阅读说明：本技术 石墨烯/光波导结合的微型光谱器件及光谱分析方法 (Graphene/optical waveguide combined micro spectral device and spectral analysis method ) 是由 侯俊 张陈涛 朱相宇 陶金 张建寰 于 2021-07-20 设计创作，主要内容包括：本发明公开了一种石墨烯/光波导结合的微型光谱器件及光谱分析方法,属于集成光子与硅基光电子学领域。器件包括基板、核心吸收单元和信号控制处理单元,其中核心吸收单元包括光栅耦合器、光波导、石墨烯吸收层、隔离层、介质层及调谐电极。光栅耦合器与光波导连接,石墨烯吸收层、隔离层与光波导构成空间夹心结构,调谐电极与石墨烯及介质层电连接用于电学信号施加获取。本发明的微型光谱器件将石墨烯材料与光波导进行结合,以串联结构形式对入射光谱信号进行吸收并对光电信号进行处理。所设计结构在显著提升石墨烯光吸收的同时,实现了器件面向宽光谱信号的选择性吸收及相应光电信号分析重构,对于片上微型光谱芯片和微型光谱设备的开发提供思路。(The invention discloses a graphene/optical waveguide combined micro spectral device and a spectral analysis method, and belongs to the field of integrated photonics and silicon-based optoelectronics. The device comprises a substrate, a core absorption unit and a signal control processing unit, wherein the core absorption unit comprises a grating coupler, an optical waveguide, a graphene absorption layer, an isolation layer, a dielectric layer and a tuning electrode. The grating coupler is connected with the optical waveguide, the graphene absorption layer, the isolation layer and the optical waveguide form a space sandwich structure, and the tuning electrode is electrically connected with the graphene and the dielectric layer and used for applying and acquiring electrical signals. The micro-spectral device combines the graphene material with the optical waveguide, absorbs incident spectral signals in a serial structure mode and processes the photoelectric signals. The designed structure remarkably improves the light absorption of graphene, simultaneously realizes selective absorption of the device facing to a wide spectrum signal and analysis and reconstruction of a corresponding photoelectric signal, and provides an idea for development of on-chip micro spectrum chips and micro spectrum equipment.)

1. The utility model provides a miniature spectral device that graphite alkene/optical waveguide combines, its characterized in that, includes base plate, grating coupler, optical waveguide, graphite alkene absorbed layer, tuning electrode and signal control processing unit, the grating coupler with the end to end both ends of optical waveguide are connected, and are a plurality of graphite alkene absorbed layer sets up the base plate top is followed the waveguide path direction interval arrangement of optical waveguide, the optical waveguide sets up the upper and lower both sides of graphite alkene absorbed layer form sandwich structure, and will be a plurality of graphite alkene absorbed layer concatenates, the optical waveguide with be equipped with the isolation layer between the graphite alkene absorbed layer, tuning electrode sets up graphite alkene absorbed layer top is connected with signal control processing unit.

2. The graphene/optical waveguide bonded micro-spectroscopic device of claim 1, wherein the optical waveguide comprises a first optical waveguide located above the graphene absorption layer and a second optical waveguide located below the graphene absorption layer, the second optical waveguide being embedded inside the substrate.

3. The graphene/optical waveguide bonded micro-spectroscopic device of claim 2, wherein the isolation layer comprises a first isolation layer disposed between the first optical waveguide and the graphene absorption layer and a second isolation layer disposed between the second optical waveguide and the graphene absorption layer.

4. The graphene/optical waveguide combined micro-spectroscopic device of claim 2, wherein the tuning electrode comprises a source electrode, a gate electrode, and a drain electrode, the source electrode, the gate electrode, the drain electrode, and the first optical waveguide being spaced above the graphene absorption layer, wherein the source electrode and the drain electrode are disposed on either side of the optical waveguide, and the gate electrode is disposed between the optical waveguide and the source electrode.

5. The graphene/optical waveguide bonded micro-spectroscopic device of claim 4, wherein a dielectric layer is disposed between the gate and the graphene absorption layer.

