CN115373060B - Multichannel filter based on transmission type volume Bragg grating and preparation method thereof - Google Patents
Multichannel filter based on transmission type volume Bragg grating and preparation method thereof Download PDFInfo
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- G—PHYSICS
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Abstract
The invention discloses a multichannel filter based on a transmission type volume Bragg grating and a preparation method thereof, comprising the steps of preparing photothermal variable glass with a novel component, exposing the photothermal variable glass by utilizing an ultraviolet laser interference light path, designing a holographic exposure light path with an adjustable interference angle, conveniently changing the grating line direction and period of the volume Bragg grating, and simultaneously providing a spliced exposure scheme, manufacturing a large-caliber multichannel volume Bragg grating on the same photothermal variable glass and using the same as the multichannel filter; through the mode, the invention can realize wavelength and angle selection of light with various wavelengths by utilizing the one-piece Bragg grating, and effectively meets the application requirements of different scenes in the field of semiconductor laser.
Description
Technical Field
The invention relates to a filter technology in the field of laser transmission, in particular to a multichannel filter based on a transmission Bragg grating and a preparation method thereof.
Background
The optical filter is an important optical device in the field of optical wavelength division multiplexing, can be used for separating or filtering single-channel or multi-channel optical signals, and can be divided into a fixed optical filter and a tunable optical filter, and the main current optical filter comprises a dielectric film filter, a grating filter, an F-P cavity filter and the like.
The dielectric film filter uses the film plating sheet, the incident light can pass through the interference of the multi-layer dielectric films, other wavelengths can be prevented by a certain wavelength, the optical filtering is realized, the dielectric film filter is simple to manufacture, but the wavelength selection bandwidth is wider, the damage threshold is low, when the dielectric film filter is used as a multi-channel filter, a plurality of films are selected to be combined, and the system is complex; the grating filter uses the fiber grating, and the interference fringes are written in the doped fiber through ultraviolet exposure, so that the refractive index of the fiber is permanently changed along with the light intensity, the fiber grating has low insertion loss, simple structure, convenient fiber coupling and high wavelength selectivity, but the raw material development and writing process are complex and difficult; the F-P cavity filter has extremely high requirements on parallelism, roughness and surface quality of the reflector, and can influence the performance of the F-P filter; in a high-power laser system, the damage threshold of a required optical element is high, so that the optical element in a traditional filter is difficult to meet the requirement, and a novel optical material is required to be adopted to manufacture a spatial filter.
The transmission type Bragg grating based on photosensitive glass can also be used as a spatial filter, the medium-high frequency component in incident light does not meet Bragg conditions, the light passes through the body Bragg grating, the low frequency component meets Bragg conditions, and the light passes through the Bragg grating at a certain diffraction angle, so that angle filtering can be realized; compared with a common angle selection filter, the volume Bragg grating-based spatial filter also has the functions of compressing bandwidth and inhibiting side lobes, has more excellent filtering capability, is high in damage threshold value, can be used in a high-power laser system, is strong in designability, can realize different angle selectivities on the same volume Bragg grating, realizes a multi-channel filtering function, and is stronger in device functionality and better in integration level; in a semiconductor laser system, a beam deflector acts as a narrow-band mode selector in angles and spectrum space thereof, can realize spectrum selective beam control and angle selection, has high diffraction efficiency, long service life and good stability based on a transmission type Bragg grating of photo-thermal refraction glass, and can realize spectrum and angle selection of an incident beam.
However, the period and direction of the grating line of the single-block Bragg grating are fixed, only a single wavelength and angle selectivity are provided, and wavelength selection and angle control cannot be realized on light with multiple wavelengths; in order to manufacture the multi-channel filter, a plurality of volume bragg gratings are stacked for implementation, but the light energy utilization rate is low, the system is complex, and the application requirements in different scenes are difficult to meet, so that the prior art still needs to be improved and developed.
Disclosure of Invention
The invention mainly solves the technical problem of providing a multichannel filter based on a transmission type volume Bragg grating and a preparation method thereof, namely, the multichannel filter can realize wavelength and angle selection of light with various wavelengths through a volume Bragg grating, and effectively meets the application requirements of different scenes in the field of semiconductor laser.
In order to solve the technical problems, the invention adopts a technical scheme that: the multichannel filter comprises a photo-thermal refraction glass substrate, the number of channels, corresponding wavelengths and angles of the multichannel filter are required, the photo-thermal refraction glass substrate is correspondingly arranged and divided into a plurality of exposure areas, the exposure areas achieve the same exposure amount of different exposure areas through holographic exposure light paths with adjustable interference angles, and grating periods and grating line angles of the different exposure areas are different.
