Optical waveguide layer and method of manufacturing and use thereof

Abstract

The application provides an optical waveguide layer and a preparation method and application thereof, and belongs to the technical field of filter devices. The application deposits a thin film on a photonic crystal grating substrate as an optical waveguide layer by an atomic layer deposition method, and can obtain an optical waveguide layer thin film with different refractive indexes by adjusting the temperature of heat treatment. The guided mode resonance filter made of the optical waveguide layer thin film can produce a high reflectivity close to 100% in a resonance waveband (a resonance waveband in the range of 259-1500 nm), and the waveband of resonance reflection is very sensitive to the refractive index of the grating area filling material. By adjusting the thickness and refractive index of the optical waveguide layer thin film, the precise control of different range resonance wavebands of the guided mode resonance filter device is realized, a high-efficiency guided mode resonance filter is prepared, and the application on the device is realized.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of filter devices, in particular to an optical waveguide layer and a preparation method and application thereof. BACKGROUND

[0002] Guided-mode resonance filter (GMR) is a kind of photonic crystal resonant reflector, which has perfect resonant reflection of any narrow band for some polarization of incident light, while allowing other bands of light to continue transmission. There are few domestic researches on optical waveguide layer based on guided-mode resonance filter application. The optical waveguide layer can effectively regulate the matching light, and is applied to optical filter to realize guided-mode resonance effect, so that the grating has high reflection or transmission characteristics at the resonance wavelength. In 2013, Uddin et al. [Uddin MJ, Magnusson R. Guided-Mode Resonant Thermo-Optic Tunable Filters [J]. IEEE Photonics Technology Letters, 2013, 25 (15): 1412-1415] proposed a method of realizing wavelength tunable guided-mode resonance filter by thermo-optic modulation, and realized wavelength tunable range of 15 nm and 12 nm by using deep etching and shallow etching grating respectively. In 2015, Xiao Guohui et al. [Xiao GH, Zhu QZ, Shen Y, et al. A tunable submicro-optofluidic polymer filter based on guided-mode resonance [J. Nanoscale, 2015, 7 (8): 3429-3434] realized a tunable guided-mode resonance filter with a width of 13.181 nm by injecting fluid polymer materials with different refractive indexes into the air gap of the multilayer grating to change the effective refractive index of the grating.

[0003] However, the above prior art method realizes the wavelength adjustment of the guided-mode resonance filter, but the preparation process is harsh and the operation is complex, which is difficult to apply in practice. SUMMARY

[0004] The purpose of the present application is to provide an optical waveguide layer and a preparation method and application thereof, which can simply and accurately control the resonance band range of the guided-mode resonance filter device.

[0005] In order to achieve the above-mentioned purpose of the application, the present application provides the following technical solutions:

[0006] The present application provides a preparation method of an optical waveguide layer, comprising the following steps:

[0007] The filter precursor source is subjected to atomic layer deposition on a substrate under an oxygen-containing condition to obtain a deposition film;

[0008] The deposition film is subjected to heat treatment to obtain an optical waveguide layer.

[0009] Preferably, the filter precursor source comprises tetrakis(dimethylamino) titanium, bis(tert-butylamino)silane, trimethyl gallium or arsine.

[0010] Preferably, the substrate is a substrate with a periodic pattern on the surface; the hole shape of the periodic pattern is a strip grating, a circle, a triangle, a rectangle or a polygon; and the material of the substrate is quartz glass, silicon, anodized aluminum or an organic substance.

[0011] Preferably, the oxygen source used in the oxygen-containing condition comprises water or ozone.

[0012] Preferably, the atomic layer deposition is performed under the following conditions: the inert gas flow is 5-50 sccm, the pressure in the deposition cavity is 20-100 Pa, the deposition time is 20-200 h, the vacuum degree in the deposition cavity is <0.1 Pa, and the temperature of the substrate is 50-200℃.

[0013] Preferably, the inert gas comprises nitrogen, argon or helium.

[0014] Preferably, the thickness of the deposition film is 20-1000 nm.

[0015] Preferably, the heat treatment is performed at a temperature of 150-450℃ for 20-60 h.

[0016] The application provides an optical waveguide layer prepared by the preparation method.

[0017] The application provides an application of the optical waveguide layer in a guided-mode resonance filter.