6. The graphene/optical waveguide combined micro spectral device according to claim 4, wherein the signal control processing unit comprises a voltage control module and a signal processing module, the gate and the source are respectively connected to the voltage control module, and the drain is connected to the signal processing module.

7. The graphene/optical waveguide bonded micro-spectroscopic device of claim 5, wherein the material of the grating coupler and the optical waveguide comprises SOI, the material of the isolation layer comprises hBN or alumina, and the material of the dielectric layer comprises alumina.

8. A method for spectroscopic analysis of a graphene/optical waveguide integrated micro-spectroscopic device based on any one of claims 1 to 7, comprising the steps of:

inputting a known spectrum signal into a grating coupler, and collecting a first output current generated by a drain electrode in the tuning electrode connected with each graphene absorption layer under the known spectrum signal under preset different electrical conditions;

calculating an optical response reference function of the micro spectrum device according to the first output current and the known spectrum signal;

inputting a spectral signal to be detected, collecting second output current generated by a drain electrode in the tuning electrode connected with each graphene absorption layer under the same configuration electrical condition, and calculating the spectral signal to be detected in a target wavelength range by combining the photoresponse reference function.

9. The method for spectroscopic analysis of a graphene/optical waveguide bonded micro-spectroscopic device according to claim 8, wherein the electrical conditions are: setting a first voltage between a grid electrode and a source electrode in the tuning electrode connected with each graphene absorption layer, then setting a second voltage between the source electrode and a drain electrode in the tuning electrode connected with each graphene absorption layer, and repeatedly changing the first voltage under different second voltages.

10. The method for spectroscopic analysis of a graphene/optical waveguide bonded micro-scale spectroscopic device of claim 9, wherein the relationship between the photoresponse reference function and the output current is as follows:

where λ 1 and λ 2 are the incident spectral wavelength range, Ri (λ) is the optical response reference function, F (λ) is the spectral signal, I_iThe output current measured for each of the n graphene absorption layers under the electrical condition.

Technical Field

The invention relates to the field of spectrum devices, in particular to a graphene/optical waveguide combined micro spectrum device and a spectrum analysis method.

Background

Spectral analysis is one of detection technologies widely used, and has great application value in the fields of component analysis and substance identification. With diversification and complication of application scenarios of spectral analysis, demands for miniaturized and integrated spectral analysis equipment are gradually rising. The portable small spectrometer developed on the basis of the traditional spectrometer mostly adopts a grating and an interferometer as core devices for integrated design, but the spectrometer has side effects due to the reduction of the size of an optical device when the size is reduced to a sub-millimeter level. Although some micro spectrometers can computationally reconstruct the spectral technique with multiple detectors, they still require a centimeter scale charge coupled device or CMOS array, which is difficult to further miniaturize.

The silicon-based photoelectronic technology is based on the existing silicon process platform, combines the existing microelectronic CMOS technology and the excellent photon transmission characteristic, and manufactures a photon and electron carrier functional device with micro-nano magnitude on a silicon substrate, thereby realizing a photoelectric integrated chip with complete functions. The technology can realize more efficient signal transmission and processing under the condition of not reducing the line width of the existing device, and is a potential technology of an integrated circuit chip approaching to the process limit. When the silicon-based optical waveguide structure is used as a device optical signal transmission carrier, the integration level of the device can be ensured, and meanwhile, the effective guide and limitation of incident optical signals can be realized. However, the crystal structure characteristics of the silicon-based platform limit the light absorption and light detection capability of the silicon-based platform, so that the integration process of different types of functional materials on the silicon-based platform needs to be realized in the practical device application process. Common photoelectric device materials applied to the silicon-based platform comprise germanium, oxides of three-four main groups and the like, but the difference of different materials in working wavelength and working mechanism causes the problems of high process integration difficulty, high process cost, unstable performance and the like of the conventional devices, and the miniaturization application of the silicon-based photoelectric device in the field of spectrum is limited.

