorescence materials with other fluorescence wavelengths can be selected, and the crosstalk of signals can be effectively improved by adopting multi-wavelength fluorescence for storage;

7)307 is an intermediate transition layer 3, the thickness of which is less than 1/2 wavelengths, and is arranged between the fluorescence recording layer 3 and the substrate for protecting the information crosstalk between the fluorescence recording layer and the substrate, and common materials include organic materials such as PVA;

8) the base layer 308 is used to protect the storage structure of the physical medium of the optical disc.

In combination with the physical storage structure of the optical disc, the following describes an improved method of writing information based on the single-beam lithography method in the second mode:

the fluorescent information is written at an information recording spot (e.g., 312) on the fluorescent recording layer 1 by focusing 302 a light beam focused by the objective lens 309 onto the fluorescent recording layer 1. When in writing, the writing control information at the information recording point is read to judge whether to write the fluorescent information, namely whether to write by photoetching. If the writing control information is '1' digit, writing is performed at the information recording point, and if the writing control information is '0', writing is not performed at the information recording point. After the information writing at the information recording point is completed, the light beam is made to act on the next information recording point of the current layer to write the fluorescent information, and so on until the information recording process on the fluorescent recording layer 1 is completed.

By moving the upper and lower positions of the objective lens 309 or adjusting the laser divergence of the focused beam, the focal depth of the beam is adjusted (process 310), so that the focused beam acts on the fluorescent recording layer 2 at 304, and when writing and writing of fluorescent information are performed at an information recording point (e.g., 313) on the fluorescent recording layer 2, writing control information at the information recording point is read, thereby determining whether writing of fluorescent information, that is, whether lithography writing is performed. If the writing control information is '1' digit, writing is performed at the information recording point, and if the writing control information is '0', writing is not performed at the information recording point. After the information writing at the information recording point is completed, the light beam is made to act on the next information recording point of the current layer to write the fluorescent information, and so on until the information recording process on the fluorescent recording layer 2 is completed.

The writing of the fluorescent information is performed at the information recording point (e.g., 314) on the fluorescent recording layer 3 by moving the up-down position of the objective lens 309 or adjusting the laser divergence of the focused light beam to adjust the focal depth of the light beam (process 311) so that the focused light beam acts 306 on the fluorescent recording layer 3. If the writing control information is '1' digit, writing is performed at the information recording point, and if the writing control information is '0', writing is not performed at the information recording point. After the information writing at the information recording point is completed, the light beam is made to act on the next information recording point of the current layer to write the fluorescent information, and so on until the information recording process on the fluorescent recording layer 3 is completed.

In order to avoid the crosstalk problem of multilayer fluorescent signals, the solid writing light beam adopts a pulse light beam, the two-photon characteristic of the material is utilized, and the signal crosstalk problem in the writing process is avoided through the threshold characteristic of the two-photon process. Meanwhile, a compressed diffraction-limited focusing spot is obtained by using a shorter-wavelength writing laser beam (semiconductor laser with 405nm or shorter wavelength output, or 355 nm and 266 nm solid laser output, or 248 nm, 193 nm and 157 nm excimer laser output and the like) and a focusing mode of a high-numerical-aperture objective lens.

Fig. 6 shows a structure of an optical disc physical storage medium, including:

1) a protective layer 401 that allows the disc to withstand frequent use, fingerprints, scratches and dirt, thereby ensuring the storage quality and data security of the disc;

2)402 is an absorption modulation layer 1, the layer material has absorption modulation characteristics, the absorption spectrum is shown in fig. 3, the layer thickness is generally less than 500nm, the layer compresses the writing pulse beam gaussian linearity, the compressed beam acts on the fluorescent recording layer 1 for the fluorescent information writing process, the absorption modulation layer material includes: diarylethenes, fulgides and azides, but not limited to these;

3)403 is a fluorescent recording layer 1 for performing fluorescent information recording of information of a first layer, which has a thickness of more than 1/2 wavelengths, is characterized by stable preservation, high fluorescence efficiency and stability, and optical writing, and is mainly composed of a commonly used fluorescent material such as 8-hydroxyquinoline (AIQ-3) and a curing agent, but not limited thereto;

