阅读说明：本技术 利用激光偏振态实现纳米光栅刻印的解决方案 (Solution for realizing nano grating imprinting by utilizing laser polarization state ) 是由 兰胜 李树磊 于 2020-05-13 设计创作，主要内容包括：本发明公开了一种利用激光偏振态实现纳米光栅刻印的解决方案,其中设计一种简单的结构,可以利用激光诱导纳米光栅制作超分辨图案,通过调节激光波长、功率、偏振方向改变纳米颗粒重塑强度和纳米光栅的取向,提出两种调节照明白光的偏振态实现颜色的调控的方法,实现对偏振的敏感感应,并得到的空间分辨率0.5微米的高分辨率、高饱和度颜色。形成的纳米光栅对反射光有偏振调控作用,利用纳米光栅对线偏振白光的保偏和旋转特性,可以在空间分辨率0.5微米的像素中识别角分辨率为10°的激光偏振态,实现超高密度光存储。相比于现有的SOI(Silicon-On-Insulator,绝缘衬底上的硅)刻蚀工艺,本发明的方案制作方法简单,没有复杂的工艺。(The invention discloses a solution for realizing nano grating imprinting by utilizing a laser polarization state, wherein a simple structure is designed, a super-resolution pattern can be manufactured by utilizing laser to induce a nano grating, the remolding intensity of nano particles and the orientation of the nano grating are changed by adjusting the laser wavelength, the power and the polarization direction, two methods for adjusting the polarization state of illumination white light to realize color regulation and control are provided, the polarization sensitive induction is realized, and the obtained high-resolution and high-saturation color with the spatial resolution of 0.5 micrometer is obtained. The formed nano grating has a polarization regulation effect on reflected light, and by utilizing the polarization maintaining and rotating characteristics of the nano grating on linearly polarized white light, the laser polarization state with the angular resolution of 10 degrees can be identified in pixels with the spatial resolution of 0.5 micron, so that ultrahigh-density optical storage is realized. Compared with the existing SOI (Silicon-On-Insulator) etching process, the scheme of the invention has the advantages of simple manufacturing method and no complex process.)

1. A sample for realizing nano grating imprinting by utilizing a laser polarization state is characterized by sequentially comprising a substrate, a metal film layer, a medium isolation layer and a metal nano island layer from a bottom layer to a top layer.

2. The sample for realizing nano-grating imprinting by utilizing the polarization state of the laser according to claim 1, wherein the substrate plays a supporting role and is made of a hard flat material of glass or a silicon wafer; the thickness of the metal film layer is more than 100nm, and the metal film layer is plated on the substrate by adopting a metal material of gold, silver, platinum or aluminum through a method of evaporation plating or ion sputtering; the medium isolation layer is made of a flexible material or a hard material, the flexible material is an organic matter film and comprises PMMA, PVP or PVA, the metal film layer is prepared by using a film throwing machine, and the film throwing speed and the film throwing time are controlled to realize the thicknesses of different films; the hard material is glass or ceramic, comprises silicon oxide, aluminum oxide, calcium nitride or calcium carbide, and is prepared by evaporation or chemical vapor deposition; the metal nano island layer is prepared by a particle sputtering method, a metal material of gold, silver, platinum or aluminum is adopted, and the size of metal nano particles is controlled on the medium isolating layer by adjusting the sputtering time and current.

3. A laser direct writing device for realizing nanometer grating imprinting by utilizing a laser polarization state is characterized by comprising the sample of any one of claims 1-2, a femtosecond laser system, a laser polarization adjusting device, a shutter, a laser focusing device, a micro-sodium displacement table and a PC (personal computer) provided with a laser direct writing control program;

the sample is placed on the micro-sodium displacement table, and the metal nano island layer of the sample faces to an objective lens port of the laser focusing device;

the femtosecond laser system outputs femtosecond pulse mode-locked laser, and the laser polarization adjusting device is used for generating different polarization states of the femtosecond pulse mode-locked laser; outputting polarized light with different polarization states, coupling the polarized light into an objective lens of a laser focusing device through a shutter, and focusing the polarized light on the surface of the metal nano island layer; the laser acts on the metal nanometer island layer of the sample, the high-energy remolded metal nanometer island of the femtosecond pulse mode-locked laser is changed into metal nanometer particles and is arranged regularly to form a nanometer grating structure, and the nanometer scale imprinting is realized;

the laser direct-writing control program controls the movement of the micro-sodium displacement table to enable laser to act on a set area, the laser direct-writing control program controls the opening and closing of the shutter, the shutter controls the on-off of the laser, and the direct writing of a single pixel and a discontinuous area is realized.