In conclusion, finding a material with broad spectrum working characteristics, excellent photoelectric characteristics and good silicon-based platform compatibility is an important breakthrough for solving the application of silicon-based platform micro-spectrum devices.

Disclosure of Invention

Aiming at the problems in the prior art, the embodiment of the application provides a graphene/optical waveguide combined micro spectrum device and a spectrum analysis method to solve the problems.

First aspect, the embodiment of this application provides a miniature spectral device that graphite alkene/optical waveguide combines, including base plate, grating coupler, optical waveguide, graphite alkene absorbed layer, tuning electrode and signal control processing unit, the grating coupler with the end to end both ends of optical waveguide are connected, and are a plurality of graphite alkene absorbed layer sets up the base plate top is followed the waveguide path direction interval arrangement of optical waveguide, the optical waveguide sets up the upper and lower both sides of graphite alkene absorbed layer form sandwich structure, and will be a plurality of graphite alkene absorbed layer concatenates, the optical waveguide with be equipped with the isolation layer between the graphite alkene absorbed layer, the tuning electrode sets up graphite alkene absorbed layer top is connected with signal control processing unit.

In some embodiments, the optical waveguide comprises a first optical waveguide located above the graphene absorption layer and a second optical waveguide located below the graphene absorption layer, the second optical waveguide being embedded inside the substrate.

In some embodiments, the isolation layer comprises a first isolation layer disposed between the first optical waveguide and the graphene absorption layer and a second isolation layer disposed between the second optical waveguide and the graphene absorption layer.

In some embodiments, the tuning electrode includes a source electrode, a gate electrode, and a drain electrode, the source electrode, the gate electrode, the drain electrode, and the first optical waveguide are spaced above the graphene absorption layer, wherein the source electrode and the drain electrode are disposed on two sides of the optical waveguide, and the gate electrode is disposed between the optical waveguide and the source electrode.

In some embodiments, a dielectric layer is disposed between the gate and the graphene absorption layer.

In some embodiments, the signal control processing unit includes a voltage control module and a signal processing module, the gate and the source are respectively connected to the voltage control module, and the drain is connected to the signal processing module.

In some embodiments, the material of the grating coupler and the optical waveguide comprises SOI, the material of the isolation layer comprises hBN or alumina, and the material of the dielectric layer comprises alumina.

In a second aspect, an embodiment of the present application further provides a method for analyzing a spectrum of a micro-spectrum device based on the above graphene/optical waveguide combination, including the following steps:

inputting a known spectrum signal into a grating coupler, and collecting a first output current generated by a drain electrode in the tuning electrode connected with each graphene absorption layer under the known spectrum signal under preset different electrical conditions;

calculating an optical response reference function of the micro spectrum device according to the first output current and the known spectrum signal;

inputting a spectral signal to be detected, collecting second output current generated by a drain electrode in the tuning electrode connected with each graphene absorption layer under the same configuration electrical condition, and calculating the spectral signal to be detected in a target wavelength range by combining the photoresponse reference function.

In some embodiments, the electrical condition is: setting a first voltage between a grid electrode and a source electrode in the tuning electrode connected with each graphene absorption layer, then setting a second voltage between the source electrode and a drain electrode in the tuning electrode connected with each graphene absorption layer, and repeatedly changing the first voltage under different second voltages.

In some embodiments, the relationship between the photoresponse reference function and the output current is as follows:

where λ 1 and λ 2 are the incident spectral wavelength range, Ri (λ) is the optical response reference function, F (λ) is the spectral signal, I_iThe output current measured for each of the n graphene absorption layers under the electrical condition.

Compared with the prior art, the invention has the following beneficial effects:

(1) the excellent photoelectric characteristics of graphene are fully utilized: the graphene has the ultra-wide spectrum absorption characteristic from ultraviolet to terahertz wave bands, and has ultrahigh carrier mobility. The traditional method is limited by the limit of the absorption efficiency of single-layer graphene under the condition of vertical incidence, and cannot be well applied, and the effective absorption can be realized on the basis of increasing the optical path with the optical signal by combining with the optical waveguide. Simultaneously, the Fermi level of the graphene is tuned through an external field effect-like structure, when the incident photon energy meets the graphene absorption condition, the incident photon energy can be absorbed by the graphene to generate a photon-generated carrier, and a photon-generated current is formed under the action of an external electric field.