4)404 is an absorption modulation layer 2, which has absorption modulation characteristics, the absorption spectrum of which is shown in fig. 3, the layer thickness is less than 500nm, the layer compresses the writing pulse beam in gaussian linearity, the compressed beam acts on the fluorescent recording layer 2 for fluorescent writing process, the absorption modulation layer material includes, but is not limited to, diarylethenes, fulgides and azides;

5)405 is a fluorescence recording layer 2, used for recording the fluorescence information of the second layer information, the thickness of the layer is greater than 1/2 wavelengths, the material of the layer can be the same as that of the fluorescence recording layer 1, or the fluorescence material with other fluorescence wavelengths can be selected, and the crosstalk of signals can be effectively improved by adopting multi-wavelength fluorescence for storage;

6)406 is an absorption modulation layer 3, which has absorption modulation characteristics, the absorption spectrum of which is shown in fig. 3, the layer thickness is less than 500nm, the layer compresses the write pulse beam gaussian-linearly, the compressed beam acts on the fluorescent recording layer 3 for the fluorescent information writing process, the absorption modulation layer material includes: diarylethenes, fulgides and azides, but not limited to these;

7)407 is a fluorescence recording layer 3, which is used for recording the fluorescence information of the third layer of information, the thickness of the layer is greater than 1/2 wavelengths, the material of the layer can be the same as that of the fluorescence recording layers 1 and 2, or fluorescent materials with other fluorescence wavelengths can be selected, and crosstalk of signals can be effectively improved by adopting multi-wavelength fluorescence for storage;

8)408 is an intermediate transition layer, the thickness of which is less than 1/2 wavelengths, and is arranged between the fluorescence recording layer 3 and the substrate for protecting the information crosstalk between the fluorescence recording layer and the substrate, and the common materials include organic materials such as PVA;

8) the base layer 409 is used to protect the physical medium storage structure of the optical disc.

With reference to the physical storage structure of the optical disc, the following describes an improved method of the dual-beam lithography information writing method based on the first mode:

the solid write beam 411 and the hollow inhibit beam 412 are focused by the objective lens 410 to act on the 402 absorption modulation layer 1, and then act on the absorption modulation layer 1, and the laser beam 413 passing through the absorption modulation layer is focused to act on the 403 fluorescent recording layer 1, and the fluorescent information writing process, i.e. whether the photoetching writing is performed, is performed at the information recording point (e.g. 414) on the fluorescent recording layer 1. If the writing control information is '1' digit, writing is performed at the information recording point, and if the writing control information is '0', writing is not performed at the information recording point. After the information writing at the information recording point is completed, the light beam is made to act on the next information recording point of the current layer to write the fluorescent information, and so on until the information recording process on the fluorescent recording layer 1 is completed.

The intensity and divergence of the solid write beam 411 and the hollow suppression beam 412 and the position of the objective lens are adjusted (process 415) such that the laser beam transmitted through the absorption modulation layer is focused 404 on the absorption modulation layer 2 and the laser beam transmitted through the absorption modulation layer is focused 405 on the fluorescent recording layer 2, and a fluorescent information writing process, i.e., whether or not a photolithography writing process is performed, is performed at an information recording spot (e.g., 419) on the fluorescent recording layer 2. If the writing control information is '1' digit, writing is performed at the information recording point, and if the writing control information is '0', writing is not performed at the information recording point. After the information writing at the information recording point is completed, the light beam is made to act on the next information recording point of the current layer to write the fluorescent information, and so on until the information recording process on the fluorescent recording layer 2 is completed.