4. The laser direct writing device for realizing nano grating imprinting by utilizing the laser polarization state as claimed in claim 3, wherein the laser polarization adjusting device comprises 1/2 glass slide and 1/4 glass slide, the femtosecond pulse mode-locked laser sequentially passes through 1/2 glass slide and 1/4 glass slide, the two glass slides are rotated to obtain different combinations, and polarized light with different polarization states is adjusted and controlled.

5. The laser direct writing device for realizing nano grating imprinting by utilizing the laser polarization state as claimed in claim 3, wherein the wavelength of the femtosecond pulse mode-locked laser is changed, so that the remolding and imprinting of the metal nano island by the laser with different wavelengths are different in intensity, and finally the formed appearance is also different, thereby controlling the pattern to present different colors;

the power of the femtosecond pulse mode-locked laser is changed, so that the remolding and the imprinting of the metal nanometer island by the laser with different powers are different in strength, the finally formed appearances are also different, and the patterns are controlled to present different colors;

and changing the polarization state of the femtosecond pulse mode-locked laser to ensure that the laser with different polarization directions remodels the metal nano island into different orientations of the metal nano particles and different arrangement directions after etching, so as to control the pattern to present different colors.

6. The laser direct writing device for realizing nano grating imprinting by utilizing the laser polarization state according to claim 3, wherein the laser direct writing device splits a binary image to be imprinted according to colors, introduces the split image into the laser direct writing control program, sets a group of parameters of laser wavelength, laser power and laser polarization direction according to different colors for each split image, and then the laser direct writing control program links the opening and closing of a shutter and a micro sodium displacement table to move a sample to complete the imprinting of the pattern on the sample.

7. The laser direct writing device for realizing nanometer grating imprinting by utilizing the laser polarization state as claimed in claim 3, wherein the size of the pixel is adjusted by setting the moving step length of the micro sodium displacement table to realize the adjustment of the resolution.

8. A detection mechanism for realizing nanometer grating imprinting by utilizing a laser polarization state realizes sensitive response of colors to polarization, and is characterized in that the detection mechanism comprises a first natural light source, a first adjustable analyzer and a first observation device;

incident natural light irradiated by a first natural light source is perpendicularly irradiated on an image engraved by laser, a first adjustable analyzer is placed on a reflection light path, the angle of a light transmission shaft of the first adjustable analyzer is adjusted, reflected light in different polarization directions penetrates through the first adjustable analyzer, and the color change of the pattern of the engraved image under different analysis angles is observed through a first observation device.

9. A detection mechanism for realizing nanometer grating imprinting by utilizing laser polarization state realizes sensitive response of color to polarization, and is characterized in that the detection mechanism comprises a second natural light source, a first adjustable polarizer and a second observation device;

incident natural light irradiated by the second natural light source is perpendicularly irradiated on the first adjustable polarizer and then irradiated on the laser engraved image, the angle of the light transmission shaft of the first adjustable polarizer is adjusted, the polarization direction of white light is changed, white light in different polarization directions is irradiated on the engraved image, and color change of the pattern under the irradiation of the white light in different polarization directions is observed through the second observation device.