(2) The graphene/optical waveguide composite structure has good absorption effect: the sandwich structure is used for realizing that the graphene is positioned at the strongest position of the optical field distribution of the incident light signal, and the efficient absorption effect of the graphene in unit transmission distance is realized.

(3) The multiple graphene absorption layers are connected in series to achieve wide-spectrum signal difference absorption, absorption and photocurrent collection of different optical signals are achieved by changing tuning conditions of external electrodes of different graphene absorption layers, scanning measurement of the whole incident spectrum signal and analysis and processing of corresponding photoproduction current signals can be achieved in a scanning electric field environment, and target spectrum calculation reconstruction is achieved finally.

(4) The device has good process compatibility: the graphene and the silicon-based platform can realize good transfer adsorption, the device process is compatible with the CMOS process of the current integrated electronic device, and the process feasibility is good.

Drawings

The accompanying drawings are included to provide a further understanding of the embodiments and are incorporated in and constitute a part of this specification. The drawings illustrate embodiments and together with the description serve to explain the principles of the invention. Other embodiments and many of the intended advantages of embodiments will be readily appreciated as they become better understood by reference to the following detailed description. The elements of the drawings are not necessarily to scale relative to each other. Like reference numerals designate corresponding similar parts.

FIG. 1 is a top view of a graphene/optical waveguide combined micro-spectroscopy device according to an embodiment of the present application;

FIG. 2 is a cross-sectional view of a core absorption cell of a graphene/optical waveguide combined micro-spectroscopy device according to an embodiment of the present application;

fig. 3 is a schematic flowchart of a spectral analysis method of a micro-spectroscopic device based on graphene/optical waveguide combination according to an embodiment of the present application.

Detailed Description

The present application will be described in further detail with reference to the following drawings and examples. It is to be understood that the specific embodiments described herein are merely illustrative of the relevant invention and not restrictive of the invention. It should be noted that, for convenience of description, only the portions related to the related invention are shown in the drawings.

It should be noted that the embodiments and features of the embodiments in the present application may be combined with each other without conflict. The present application will be described in detail below with reference to the embodiments with reference to the attached drawings.

Example one

Referring to fig. 1 and fig. 2, a graphene/optical waveguide combined micro-spectral device provided in an embodiment of the present application includes a substrate 1, a grating coupler 2, an optical waveguide 3, graphene absorption layers 4, a tuning electrode 5, and a signal control processing unit 6, where the grating coupler 2 is connected to the two ends of the optical waveguide 3, and the plurality of graphene absorption layers 4 are disposed above the substrate 1 and arranged at intervals along a waveguide path direction of the optical waveguide 3. The optical signal received by the grating coupler 2 is conducted through the optical waveguide 3, the materials of the grating coupler 2 and the optical waveguide 3 comprise SOI or silicon, the material of the graphene absorption layer 4 is graphene, the thickness of the graphene absorption layer 4 is 0.5-1nm, and a single layer is preferably 0.7 nm. In a preferred embodiment, a plurality of graphene absorption layers 4 are disposed above the substrate 1 and arranged in parallel at intervals along the waveguide path direction of the optical waveguide 3. The optical waveguide 3 is arranged on the upper side and the lower side of the graphene absorption layer 4 to form a sandwich structure, the graphene absorption layers 4 are connected in series, an isolation layer 7 is arranged between the optical waveguide 3 and the graphene absorption layers 4, and the tuning electrode 5 is arranged above the graphene absorption layers 4 and connected with the signal control processing unit 6. The graphene absorption layer 4 and the optical waveguides 3 on the upper and lower sides thereof form a core absorption unit in combination with the tuning electrodes 5, as shown in fig. 2. The graphene absorption layer is used for absorbing incident spectrum signals, and the wavelengths of the incident spectrum signals absorbed by each graphene absorption layer 4 are not necessarily the same, so that the mode of serially connecting multi-core absorption units is selected, and the photoelectric signals of the graphene absorption layers 4 are collected while the incident spectrum signals are differentially absorbed by the graphene absorption layers 4 through external tuning of the signal control processing unit 6. The miniature spectral device provided by the embodiment of the application utilizes the optical waveguide to enhance the absorption of graphene to incident light signals, and simultaneously changes the optical absorption characteristics of graphene through external tuning, so that the selective absorption of the device facing to wide spectrum signals and the analysis and reconstruction of corresponding photoelectric signals are realized.