[0018] The application provides a preparation method of an optical waveguide layer, comprising the following steps: performing atomic layer deposition on a substrate under an oxygen-containing condition by using a filter precursor source to obtain a deposited film; and performing heat treatment on the deposited film to obtain the optical waveguide layer. The film is deposited on a photonic crystal grating substrate as the optical waveguide layer by the atomic layer deposition method, the optical waveguide layer film with different refractive indexes can be obtained by adjusting the heat treatment temperature, the guided mode resonance filter made of the optical waveguide layer film can produce high reflectivity close to 100% in the resonance band (the resonance band in the range of 259-1500 nm), the resonance reflection band is very sensitive to the refractive index of the grating substrate filling material, the thickness and refractive index of the optical waveguide layer film are adjusted to realize the precise control of the guided mode resonance filter device in different ranges of resonance band, the high-efficiency guided mode resonance filter is prepared, and the application of the device is realized.

[0019] The atomic layer deposition method can be used to prepare the optical waveguide layer film, the atomic layer deposition method can accurately grow various heterostructures, obtain steep interface layers, and obtain high-quality films, is simple to operate, easy to control in the process, and is conducive to the practical application of actual devices.

[0020] Further, the working gas pressure, gas flow, deposition temperature, deposition time and heat treatment temperature are controlled, so that the prepared optical waveguide layer film has good crystalline quality and high density, and is conducive to the application on the device. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 X-ray diffraction pattern of the titanium dioxide optical waveguide layer film prepared in Example 1;

[0022] Figure 2 Field emission scanning electron microscope photo of the titanium dioxide optical waveguide layer film prepared in Example 1;

[0023] Figure 3 Refractive index curve pattern of the titanium dioxide optical waveguide layer film prepared in Examples 1-3 obtained by using an ellipsometer for testing;

[0024] Figure 4 Guided mode resonance filter structure schematic diagram made of the optical waveguide layer films prepared in Examples 1-3;

[0025] Figure 5 Resonance band pattern of the titanium dioxide optical waveguide layer film prepared in Examples 1-3. DETAILED DESCRIPTION

[0026] The application provides a preparation method of an optical waveguide layer, comprising the following steps:

[0027] The filter precursor source is subjected to atomic layer deposition on a substrate under an oxygen-containing condition to obtain a deposition film;

[0028] The deposition film is subjected to heat treatment to obtain an optical waveguide layer.

[0029] In the present application, the required materials or reagents are all commercially available unless otherwise specified.

[0030] The filter precursor source is subjected to atomic layer deposition on a substrate under an oxygen-containing condition to obtain a deposition film.

[0031] In the present application, the oxygen source used in the oxygen-containing condition includes water or ozone.

[0032] In the present application, the filter precursor source preferably includes tetrakis(dimethylamino) titanium, bis(tert-butylamino)silane, trimethyl gallium or arsine.

[0033] In the present application, the substrate is preferably a substrate with a periodic pattern on the surface; the hole shape of the periodic pattern is preferably a strip grating, a circle, a triangle, a rectangle or a polygon; and the material of the substrate is preferably quartz glass, silicon, anodized aluminum or an organic substance. The present application does not have special limitations on the specific periodic arrangement and periodic form of the substrate, and any periodic substrate known in the art that can be used as a grating layer can be used; in the embodiments of the present application, quartz glass with a two-dimensional circular periodic pattern is used as the substrate material, and the arrangement period is 700 nm.

[0034] Before the atomic layer deposition, the substrate is preferably cleaned to remove the contaminants on the surface; the cleaning liquid used in the cleaning is preferably a mixture of concentrated sulfuric acid and hydrogen peroxide, and the volume ratio of the concentrated sulfuric acid to the hydrogen peroxide is preferably 7:3; the mass fraction of the concentrated sulfuric acid is preferably 98%, and the mass fraction of the hydrogen peroxide is preferably 30%. In the present application, the cleaning process is preferably that the substrate is immersed in the cleaning liquid for 30 min to sufficiently remove the organic substances on the surface, then the substrate is repeatedly washed with deionized water for 10 min, and then the substrate is ultrasonically cleaned with deionized water for 20 min. The present application does not have special limitations on the ultrasonic frequency of the ultrasonic cleaning, and any ultrasonic frequency known in the art can be used. After the cleaning is completed, the obtained substrate is preferably blown dry with high-purity nitrogen in a hundred-level clean room, and the purity of the high-purity nitrogen is preferably ≥ 99.999%.