Preferably, the photothermographic element is formed by repeatedly smelting the following components: siO (SiO) 2 、B 2 O 3 、ZnO、Al 2 O 3 、ZrF 4 And Ag 2 CO 3 。
Preferably, the components of the photothermal conversion glass substrate correspond to the mass percentages of SiO respectively 2 10％～15％、B 2 O 3 18％～30％、ZnO 55％～60％、Al 2 O 3 5％～8％、ZrF 4 1％～5％、Ag 2 CO 3 0.01％～1％。。
The invention also provides a preparation method of the multichannel filter based on the transmission type volume Bragg grating, which comprises the following preparation steps:
(1) According to the required number n of channels of the multi-channel filter, n is an integer greater than or equal to 2, and the corresponding wavelength and angle selectivity, the arrangement mode of the exposure areas is designed according to the size of the photo-thermal refraction glass substrate, the grating period lambda and the grating line angle theta of the corresponding exposure areas are calculated, and the angles of interference beams under different exposure areas are calculated
(2) A black light barrier is arranged in front of the photo-thermal refraction glass substrate to cover other exposure areas, and only one exposure area is allowed to be exposed; utilizing a holographic exposure light path with adjustable interference angle to generate an interference light field which is arranged on the front surface of the photo-thermal refraction glass substrate and covers an exposure area to be exposed;
(3) When the holographic exposure light path exposes the first exposure area on the photothermographic substrate, the period of interference fringes in the interference light field and the period of writing the volume Bragg grating are both Λ 1 The grating line angle of the grating is theta 1 ；
(4) Changing the included angle of the interference light beam through the holographic exposure light path, exposing a second exposure area on the photothermographic refraction glass substrate according to the mode of the step (3), moving the black light barrier to enable the exposure area 2 to transmit light, wherein the exposure amount is the same as that of the first time, and the period of writing the volume Bragg grating is lambda 2 The grating line angle of the grating is theta 2 ；
(5) The same reason is that the exposure area n of the photothermographic glass substrate is exposed, the exposure amount is the same each time, and the period of writing the volume Bragg grating is Λ n The grating line angle of the grating is theta n ；
(6) After n times of exposure are completed, placing the whole photothermographic variable glass substrate into a heat treatment furnace for heat development and fixation;
(7) And continuously cutting, fine grinding, polishing and surface plating an antireflection film on the volume Bragg grating to finally obtain the multi-channel volume Bragg grating filter, namely a multi-channel filter product based on the transmission-type volume Bragg grating.
Preferably, the holographic exposure light path with adjustable interference angle includes an ultraviolet laser, a cube beam prism, an attenuation sheet, a first spatial filter, a second spatial filter, a first reflecting mirror, a second reflecting mirror, a first collimating lens, a second collimating lens and a substrate clamping frame, coherent light emitted by the ultraviolet laser passes through the cube beam prism and is divided into two beams of light in a reflection direction and a transmission direction, a light path in the transmission direction sequentially passes through the first reflecting mirror, the second spatial filter and the second collimating lens, a light path in the reflection direction sequentially passes through the attenuation sheet, the first spatial filter, the first collimating lens and the second reflecting mirror, and the two collimated parallel light mutually interfere to form parallel equidistant interference fringes in a light field at the rear.
Preferably, the first spatial filter and the second spatial filter are composed of a microscope objective and a pinhole filter, the aperture of the pinhole is in the order of micrometers, and the pinhole is placed at the focal position of the microscope objective.
Preferably, the first collimating lens and the second collimating lens are both aspheric lenses.
Preferably, the holographic exposure light path changes the interference included angle of two parallel beams by adjusting the deflection angle of the second reflecting mirror and the position of the substrate clamping frame, the period and the grating line direction of the grating can be adjusted, an electric turntable is arranged under the second reflecting mirror, the rotation angle of the electric turntable is driven by software to change the deflection of the beams, an electric six-dimensional displacement deflection table is arranged under the substrate clamping frame, and the relative position of the substrate and the interference light field is changed by driving the electric six-dimensional displacement deflection table by software.
Preferably, the attenuation sheet is an adjustable attenuation sheet, and the power of one of the two beams of laser is changed by adjusting the position of the attenuation sheet, so that the light intensities of two parallel beams of light which are interfered finally are kept consistent, and the contrast ratio of interference fringes is further improved.
Preferably, the temperature range between the thermal development and the fixing in the step (6) is 500 to 530 ℃.