10. The orthogonal polarization analyzer is characterized by comprising a third natural light source, a second adjustable polarizer, a second adjustable analyzer and a third observation device;

incident natural light irradiated by a third natural light source is adjusted into linearly polarized light after passing through a second adjustable polarizer and is irradiated on the pattern of the laser inscription, reflected light passes through a second adjustable analyzer and is observed on the pattern of the laser inscription through a third observation device, wherein the direction of a light transmission axis of the second adjustable analyzer is always vertical to the direction of the light transmission axis of the second adjustable polarizer, and the observed pattern of the laser inscription presents different light and shade phenomena;

only when the vector direction of the laser-imprinted nano grating is consistent with or perpendicular to the direction of the light transmission axis of the second adjustable polarizer, the polarization direction of the reflected light is consistent with the polarization direction of the incident light, and the reflected light cannot be observed through the second adjustable analyzer and appears black; when the vector direction of the laser-imprinted nano grating and the transmission axis direction of the second adjustable polarizer are between 0 and 90 degrees, the polarization direction of the reflected light rotates and forms an included angle with the polarization direction of the incident light, so that the reflected light can still penetrate through the second adjustable analyzer, and the pattern shape is observed; when the vector direction of the nano grating and the light transmission axis direction of the adjustable polarizer form an included angle of 45 degrees, the rotating capability is 45 degrees at most, the reflection light transmittance is the largest, and the brightness of the pattern is the largest; the polarization maintaining and rotating characteristics of the nanometer grating to the polarized white light are utilized to realize the reading of the laser writing patterns in the specific polarization direction, obtain the resolution of the polarization state and realize the ultra-high density optical storage.

Technical Field

The invention relates to the technical field of laser-induced periodic structures and color display, in particular to a solution for realizing nanometer grating imprinting by utilizing a laser polarization state.

Background

Color plays an important role in various industries as an important sensory medium. The continuous development of micro-sodium technology and materials and the regulation and control technology of light have been from the passive utilization of the limited optical properties of natural materials to the active construction of metamaterials with specific optical characteristics, wherein plasma color has huge potential. By utilizing the plasma sub-wavelength structure and designing different geometric dimensions, the near field and far field regulation and control of an optical field can be realized by selectively enhancing or blocking any resonance wavelength. Most of the periodic nanoparticles, nanorods or nanopores are prepared by electron beam etching and ion beam etching, and have the disadvantages of high price, incapability of large-area manufacturing and lack of dynamic adjustability. The laser-induced periodic structures (LIPSs) technology can directly prepare nano grating structures on the surfaces of different body materials, avoids complex photoetching process, can realize marking of polarized-oriented sub-wavelength spatial resolution, mainly prepares two-dimensional ordered linear microstructures, and is difficult to display rich colors. Therefore, in the fields of color display and optical storage, the identification of the polarization state and the practical application of the super-resolution polarization footprint by the laser direct writing technology are still to be further explored.

Disclosure of Invention

In view of the above, the present invention provides a solution for achieving nano-grating imprinting using laser polarization state, and is used for super-resolution color-sensitive display and ultra-high density optical storage.

The invention solves the problems through the following technical means:

on one hand, the invention provides a sample for realizing nano grating imprinting by utilizing a laser polarization state, wherein the sample sequentially comprises a substrate, a metal film layer, a medium isolation layer and a metal nano island layer from a bottom layer to a top layer; the substrate plays a supporting role and can be made of hard flat materials such as glass materials, silicon wafers and the like; the thickness of the metal film layer is more than 100nm, the material can be gold, silver, platinum, aluminum and other metals, and the metal film layer is plated on the substrate by a method of evaporation plating or ion sputtering; the medium isolation layer is made of a flexible material or a hard material, the flexible material can be an organic matter film, such as PMMA (polymethyl methacrylate), PVP (polyvinyl pyrrolidone), PVA (polyvinyl alcohol) and other materials, the metal film layer is prepared by using a film throwing machine, and the film throwing speed and the film throwing time are controlled to realize the thicknesses of different films; the hard material can be glass or ceramic, such as materials of silicon oxide, aluminum oxide, calcium nitride, calcium carbide and the like, and can be prepared by evaporation, chemical vapor deposition or other methods; the metal nano island layer is prepared by a particle sputtering method, the material can be gold, silver, platinum, aluminum and other metals, and the size of metal nano particles is controlled on the medium isolating layer by adjusting the sputtering time and current.