[0035] In the present application, the atomic layer deposition is preferably carried out in an atomic layer deposition machine; the present application preferably places the cleaned and dried substrate into the deposition cavity of the atomic layer deposition machine, opens the mechanical pump to extract vacuum to the required vacuum degree, introduces inert gas, heats the substrate, maintains the stability of the gas pressure and temperature, introduces the precursor source and oxygen source, starts the atomic layer deposition machine, and carries out atomic layer deposition. In the present application, the pulse time of the precursor source is preferably 0.015-0.05 s, more preferably 0.02 s, the purge time is preferably 10-15 s, the pulse time of the oxygen source is preferably 0.02-0.05 s, more preferably 0.03 s, and the purge time is preferably 15-20 s. The present application controls the amount of the precursor source and the oxygen source by pulse time, and controls the film thickness by the amount of the precursor source.

[0036] In the present application, the conditions of the atomic layer deposition preferably include: the inert gas flow is 5-50 sccm, more preferably 20-50 sccm, the gas pressure of the deposition cavity is 20-100 Pa, more preferably 35-60 Pa; the deposition time is 20-200 h, more preferably 50-100 h; the vacuum degree of the deposition cavity is <0.1 Pa; and the temperature of the substrate is 50-200℃, more preferably 100-150℃. The present application does not have special limitations on the atomic layer deposition machine, and the corresponding devices known in the art can be used.

[0037] In the present application, the inert gas preferably includes nitrogen, argon or helium. In the process of the atomic layer deposition, the present application preferably continuously introduces inert gas, and maintains the dynamic balance of the gas pressure in the cavity, so as to ensure the stability of the gas content in the cavity, and is conducive to improving the growth quality of the film.

[0038] After the atomic layer deposition is completed, the present application preferably closes the heating source and the mechanical pump; after the temperature of the substrate decreases to room temperature, nitrogen is introduced into the cavity to atmospheric pressure, the cavity is opened, and the deposited film is taken out.

[0039] In the present application, the thickness of the deposited film is preferably 20-1000 nm, more preferably 110-210 nm. The present application preferably adjusts the thickness of the deposited film by the deposition time.

[0040] After the deposited film is obtained, the present application carries out heat treatment on the deposited film to obtain an optical waveguide layer.

[0041] In the present application, the temperature of the heat treatment is preferably 150-450℃, more preferably 300-400℃; and the time is preferably 20-60 h, more preferably 40 h. The present application does not have special limitations on the equipment used for the heat treatment, and the corresponding devices known in the art that can reach the required temperature can be used. The present application obtains optical waveguide layer films with different refractive indexes by heat treatment at different temperatures by adjusting the heat treatment temperature.

[0042] The application provides the optical waveguide layer prepared by the preparation method.

[0043] The application provides application of the optical waveguide layer in a mode filter.

[0044] The technical solutions in the application will be clearly and completely described below with reference to the embodiments in the application. Obviously, the described embodiments are only some of the embodiments of the application, but not all the embodiments. Based on the embodiments in the application, all other embodiments obtained by a person of ordinary skill in the art without creative work fall within the protection scope of the application.

[0045] Embodiment 1

[0046] Quartz glass with a two-dimensional circular periodic pattern prepared by a nanoimprint technology is used as a substrate material, the arrangement period is 700 nm, a cleaning solution with a volume ratio of concentrated sulfuric acid to hydrogen peroxide solution of 7:3 is configured, the mass fraction of the concentrated sulfuric acid is 98%, the mass fraction of the hydrogen peroxide is 30%, the substrate material is immersed in the cleaning solution for 30 min, is repeatedly washed with deionized water for 10 min, is ultrasonically cleaned with deionized water for 20 min, is dried by blowing high-purity nitrogen (purity ≥ 99.999%) in a hundred-level clean room, and is placed in a deposition cavity;

[0047] A mechanical pump is started to extract vacuum, so that the vacuum degree of the cavity is less than 0.1 Pa; nitrogen gas is introduced at a flow rate of 5 sccm, and the cavity pressure is kept at 20 Pa; the substrate is heated, so that the temperature of the substrate is kept at 100 ℃;