The intensity and divergence of the solid write beam 411 and the hollow suppression beam 412 and the position of the objective lens are adjusted (process 420) such that the laser beam transmitted through the absorption modulation layer is focused 406 on the absorption modulation layer 3 and the laser beam transmitted through the absorption modulation layer is focused 407 on the fluorescent recording layer 3, and a fluorescent information writing process, i.e., whether or not a photolithography writing process is performed, is performed at an information recording spot (e.g., 424) on the fluorescent recording layer 3. If the writing control information is '1' digit, writing is performed at the information recording point, and if the writing control information is '0', writing is not performed at the information recording point. After the information writing at the information recording point is completed, the light beam is made to act on the next information recording point of the current layer to write the fluorescent information, and so on until the information recording process on the fluorescent recording layer 3 is completed.

In order to avoid the crosstalk problem of the multilayer fluorescent signal, the solid writing beam 411 is a pulse beam, and the signal crosstalk problem in the writing process is avoided by utilizing the two-photon characteristic of the material and the threshold characteristic of the two-photon process.

Using a wavelength of λ₁The pulse laser beam is used as writing laser, the beam is solid, the light intensity accords with Gaussian intensity distribution, and the function of writing information is achieved; wavelength of λ₂The continuous light beam is used as a restraining light beam, the light beam is a hollow light beam, the light intensity accords with annular intensity distribution, the central intensity is approximately zero (the central intensity can be generated by a vortex phase plate or a spatial light modulator and the like), and the effect of restraining peripheral light spots of the writing light beam from transmitting through the absorption modulation layer is achieved; the absorption modulation material has absorption modulation characteristics and two-photon absorption characteristics, and the absorption modulation material has two states, i.e. a state 1 and a state 2, as shown in FIG. 3, corresponding to a "CF state" and an "OF state", respectively, wherein the "CF state" corresponds to a wavelength λ₂Has strong light absorption to the wavelength lambda₁Light absorption of (2) is weak; "OF state" for wavelength λ₂Has weak light absorption and has a wavelength of lambda₁The light absorption of (2) is strong. Wavelength of λ₁The pulse laser irradiates an absorption modulation material with certain power density, and the material generates a two-photon absorption process and is converted from a state 1 to a state 2; wavelength of λ₂Is irradiated with a light beam that causes the material to switch from state 2 to state 1, and the absorption modulating material in state 1 has a wavelength λ₂The laser absorption rate of (2) is low. Therefore, when the focal planes of the two light beams are spatially coincident while being focused on the absorption modulation layer, the absorption modulation material is etched back due to the two-photon absorption characteristicThe writing light beam generates a two-photon absorption process, and the inhibition light beam promotes the absorption of the absorption modulation layer on the writing light beam, so that the peripheral light beam of the writing light beam is inhibited from penetrating through the absorption modulation layer, the Gaussian line type compression process of the writing light beam penetrating through the absorption modulation layer is realized, the writing light beam exceeding the diffraction limit is obtained, and the writing light beam acts on the fluorescent recording layer to realize the fluorescent nano photoetching information writing.

In the method, for other fluorescent recording layers, due to the threshold characteristic of two-photon absorption, the unfocused region does not reach the two-photon absorption power density of the absorption modulation material, and the writing light beam is not absorbed so as to be transmitted; suppression of the beam due to state 1 versus wavelength λ₂The laser absorption rate of the optical recording layer is low, and the optical recording layer can smoothly penetrate through other fluorescent recording layers, so that the compression process of writing light beams is realized only on the light beam focusing layer, the photoetching information is written, and the problem of writing information crosstalk between different fluorescent recording layers during information writing is avoided.

As shown in fig. 7, the effective storage information reading of the ultra-high density optical disc is realized by the following super-resolution fluorescence reading method based on the optical disc writing data completed by the aforementioned writing method, which includes the following steps:

s71: let the wavelength be lambda₁Solid excitation beam and wavelength of lambda₂The focal planes of the hollow loss beams are spatially coincident;

the beam intensity of the solid excitation beam conforms to Gaussian intensity distribution; the beam intensity of the hollow loss beam follows an annular intensity distribution and the central intensity tends to zero.

S72: the superposed light beam is focused and acted on a fluorescent recording layer of the optical disk physical storage medium.