On the other hand, the invention also provides a laser direct writing device for realizing nanometer grating imprinting by utilizing the laser polarization state, which comprises a femtosecond laser system, a laser polarization adjusting device, a shutter, a laser focusing device, a micro-sodium displacement table and a PC (personal computer) provided with a laser direct writing control program; the sample is placed on the micro-sodium displacement table, a metal nano island layer of the sample faces an objective lens port of a laser focusing device, a laser beam emitted by the femtosecond laser system sequentially passes through the laser polarization adjusting device, the shutter and the laser focusing device, the laser beam is focused on the metal nano island layer of the sample through the laser focusing device, the micro-sodium displacement table and the shutter are controlled by using a laser direct writing control program, and pattern writing is realized by moving the micro-sodium displacement table.

The wavelength of the femtosecond laser is changed, so that the remolding and the imprinting of the metal nanometer island by the laser with different wavelengths are different in strength, the finally formed appearance is also different, and the pattern is controlled to present different colors.

The power of the femtosecond laser is changed, so that the remolding and the imprinting of the metal nanometer island are different in strength by the laser with different powers, the finally formed appearance is also different, and the pattern is controlled to present different colors.

And changing the polarization state of the femtosecond laser to ensure that the laser with different polarization directions has different orientations and arrangement directions after etching for remolding the metal nano island into metal nano particles, so as to control the pattern to present different colors.

And (3) introducing the binary image into a laser direct writing control program, guiding the micro-sodium displacement table to move on a 2-dimensional plane according to the pattern requirement, and regulating the laser writing or closing by controlling a shutter switch so as to facilitate the femtosecond laser direct writing of the discontinuous pattern.

The size of the pixel can be adjusted by setting the moving step length of the micro-sodium displacement table, so that the adjustment of the resolution ratio is realized.

In another aspect, the invention further provides a detection mechanism for realizing nanometer grating imprinting by utilizing the polarization state of laser, so that sensitive response of color to polarization is realized. The detection mechanism comprises two types: the first type comprises a first natural light source, a first adjustable analyzer and a first observation device; incident natural light irradiated by a first natural light source is perpendicularly irradiated on an image of laser engraving, a first adjustable analyzer is placed on a reflection light path, the polarization direction of the first adjustable analyzer is adjusted to obtain linear polarization reflection light in different polarization directions, the linear polarization reflection light in different polarization directions can display different colors, and the color change of the pattern of the engraving image under different polarization angles is observed through a first observation device; the second comprises a second natural light source, a first adjustable polarizer and a second observation device; incident natural light irradiated by the second natural light source is perpendicularly irradiated on the first adjustable polarizer and then irradiated on the laser engraved image, the angle of the light transmission shaft of the first adjustable polarizer is adjusted, the polarization direction of white light is changed, white light in different polarization directions is irradiated on the engraved image, and color change of the pattern under the irradiation of the white light in different polarization directions is observed through the second observation device. Both patterns can be observed with the same effect.

In another aspect, the invention further provides a detection mechanism orthogonal polarization analyzer for realizing the nanometer grating imprinting by utilizing the laser polarization state, and the angle resolution of the laser polarization state is identified. The orthogonal polarization analyzer of the detection mechanism comprises a third natural light source, a second adjustable polarizer, a second adjustable analyzer and a third observation device; incident natural light irradiated by a third natural light source is adjusted into linearly polarized light after passing through a second adjustable polarizer and is irradiated on the pattern of the laser inscription, reflected light passes through a second adjustable analyzer and is used for observing the pattern of the laser inscription through a third observation device, wherein the light transmission axis direction of the second adjustable analyzer is always vertical to the light transmission axis direction of the second adjustable polarizer, and the pattern of the laser inscription observed under the device presents different light and shade phenomena. Only when the vector direction of the laser-imprinted nano grating is consistent with or perpendicular to the direction of the light transmission axis of the second adjustable polarizer, the polarization direction of the reflected light is consistent with the polarization direction of the incident light, and the reflected light cannot be observed through the second adjustable analyzer and appears black; when the vector direction of the laser-imprinted nano grating and the transmission axis direction of the second adjustable polarizer are between 0 and 90 degrees, the polarization direction of the reflected light rotates and forms an included angle with the polarization direction of the incident light, so that the reflected light can still pass through the second adjustable analyzer, and the pattern shape can be observed. When the vector direction of the nano grating and the light transmission axis direction of the adjustable polarizer form an included angle of 45 degrees, the rotating capability is 45 degrees at most, the reflection light transmittance is the largest, and the brightness of the pattern is the largest; the pixel with 0.5 micron multiplied by 0.5 micron can realize 9 polarization states and 10 DEG angular resolution, and realize ultra-high density optical storage.