In a specific embodiment, referring to fig. 2, the optical waveguide 3 includes a first optical waveguide 31 located above the graphene absorption layer 4 and a second optical waveguide 32 located below the graphene absorption layer 4, wherein the second optical waveguide 32 is embedded inside the substrate 1, an upper surface of the second optical waveguide 32 is flush with a surface of the substrate 1, and the graphene absorption layer 4 is disposed on the surfaces of the substrate 1 and the second optical waveguide 32 and remains flat. The dimensions of the first optical waveguide 31 and the second optical waveguide 32 are 400-600nm in width and 120-130nm in thickness, preferably 500nm in width and 110nm in thickness. The isolation layer 7 comprises a first isolation layer 71 and a second isolation layer 72, the material of the isolation layer 7 comprises hBN or aluminum oxide, and the thickness of the isolation layer material is 2-10nm, preferably 5 nm. The first isolation layer 71 is disposed between the first optical waveguide 31 and the graphene absorption layer 4, the second isolation layer 72 is disposed between the second optical waveguide 32 and the graphene absorption layer 4, and the first isolation layer 71, the second isolation layer 72 and the graphene absorption layer 4 form a sandwich structure, and further form a sandwich structure with the first optical waveguide 31 and the second optical waveguide 32. The isolation layer 7 between the graphene absorption layer 4 and the optical waveguide 3 is used for preventing carriers in the graphene absorption layer 4 from being injected into the optical waveguide to influence the modulation effect when bias voltage is loaded, and the isolation layer 7 between the graphene and the graphene is used for separating the graphene and the optical waveguide to form a flat capacitor structure. The tuning electrode 5 comprises a source electrode 51, a gate electrode 52 and a drain electrode 53, and the tuning electrode 5 is made of gold/titanium and has a thickness of 40/10 nm. The source electrode 51, the gate electrode 52, the drain electrode 53 and the first optical waveguide 31 are arranged above the graphene absorption layer 4 at intervals, wherein the source electrode 51 and the drain electrode 53 are arranged on two sides of the optical waveguide 3, and the gate electrode 52 is arranged between the optical waveguide 3 and the source electrode 51. Specifically, the source electrode 51 and the drain electrode 53 are respectively located at both side edges of the substrate 1, and the source electrode 51, the gate electrode 52, the drain electrode 53 and the first optical waveguide 31 are arranged at equal intervals above the graphene absorption layer 4. The graphene absorption layer 4 between the source electrode 51 and the drain electrode 53 is similar to a series resistor, and the adjustment of the carrier type of the graphene absorption layer 4 limited within the length range of the gate electrode 52 can be realized by locally regulating the voltage of the gate electrode 52 on the graphene absorption layer 4.