The beneficial effects of the invention are as follows:
the invention discloses a multichannel filter based on a transmission Bragg grating and a preparation method thereof, comprising the steps of providing a photosensitive glass material system with a novel component, and preparing photo-thermal refraction glass by a multiple smelting method; the holographic exposure light path with adjustable interference angle is designed by utilizing an ultraviolet laser interference light path and double-beam exposure photothermographic refraction glass, the grating line direction and period of the volume Bragg grating can be conveniently changed, a spliced exposure mode is provided on the basis of the holographic exposure light path and the double-beam exposure photothermographic refraction glass, the large-caliber multichannel volume Bragg grating is manufactured and used as a space filter, different areas of the same volume photothermographic refraction glass are exposed, the photothermographic refraction glass after exposure is subjected to heat development and fixation, then the volume Bragg grating is subjected to fine grinding and polishing, and an antireflection film is plated on the rear surface, so that the volume Bragg grating filter with the large caliber and multiple channels can be finally obtained, different angle selectivities can be realized on the same volume Bragg grating, the multichannel filtering function is realized, the device has strong functionality, the integration level is good, and the designability is strong, and the technological popularization value is excellent.
Drawings
FIG. 1 is a schematic illustration of the position of an interference light field and a photo-thermal refractive glass according to the present invention, while showing the distribution of the exposure areas on the photo-thermal refractive glass;
FIG. 2 is a schematic diagram of a holographic exposure light path used in the present invention;
FIG. 3 is a graph of the angular versus wavelength selectivity of a transmissive bulk Bragg grating-based multichannel filter of the present invention, the relationship between the grating Bragg angle and the grating period when the wavelength λ of the incident light is the same;
FIG. 4 is a graph showing the relationship between the wavelength lambda of incident light and the period of the grating when the incident angle theta of the incident light is the same, based on the angle and the wavelength selectivity of the multi-channel filter of the transmission type volume Bragg grating according to the present invention;
the components in the drawings are marked as follows:
1. an ultraviolet laser; 2. a cube beam splitting prism; 3. a first mirror; 4. an attenuation sheet; 5. a first spatial filter; 6. a second spatial filter; 7. a first collimating lens; 8. a second collimating lens; 9. a second mirror; 10. a substrate clamping frame; 11. electric six-dimensional displacement deflection table.
Detailed Description
The following detailed description of the preferred embodiments of the invention is provided to enable those skilled in the art to more readily understand the advantages and features of the invention and to make a clear and concise definition of the scope of the invention.
Examples:
the invention provides a multichannel filter based on a transmission type volume Bragg grating and a preparation method thereof, comprising the steps of providing a novel photo-thermal refraction glass substrate formula, and preparing the novel photo-thermal refraction glass substrate by combining different components and smelting for multiple times; furthermore, a holographic exposure light path with an interference angle capable of being conveniently adjusted is designed, the grating line direction and period of the Bragg grating are conveniently changed, and on the basis of the light path, a spliced exposure scheme is further provided, and a large-caliber multichannel Bragg grating is manufactured and used as a filter, and specific technical information is as follows.
Firstly, photo-thermal refraction glass is a nonlinear optical phenomenon that the refractive index inside a glass material is changed due to the light intensity with uneven spatial distribution under the light radiation by utilizing the photo-refraction effect, and the manufacturing mode of the volume Bragg grating based on the photo-refraction material is as follows: the light intensity distribution of interference fringes with alternate brightness is recorded in the material, the refractive index of the interference fringes is changed, a refractive index modulation type phase grating is formed, and the recorded phase information can be fixed through a subsequent heat fixing process, so that long-time storage and information reading in the material are realized. Compared with other photosensitive materials such as silver salt, dichromated gelatin, photopolymer and the like, the volume Bragg grating based on the photothermographic refraction glass has good thermal stability and high damage threshold, and can be used in a high-power laser system.
The photothermographic element is prepared by repeatedly smelting the following components: siO (SiO) 2 、B 2 O 3 、ZnO、Al 2 O 3 、ZrF 4 And Ag 2 CO 3 . And the components of the photo and thermal sensitive refraction glass substrate correspond to the mass percentages of SiO respectively 2 10％～15％、B 2 O 3 18％～30％、ZnO 55％～60％、Al 2 O 3 5％～8％、ZrF 4 1％～5％、Ag 2 CO 3 0.01％～1％。
In the photo-thermal refraction glass formula system, ag is used 2 CO 3 Is a photosensitizer, and is exposed by ultraviolet light, ag+ is sensitized to form Ag atoms, the Ag atoms formed after sensitization and fluorine atoms formed by heat treatment are combined and polymerized into [ Ag 0F 0 ]]Micelle, zrF with similar induced crystal phase structure 4 Generation of primary crystalline phase by heat treatment of the exposed areas again to produce ZnSiO 3 Crystallization, resulting in an increase in refractive index of the exposed area,the unexposed area is kept in a glass state, crystallization does not occur, the refractive index does not change, the degree of the refractive index change changes along with the exposure dose, and thus 10 is generated in the exposed area and the unexposed area -3 The refractive index of the magnitude is changed, so that the photo-thermal refraction glass substrate can be manufactured by utilizing the mechanism and is used for manufacturing various microstructure patterns such as gratings, holograms and the like.