Compared with the prior art, the invention has the beneficial effects that at least:

the invention can utilize laser to induce the nanometer grating to make super-resolution pattern, change the remolding intensity of nanometer granule and orientation of nanometer grating by regulating laser wavelength, power, polarization direction, propose two kinds of methods of adjusting the polarization state of the white light of illumination and realizing the regulation and control of the color, realize the sensitive induction of the color to the polarization, and the high resolution, high saturation color of the spatial resolution 0.5 micron that is got. The formed nanometer grating has polarization maintaining and rotating characteristics on polarized light, can identify the laser polarization state with the spatial resolution of 0.5 micron and the angular resolution of 10 degrees, and realizes ultrahigh-density optical storage. Compared with the existing SOI (Silicon-On-Insulator, Silicon On an insulating substrate) etching process, the scheme of the application has the advantages that the manufacturing method is simple, and the micro-sodium scale pattern close to the diffraction limit and the ultra-high density optical storage can be obtained without a complex etching process.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed to be used in the description of the embodiments will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.

FIG. 1 is a schematic structural diagram of a sample for implementing nano-grating imprinting by using a laser polarization state according to the present invention;

FIG. 2 is a Transmission Electron Microscope (TEM) image of gold nano-islands on top of a sample of the present invention;

FIG. 3 is a schematic structural diagram of a laser direct writing device for realizing nano-grating imprinting by utilizing a laser polarization state according to the present invention;

FIG. 4 is a diagram showing the effect of the laser beams with different polarization states focused on the gold nano-island according to the present invention;

FIG. 5 is a schematic structural diagram of a first detection mechanism for implementing nano-grating imprinting by using laser polarization state according to the present invention;

FIG. 6 is a schematic structural diagram of a second detection mechanism for implementing nano-grating imprinting by using laser polarization state according to the present invention;

FIG. 7 is a color chart of patterns written with the same laser power at different laser wavelengths under white light of the same polarization direction according to the present invention;

FIG. 8 is a color chart of patterns made according to the present invention viewed under different polarized white light;

FIG. 9 is a schematic structural diagram of an orthogonal polarization analyzer of a detection mechanism for realizing nanometer grating imprinting by utilizing a laser polarization state according to the present invention;

FIG. 10 is a diagram of the effect of the ultra-high density optical storage made by the present invention.

Description of reference numerals:

1. a sample; 11. a substrate; 12. a metal thin film layer; 13. a dielectric isolation layer; 14. a metallic nano-island layer; 21. a femtosecond laser system; 22. a laser polarization adjustment device; 221. 1/2 slide glass; 222. 1/4 slide glass; 23. a shutter; 24. a laser focusing device; 241. a total reflection mirror; 242. an objective lens; 25. a micro-sodium displacement stage; 26. a PC machine; 31. a first adjustable analyzer; 32. a first observation device; 41. a first tunable polarizer; 42. a second observation device; 51. a second adjustable analyzer; 52. a third observation device; 53. a second tunable polarizer.

Detailed Description

In order to make the aforementioned objects, features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in detail below. It should be noted that the described embodiments are only a part of the embodiments of the present invention, and not all embodiments, and all other embodiments obtained by those skilled in the art without any inventive work based on the embodiments of the present invention belong to the protection scope of the present invention.