In a specific embodiment, a dielectric layer 8 is disposed between the gate 52 and the graphene absorption layer 4. The thickness of the dielectric layer 8 is 10-50nm, preferably 30 nm. The material of the dielectric layer 8 disposed under the gate 52 is Al₂O₃The higher K value is beneficial to the regulation and control of the gate 52 on the conductive channel. The signal control processing unit 6 comprises a voltage control module 61 and a signal processing module 62, wherein the gate 52 and the source 51 are respectively connected with the voltage control module 61, the drain 53 is connected with the signal processing module 62, and the drain 53 is grounded. The voltage control module 61 provides the tuning voltage required by the gate 52, the source 51 and the drain 53, and the signal processing module 62 performs the processes of tuning signal input and amplification and conversion of the measurement signal. An external electric field is applied to the gate 52 and the source 51 by the voltage control module 61 so that the graphene absorption layer 4 is in different absorption states. When the energy carried by the optical signal meets the absorption condition, the optical signal is absorbed by the graphene absorption layer 4 and generates a corresponding photon-generated carrier, the electrodes of the source 51 and the drain 53 apply bias voltage to collect the carrier to obtain a corresponding photon-generated current, and the photon-generated current signal enters the signal processing module 62 to be correspondingly amplified and then subjected to conversion operation.

Based on the above graphene/optical waveguide combined micro-spectroscopy device, an embodiment of the present application further provides a spectral analysis method, as shown in fig. 3, including the following steps:

s1, inputting the known spectrum signals into the grating coupler, and collecting first output currents generated by drains in tuning electrodes connected with each graphene absorption layer under the known spectrum signals under preset different electrical conditions;

s2, calculating the light response reference function of the micro spectrum device according to the first output current and the known spectrum signal;

and S3, inputting the spectrum signal to be measured, collecting second output current generated by the drain electrode in the tuning electrode connected with each graphene absorption layer under the same configuration electrical condition, and calculating the spectrum signal to be measured in the target wavelength range by combining with the photoresponse reference function.

The spectrum reflects the distribution (relative intensity) of the optical signals of different wavelengths in the wavelength range, and the wavelength range and the relative intensity of the optical signals in a polychromatic optical signal can be seen through a spectrogram. Identification and detection of certain substances having characteristic optical wavelength signals. The light signal is incident on the detector, photoelectric conversion is carried out to obtain photocurrent of the wavelength, the current value is related to the magnitude of the light power, and the photocurrent is used as a judgment basis of the relative intensity (ordinate) of the spectrum. For a single graphene absorption layer 4, the same optical signal is incident to the micro spectrum device, and different current values can be generated by applying different voltages. The n graphene absorption layers 4 are connected in series, each graphene absorption layer 4 is fixed with different voltages, each graphene absorption layer 4 is in different absorption states of optical signals, the first graphene absorption layer 4 is at a voltage V1, the absorption of optical signals of lambda 1 is good, and other wavelengths such as lambda 2 and lambda 3 are absorbed less; the second graphene absorption layer 4 is at a voltage of V2, absorbs well λ 2 but does not absorb λ 1 and λ 3; by analogy, each graphene absorption layer 4 has a wavelength suitable for absorption, and when an optical signal with a certain wavelength range enters, each graphene absorption layer 4 generates a different current value. Therefore, when an unknown spectral signal to be detected is incident, whether the spectral signal contains a corresponding wavelength optical signal and the relative intensity of the wavelength optical signal can be judged through the current value obtained by each graphene absorption layer 4, and the spectrum of the unknown signal is obtained by reversely solving the current value.

In a specific embodiment, the device is first performance calibrated using a known single light source and a broad spectrum signal, and for a device with n core absorption units, the optical signal is coupled from an external optical fiber via a grating coupler 3 into the interior of the optical waveguide 2. The voltage control module 61 sets a first voltage between the gate 52 and the source 51 of each graphene absorption layer 4 to a predetermined voltage Vg 1-Vgn, sets a second voltage between the source 51 and the drain 53 to Vd 1-Vdn, records the output current Id 1-Idn of each graphene absorption layer 4 connecting electrode under the known optical signal, and sets the photoresponse reference function f of the device in the target wavelength range under the voltage condition according to the photo-generated current value under the known spectral signal. And repeatedly changing the first voltages Vg 1-Vgn under different second voltages to obtain the photo-generated current conditions of the calibration spectrum under different first voltages to obtain a plurality of reference functions R0-Rn under different electrical conditions. A