[0048] After the pressure and the substrate temperature are stabilized, a four (dimethylamine methyl) titanium precursor source and water are introduced, the pulse time of the precursor source is 0.015 s, the purge time is 10 s, the pulse time of the water is 0.02 s, the purge time is 15 s, the atomic layer deposition machine is started to deposit, the deposition time is 20 h, and the thickness of the deposited film is 20 nm;

[0049] After the deposition is completed, the heating source and the mechanical pump are turned off; after the temperature of the substrate decreases to room temperature, nitrogen gas is introduced into the cavity to reach the atmospheric pressure, the cavity is opened, and the deposited film is taken out;

[0050] The deposited film is taken out, and is subjected to heat treatment, the heat treatment temperature is 150 ℃, the heat treatment time is 40 h, and the optical waveguide layer film is obtained.

[0051] Embodiment 2

[0052] The quartz glass with two-dimensional circular periodic pattern prepared by nano-imprinting technology is used as a substrate material, the arrangement period is 700 nm, a cleaning solution with a volume ratio of concentrated sulfuric acid to hydrogen peroxide solution of 7:3 is configured, the mass fraction of concentrated sulfuric acid is 98%, and the mass fraction of hydrogen peroxide is 30%; the substrate material is soaked in the cleaning solution for 30 min, repeatedly washed with deionized water for 10 min, and then ultrasonically cleaned with deionized water for 20 min; the substrate material is dried in a hundred-level clean room by blowing high-purity nitrogen (purity ≥ 99.999%) and placed in a deposition chamber;

[0053] A mechanical pump is started to extract vacuum, so that the vacuum degree of the chamber is less than 0.1 Pa; nitrogen gas is introduced at a flow rate of 20 sccm, and the chamber pressure is maintained at 35 Pa; the substrate is heated, so that the temperature of the substrate is maintained at 150°C;

[0054] After the pressure and the substrate temperature are stabilized, the four (dimethylamine methyl) titanium precursor source and water are introduced, the precursor source pulse time is 0.025 s, the purge time is 10 s, the water pulse time is 0.03 s, and the purge time is 15 s; the atomic layer deposition machine is started to deposit, the deposition time is 50 h, and the thickness of the deposited film is 110 nm;

[0055] After the deposition is completed, the heating source and the mechanical pump are turned off; after the temperature of the substrate decreases to room temperature, nitrogen gas is introduced into the chamber to reach atmospheric pressure, and the chamber is opened to take out the deposited film;

[0056] The deposited film is taken out and subjected to heat treatment, the heat treatment temperature is 300°C, the heat treatment time is 40 h, and the optical waveguide layer film is obtained.

[0057] Example 3

[0058] The quartz glass with two-dimensional circular periodic pattern prepared by nano-imprinting technology is used as a substrate material, the arrangement period is 700 nm, a cleaning solution with a volume ratio of concentrated sulfuric acid to hydrogen peroxide solution of 7:3 is configured, the mass fraction of concentrated sulfuric acid is 98%, and the mass fraction of hydrogen peroxide is 30%; the substrate material is soaked in the cleaning solution for 30 min, repeatedly washed with deionized water for 10 min, and then ultrasonically cleaned with deionized water for 20 min; the substrate material is dried in a hundred-level clean room by blowing high-purity nitrogen (purity ≥ 99.999%) and placed in a deposition chamber;

[0059] A mechanical pump is started to extract vacuum, so that the vacuum degree of the chamber is less than 0.1 Pa; nitrogen gas is introduced at a flow rate of 20 sccm, and the chamber pressure is maintained at 35 Pa; the substrate is heated, so that the temperature of the substrate is maintained at 150°C;

[0060] After the pressure and the substrate temperature are stabilized, the four (dimethylamine methyl) titanium precursor source and water are introduced, the precursor source pulse time is 0.025 s, the purge time is 10 s, the water pulse time is 0.03 s, and the purge time is 15 s; the atomic layer deposition machine is started to deposit, the deposition time is 50 h, and the thickness of the deposited film is 110 nm;

[0061] After the deposition, the heating source and the mechanical pump are turned off; after the temperature of the substrate decreases to room temperature, nitrogen is introduced into the chamber to reach atmospheric pressure, and the chamber is opened to take out the deposited film;

[0062] The deposited film is taken out and subjected to heat treatment at a temperature of 400°C for 60h to obtain the optical waveguide layer film.