S73: the solid light beam excites the fluorescent recording layer to generate light with a central wavelength of lambda₃The hollow light beam inhibits the fluorescence of the fluorescence recording layer;

λ₂at the trailing edge of the fluorescence peak of the fluorescent recording layer, and λ₁＜λ₃＜λ₂(ii) a The solid excitation beam and the laser wavelength of the hollow loss beam are avoidedThe absorption peak of the absorption modulation material of the optical disc physical storage medium can avoid the influence of the absorption modulation layer on the reading of the fluorescence writing information.

S74: detecting a fluorescent signal at each information recording spot of the fluorescent recording layer.

S75: and judging whether the corresponding information recording point completes the writing of the fluorescent information in advance according to the strength of each fluorescent signal, and restoring the data storage information in the physical storage medium of the optical disk according to the judgment result.

Specifically, if the intensity of the fluorescent signal is lower than the first threshold, it is determined that the corresponding information recording point has previously completed writing of the fluorescent information, and then digital storage information "1" is generated; if the intensity of the fluorescence signal is higher than a second threshold value, the corresponding information recording point is considered not to be written with the fluorescence information previously, and then digital storage information 0 is generated; and sequencing the digital storage information according to the sequence of the information recording points to obtain final data storage information.

Taking the three-layered storage medium structure shown in FIG. 8 as an example, the implementation of steps S71-S75 will be described in detail below.

Fig. 8 shows a structure of an optical disc physical storage medium, where 501 is a protective layer, 502 is a fluorescent recording layer 1, 504 is a fluorescent recording layer 2, 506 is a fluorescent recording layer 3, 503, 505, 507 are intermediate transition layers, and 508 is a base layer.

1) For the structure of the multi-layer optical disc storage medium after writing, laser beams 510 and 511 are focused by an objective lens 509 to act on 502 the fluorescent recording layer 1, and the fluorescent signal of the layer is read;

2) the laser beam 510 is a solid beam, the light intensity conforms to Gaussian intensity distribution, so that the fluorescent material generates fluorescence, the laser beam 511 is a hollow beam, the light intensity conforms to annular intensity distribution, the central intensity is approximately zero (the central intensity can be generated by a vortex phase plate or a spatial light modulator and the like), the effect of inhibiting the fluorescent material from generating fluorescence is achieved, the effect of erasing the fluorescence is achieved, and the super-resolution reading of the fluorescence is achieved;

3) performing super-resolution reading process of fluorescence signal at information recording point (such as 514) on the fluorescence recording layer 1, indicating that the point is stored with information when the corresponding fluorescence intensity is low, and decoding the recorded information of the point to be '1'; when the corresponding fluorescence intensity is higher, the point is not stored with information, and the recorded information of the point is decoded to be 0; completing the information reading process at the information recording point, moving the optical disk storage medium structure, and enabling the light beam to act on the next information recording point of the fluorescent recording layer 1 to read the fluorescent information, and repeating the above steps until the information reading process on the fluorescent recording layer 1 is completed;

4) moving the objective lens position (process 512), so that the light beams 510 and 511 are focused on 504 the fluorescent recording layer 2, performing a super-resolution reading process of a fluorescent signal at an information recording point (e.g. 515) on the fluorescent recording layer 2, indicating that information is stored at the point when the corresponding fluorescent intensity is lower, and decoding that the recorded information of the point is '1'; when the corresponding fluorescence intensity is higher, the point is not stored with information, and the recorded information of the point is decoded to be 0; completing the information reading process at the information recording point, moving the optical disk storage medium structure, and enabling the light beam to act on the next information recording point of the fluorescent recording layer 2 to read the fluorescent information, and repeating the above steps until the information reading process on the fluorescent recording layer 2 is completed;

5) moving the objective lens position (process 513) to focus the light beams 510 and 511 onto the fluorescent recording layer 3, performing a super-resolution reading process of the fluorescent signal at an information recording point (e.g. 516) on the fluorescent recording layer 3, indicating that the information is stored at the point when the corresponding fluorescent intensity is lower, and decoding that the recorded information at the point is "1"; when the corresponding fluorescence intensity is higher, the point is not stored with information, and the recorded information of the point is decoded to be 0; and finishing the information reading process at the information recording point, moving the optical disk storage medium structure, and enabling the light beam to act on the next information recording point of the fluorescent recording layer 3 to read the fluorescent information, and repeating the steps until the information reading process on the fluorescent recording layer 3 is finished.