After the device is calibrated, inputting a spectrum signal to be measured under the same configuration voltage condition, extracting and collecting the photoproduction current of each graphene absorption layer 4, comparing the photoproduction current with the photoproduction current under the correction spectrum to judge the spectrum range, and calculating the target spectrum signal by combining the segmented photoproduction current value with the reference function. On the basis of one-time calculation operation, the absorption characteristics of the graphene absorption layers 4 are adjusted by changing the first voltages Vg 1-Vgn of the devices, and photo-generated current extraction is performed on the incident spectrum signals again. And obtaining the absorption current value of the graphene absorption layer 4 to the incident spectrum under different reference functions after multiple times of measurement and extraction operations. And solving multiple groups of photo-generated current equations under different conditions of the n graphene absorption layers 4 for photo-generated current values obtained under different tuning environments, and finally performing photo-generated current operation by using a reference function to obtain a target spectrum.

In a specific embodiment, the relationship between the photoresponse reference function and the output current is as follows:

where λ 1 and λ 2 are the incident spectral wavelength range, Ri (λ) is the optical response reference function, F (λ) is the spectral signal, I_iThe output current measured for each of the n graphene absorption layers 4 under electrical conditions.

The following specific examples illustrate the spectral analysis method in the examples of the present application:

1. setting the core absorption units 1, 2, 3 … … n connected in series to be in different regulation voltage V1, V2 and V3 … … Vn states, and setting the corresponding graphene absorption layers 4 to be in different absorption states;

2. inputting a known spectrum signal (calibration signal) to obtain output current values I1, I2 and I3 … … In of each core absorption unit electrode under the incidence of the signal;

3. obtaining a correction spectral response function R1 of output photocurrents corresponding to different wavelengths under the current set voltage, changing the voltage setting, and obtaining a plurality of correction spectral response functions R2 … … Rn;

4. testing a signal to be tested, wherein lambda 1 and lambda 2 are ranges of incident spectral signals to be tested, Ri is a pre-correction photoresponse function, F (lambda) is an optical signal to be tested, I is a photocurrent respectively measured under n core absorption units, and the following formula is used for calculating:

after an unknown optical signal F (lambda) is input, because the wavelength and the intensity of the contained optical signal are different from the corrected spectral response function, the corresponding photocurrent also has a difference, the voltage setting is changed, different corrected spectral response functions R are adopted, the integral is solved under the combination of the two functions to obtain the integral photocurrent value in the range, n integral current equations are correspondingly generated by the n corrected spectral response functions, and the original spectrum F (lambda) to be measured is solved and obtained.

According to the invention, by adopting the composite structure of the serial graphene and the optical waveguide, the light absorption effect of the graphene is improved while the light field transmission limitation is realized, the corresponding photo-generated current characteristics of the graphene in different states are obtained by using external electric field tuning, and the spectral response change of the graphene waveguide device in a wide spectral range is obtained by scanning external tuning voltage. The micro spectral device combines the graphene material with the optical waveguide, absorbs incident spectral signals in a series structure form, processes the photoelectric signals, collects the photoelectric signals while realizing differential absorption of the incident spectral signals by the graphene through external tuning, realizes analysis of unknown spectral signals, and provides a beneficial reference thought for design of the micro spectral device and miniaturization of spectral equipment. The graphene waveguide device provided by the invention reduces the material integration difficulty and the device size of the device on the basis of compounding the existing CMOS process, and has application value in the fields of micro spectrum equipment and spectrum chip development.

While the present invention has been described with reference to the preferred embodiments, it will be understood by those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention as defined by the appended claims. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

In the description of the present application, it is to be understood that the terms "upper", "lower", "inner", "outer", and the like, indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, are only for convenience in describing the present application and simplifying the description, and do not indicate or imply that the referred devices or elements must have a specific orientation, be constructed in a specific orientation, and be operated, and thus, should not be construed as limiting the present application. The word 'comprising' does not exclude the presence of elements or steps not listed in a claim. The word "a" or "an" preceding an element does not exclude the presence of a plurality of such elements. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage. Any reference signs in the claims shall not be construed as limiting the scope.