[0063] Characterization and performance test

[0064] 1) The optical waveguide layer film sample prepared in Example 1 is characterized by X-ray diffraction and scanning electron microscopy, and the results are shown in Figures 1-2 Figure 1 It can be seen from the results that the optical waveguide layer film prepared in Example 1 is anatase titanium dioxide; and Figure 2 It can be seen from the results that the surface of the titanium dioxide film prepared in Example 1 is smooth and has high density.

[0065] 2) The optical waveguide layer film samples prepared in Examples 1-3 are tested by ellipsometer, and the results are shown in Figure 3 ; Figure 3 The refractive index curve spectrum of the titanium dioxide optical waveguide layer film prepared in Examples 1-3 is obtained by ellipsometer test; and Figure 3 It can be seen from the results that the refractive index of the titanium dioxide film prepared by different heat treatment temperatures varies. Compared with Examples 2 and 3, the refractive index gradually increases with the increase of the heat treatment temperature.

[0066] 3) The optical waveguide layer films prepared in Examples 1-3 are made into guided-mode resonance filters according to the conventional method, and the structure schematic diagram is shown in Figure 4 The control range of the optical waveguide layer films prepared in Examples 1-3 on the different resonance wavebands of the guided-mode resonance filter is calculated by using the rigorous coupled wave theory, and the results are shown in Figure 5 . Figure 5 The resonance waveband spectrum of the titanium dioxide optical waveguide layer film prepared in Examples 1-3 is shown in Figure 5 It can be seen from the results that the resonance waveband spectrum of the titanium dioxide optical waveguide layer film with different refractive indices varies. The resonance waveband reflectivity peak of the film prepared in Example 1 appears at 259nm, the resonance waveband reflectivity peak of the film prepared in Example 2 appears at 799nm, and the resonance waveband reflectivity peak of the film prepared in Example 3 appears at 1500nm, i.e. different refractive indices produce different resonance wavebands, and nearly 100% high reflectivity is produced.

[0067] 4) The optical waveguide layer film sample prepared in Example 2 is characterized by X-ray diffraction and scanning electron microscopy, and the results show that the film prepared in Example 2 is anatase titanium dioxide, and the surface of the film is smooth and has high density.​

[0068] 5) The optical waveguide layer film sample prepared in Example 3 was characterized by X-ray diffraction and scanning electron microscopy, and the results showed that the film prepared in Example 3 was anatase titanium dioxide, the film surface was smooth, and the density was high.

[0069] The above only describes the preferred embodiments of the present application, and it should be noted that those skilled in the art can make several improvements and refinements without departing from the principles of the present application, and these improvements and refinements should also be considered within the protection scope of the present application.

Claims

1. A method for producing an optical waveguide layer, characterized by, The method comprises the following steps: atomic layer deposition of a filter precursor source on a substrate under oxygen-containing conditions to obtain a deposited film; heat treatment of the deposited film to obtain an optical waveguide layer; the filter precursor source comprises tetrakis(dimethylamino)titanium, bis(tert-butylamino)silane, trimethylgallium or arsine; the substrate is a substrate with a periodic pattern on the surface, and the periodic pattern is prepared on the substrate by nanoimprint technology; the material of the substrate is quartz glass, silicon, anodized aluminum or an organic substance; the conditions of the atomic layer deposition include a deposition time of 20-200 h; the pulse time of the precursor source is 0.015-0.05 s, the pulse time of the oxygen source is 0.02-0.05 s, the inert gas flow is 5-50 sccm, the pressure in the deposition cavity is 20-100 Pa, the vacuum degree of the deposition cavity is <0.1 Pa, and the temperature of the substrate is 50-200 ℃; the thickness of the deposited film is 50-1000 nm; the temperature of the heat treatment is 150-450 ℃, and the time is 20-60 h; the optical waveguide layer is applied in a guided-mode resonance filter.

2. The production method according to claim 1, characterized by, the hole shape of the periodic pattern is a strip grating, a circle, a triangle, a rectangle or a polygon.

3. The preparation method according to claim 1, characterized in that, the oxygen source used in the oxygen-containing conditions comprises water or ozone.

4. The method of claim 1, wherein, the inert gas comprises nitrogen, argon or helium.

5. The optical waveguide layer prepared by the preparation method in any one of claims 1-4.

6. The application of the optical waveguide layer in claim 5 in a guided-mode resonance filter.

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