It is worth noting that for fluorescent materials, the wavelength is λ₁The laser excites the fluorescent material to generate a central wavelength of lambda₃Fluorescence (lambda) of (A)₁＜λ₂)，Wavelength of λ₂The laser can inhibit the material from generating fluorescence (lambda)₂At the back edge of the fluorescence peak of the fluorescent material, lambda₂＞λ₃) Thus, the wavelength is λ₁Solid beam and wavelength of lambda₂The hollow light beam acts on the fluorescence recording layer at the same time with certain light intensity, the light intensity of the solid light beam accords with Gaussian intensity distribution, and the fluorescent material is excited to generate fluorescence; the light intensity of the hollow light beam accords with the annular intensity distribution, the central intensity is approximately zero (the light intensity can be generated by a vortex phase plate or a spatial light modulator and the like), the fluorescence generated by the material is inhibited, the fluorescence erasing effect is achieved, and the super-resolution fluorescence information reading is realized. The fluorescent material has a central fluorescence wavelength of lambda₃The wavelength of the excitation light is selected to be lambda₁And the wavelength of the lost light is lambda₂(λ₁＜λ₃＜λ₂) After the excitation light beam and the loss light beam are focused by the objective lens, focal planes of the two light beams are overlapped in space and jointly focused to act on the fluorescent recording layer, and super-resolution fluorescent information reading is carried out on the stored information at the fixed position of the fluorescent recording layer; and regarding a certain information recording point, if the detected fluorescent signal is weak, the point is considered to complete the fluorescent writing process, and the data storage information is recorded as '1', otherwise, if the fluorescent signal is strong, the point is considered not to have the fluorescent writing process previously, and the data storage information is recorded as '0'.

Preferably, the method for reading the digitally stored information of the present embodiment adopts a "confocal tomography" reading method. By "confocal tomography" is meant reading in a confocal manner, collecting the signals layer by layer, so that point-to-point reading can be achieved, for example: when reading the signal of the second layer, light also hits the first layer, but the signal of the first layer is not collected. The confocal chromatography type reading method has high longitudinal resolution, and can realize reading of fluorescence information of different depths of a multilayer optical disc, thereby realizing reading of multilayer storage information of the optical disc.

Corresponding to the above optical disc information writing method and reading method based on nanolithography, the present invention provides the following optical disc writing and reading device based on the method, comprising: a double beam writing optical disc reading and writing device and a single beam writing optical disc reading and writing device.

Dual beam writing optical disc reading and writing apparatus as shown in figure 9,

1) the writing light beam is emitted from the laser 601, after being modulated by the acousto-optic modulator 605, the laser light beam is focused by the lens 607, and the corresponding μm-level aperture 609 is selected according to the focal length and NA of the lens 607 to filter the light beam, or a single mode fiber can be selected to replace the aperture 609;

2) inhibiting light beams from emitting from a laser 602, after being modulated by an acousto-optic modulator 606, focusing the laser light beams by a lens 608, and selecting a corresponding micron-level aperture 610 to filter the light beams according to the focal length and NA of the lens 608, or selecting a single-mode optical fiber to replace the aperture 610;

3) the divergent light beam after the space filtering of the writing light beam is collimated and expanded by the collimating lens 611, the collimated light beam is reflected by the dichroic mirror 629 and then enters the high-power objective 621, and the objective focuses to form a solid light spot with the size of the diffraction limit dimension;

4) the divergent light beam after the suppression light beam is spatially filtered is collimated and expanded by the collimating lens 612, the collimated light beam passes through the vortex phase plate 613 to generate a laser beam with a phase from 0 to pi, the laser beam is reflected by the dichroic mirror 630 and then enters the high power objective 621, and the hollow light beam with the central intensity approximate to zero is formed after the light beam is focused by the objective;

5) by taking the focal plane of the hollow light beam as a reference, adjusting the divergence of the writing light beam by adjusting the front and rear positions of the lens 611, adjusting the dichroic mirror 629, adjusting the incident angle of the writing light beam to make the writing light beam spatially coincide with the focal plane of the inhibiting light beam, acting on the physical storage medium structure 626 of the optical disc, performing the process of writing the lithography information on the fluorescent recording layer 1, and controlling the irradiation time and the light beam intensity of the writing light beam and the inhibiting light beam respectively by the acousto-optic modulators 605 and 606 to precisely control the writing of the fluorescence of the recording layer 1;

6) adjusting the objective lens position or sample position 631 to focus the writing beam on different fluorescent recording layers, respectively, thereby implementing a multi-layer information storage process of the optical disc;

7) for writing an optical disc, a loss light beam is emitted from a laser 603, is focused by a lens 614, and is filtered by selecting a corresponding μm-level pinhole 618 according to the focal length and NA of the lens 615, or a single-mode fiber can be selected to replace the pinhole 618;

8) laser beams are emitted from a laser 604 and focused by a lens 615, and the corresponding mu m-level pinhole 617 is selected according to the focal length and NA of the lens 615 to filter the beams, or single-mode optical fibers can be selected to replace the pinhole 617;

9) the diverging light beam after the excitation light beam is subjected to spatial filtering is collimated and expanded by the collimating lens 619, the collimated light beam is reflected by the dichroic mirror 628 and then enters the high-power objective lens 621, and the objective lens focuses to form a solid light spot with the size of the diffraction limit dimension;

10) the diverging light beam after spatial filtering of the loss light beam is collimated and expanded by the collimating lens 618, the collimated light beam passes through the vortex phase plate 620 to generate a laser beam with a phase from 0 to pi, the laser beam is reflected by the dichroic mirror 627 and then enters the high power objective 621, and the hollow light beam with the central intensity approximate to zero is formed after focusing by the objective;

11) the hollow light beam focal plane is taken as a reference, the divergence of the writing light beam is adjusted by adjusting the front and rear positions of the lens 619, the dichroic mirror 628 is adjusted, the incident angle of the writing light beam is adjusted, the writing light beam and the focal plane of the inhibition light beam are overlapped in space, the light beam acts on the physical storage medium structure 626 of the optical disc at the same time, super-resolution fluorescence information reading is carried out on the writing information on the fluorescence recording layer 1, the fluorescence signal is collected by the objective lens 621, the light is split by the beam splitter 622, the light is collected into the detector 625 by the lens 624 after passing through the filter 623, and the writing information is finally decoded according to the comparison of the fluorescence intensity.

12) The objective lens position or the sample position is adjusted (process 631) to focus the excitation beam and the loss beam, respectively, on different fluorescent recording layers, thereby implementing a multi-layer information reading process for the optical disc.

Single beam writing optical disc reading and writing apparatus as shown in figure 10,

1) the writing light beam is emitted from a laser 701, after being modulated by an acousto-optic modulator 704, the laser light beam is focused by a lens 705, and a corresponding micron-level pinhole 706 is selected according to the focal length and NA of the lens 705 to filter the light beam, or a single-mode optical fiber is selected to replace the pinhole 706;

2) the divergent light beam after the space filtering of the writing light beam is collimated and expanded by a collimating lens 707, the collimated light beam is reflected by a dichroic mirror 723 and then enters a high-power objective lens 715, and the objective lens focuses to form a solid light spot with the size of the diffraction limit dimension;

3) the writing light beam acts on the physical storage medium structure 716 of the optical disc, the writing process of the lithography information is performed on the fluorescent recording layer 1, the irradiation time and the light beam intensity of the writing light beam and the inhibiting light beam are respectively controlled by the acousto-optic modulator 704, and the fluorescent writing of the recording layer 1 is accurately controlled;

4) adjusting the position of the objective lens or the sample position 724 to focus the writing light beam on different fluorescent recording layers respectively, thereby realizing the multi-layer information storage process of the optical disc;

5) for writing an optical disc, an excitation beam is emitted from a laser 702, focused by a lens 708, and filtered by a corresponding μm-level pinhole 710 selected according to the focal length and NA of the lens 708, or a single-mode fiber is selected to replace the pinhole 710;

6) the loss light beam is emitted from the laser 703, is focused by the lens 709, and the corresponding μm-level aperture 711 is selected according to the focal length and NA of the lens 709 to filter the light beam, or the single-mode fiber can be selected to replace the aperture 711;

7) the divergent light beam after the excitation light beam is spatially filtered is collimated and expanded by the collimating lens 712, the collimated light beam is reflected by the dichroic mirror 722 and then enters the high-power objective lens 715, and the objective lens focuses to form a solid light spot with the size of the diffraction limit dimension;

8) the diverging light beam after spatial filtering of the loss light beam is collimated and expanded by the collimating lens 713, the collimated light beam passes through the vortex phase plate 714 to generate a laser beam with a phase from 0 to pi, the laser beam is reflected by the dichroic mirror 721, then enters the high power objective 715, and is focused by the objective to form a hollow light beam with a central intensity approximate to zero;

9) the hollow light beam focal plane is taken as a reference, the divergence of the writing light beam is adjusted by adjusting the front and rear positions of the lens 712, the dichroic mirror 722 is adjusted, the incident angle of the writing light beam is adjusted, the writing light beam is spatially overlapped with the focal plane of the inhibition light beam and acts on the physical storage medium structure 716 of the optical disc, super-resolution fluorescence information reading is carried out on the writing information on the fluorescence recording layer 1, the fluorescence signal is collected by the objective lens 715 and is split by the beam splitter 717, the fluorescence signal passes through the filter 718 and is collected by the lens 719 into the detector 720, and the writing information is finally decoded according to the comparison of the fluorescence intensity.

10) The objective lens position or sample position is adjusted (process 724) to focus the excitation beam and the loss beam, respectively, on different fluorescent recording layers, thereby achieving a multi-layer information reading process for the optical disc.

It should be noted that both the dual-beam writing optical disc reading and writing device and the single-beam writing optical disc reading and writing device can be separated into a write-only device and a read-only device, so as to independently realize the information writing function and the information reading function.

In summary, the optical disc information reading and writing method and apparatus based on nanolithography of the present invention mainly have the following advantages:

1. the size and the distance between the recording points are reduced, and the ultrahigh-density information storage process of the optical disk is realized;

2. compared with the existing blue-ray disc, the blue-ray disc has higher stability by utilizing the change of the refractive index of the material for data storage, and is more suitable for long-term storage of information;

3. by utilizing an absorption modulation method and two-photon characteristics, the intensity and action time of the writing light and the inhibiting light are adjusted, the Gaussian intensity distribution of the transmitted light beam can be further compressed, and smaller recording spot size is realized;

4. the photoetching information writing of the multilayer fluorescent material is carried out by adopting a two-photon process, the information storage of the multilayer optical disk can be realized by utilizing the threshold effect of the two-photon process, and the mutual interference of the stored information of each layer is effectively avoided;

5. the stimulated radiation emptying technology is combined with the existing optical disk reading technology, so that the super-resolution fluorescence reading process of the optical disk storage data can be realized;

6. the size of the information recording point which is inscribed by the nano photoetching information writing method can be smaller or far smaller than 130nm of the existing blue light recording point, and the track pitch can be far smaller than 320nm of the track pitch which is achieved by the existing blue light.

Therefore, the invention effectively overcomes various defects in the prior art and has high industrial utilization value.

The foregoing embodiments are merely illustrative of the principles and utilities of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or change the above-mentioned embodiments without departing from the spirit and scope of the present invention. Accordingly, it is intended that all equivalent modifications or changes which can be made by those skilled in the art without departing from the spirit and technical spirit of the present invention be covered by the claims of the present invention.