For the photo and thermal sensitive fold glass formulation system described above, the present invention provides at least two sets of embodiments, as follows:
| material | Proportion 1 | Proportion 2 |
| SiO 2 | 11.5％ | 11.4％ |
| B 2 O 3 | 19.2％ | 22.8％ |
| ZnO | 57.6％ | 55.0％ |
| Al 2 O 3 | 7.7% | 5.7% |
| ZrF 4 | 3.8% | 4.7％ |
| Ag 2 CO 3 | 0.2％ | 0.4％ |
Firstly, according to the number n of channels of a multi-channel filter (n is an integer greater than or equal to 2), the corresponding wavelength and angle selectivity, and the size of the photo-thermal refractive glass substrate prepared by the formula system, the photo-thermal refractive glass substrate is correspondingly arranged and divided into a plurality of exposure areas, the grating period lambda and the grating line angle theta of the corresponding exposure areas are calculated, and the angles of interference beams under different exposure areas are calculatedThe calculation modes are as follows:
if a certain channel in the designed volume Bragg grating filter uses a wavelength as input 1 The corresponding Bragg angle is theta 1 The required grating angle is θ, (λ) 1 ，θ，θ 1 All are known parameters, namely the requirement of a product) to calculate the corresponding channel lower body Bragg grating period as follows:where n is the refractive index of air. According to the calculated volume Bragg grating period lambda under different exposure areas n n The included angle of the interference beam in the exposure light path is: />
Step 2, a black light barrier is arranged in front of the photo-thermal refraction glass substrate to cover other exposure areas, and only one area is allowed to be exposed; an interference light field is generated by utilizing a holographic exposure light path with adjustable interference angle, and the interference light field is arranged on the front surface of the photo-thermal refraction glass substrate and covers an exposure area to be exposed. As shown in FIG. 1, the square is a large-caliber photo-thermal refraction glass substrate, the square area is divided into 9 equal proportion parts, the square areas are sequentially set into areas a-i from top to bottom, firstly, a black square light barrier is placed in front of the photo-thermal refraction glass to cover other areas, only the upper left corner area a is allowed to be exposed, an interference light field is generated by utilizing a holographic exposure light path with adjustable interference angle, a circle area in FIG. 1 is an interference light field area, and the interference light field is arranged on the front surface of the photo-thermal refraction glass substrate and covers the area a to be exposed.
As shown in fig. 2, the holographic exposure light path with adjustable interference angle includes an ultraviolet laser 1, a cube beam splitter prism 2, an attenuation sheet 4, a first spatial filter 5, a second spatial filter 6, a first reflecting mirror 3, a second reflecting mirror 9, a first collimating lens 7, a second collimating lens 8 and a substrate holding frame 10, the coherent light emitted by the ultraviolet laser 1 is split into two beams of light in a reflection direction and a transmission direction by the cube beam splitter prism 2, the light path in the transmission direction sequentially passes through the first reflecting mirror 3, the second spatial filter 6 and the second collimating lens 8, the light path in the reflection direction sequentially passes through the attenuation sheet 4, the first spatial filter 5, the first collimating lens 7 and the second reflecting mirror 9, and the two collimated parallel light beams interfere with each other to form parallel equidistant interference fringes in a light field at the rear.
As shown in fig. 2, in this process, the two-phase light passes through the first spatial filter 5 and the second spatial filter 6 and then becomes divergent spherical wave, further, the first spatial filter 5 and the second spatial filter 6 are composed of a microscope objective and a pinhole filter, the aperture of the pinhole is in the micrometer scale, and the pinhole is placed at the focal position of the microscope objective, so that various stray light can be effectively eliminated. The divergent spherical wave is changed into parallel light after passing through the first collimating lens 7 and the second collimating lens 8, the first collimating lens 7 and the second collimating lens 8 are aspheric lenses for reducing aberration of the parallel light as much as possible, the parallel light after passing through the first collimating lens 7 and the second collimating lens 8 is symmetrically distributed along the center of the substrate, and the grating equation 2dsin=λ is satisfied, wherein d is a period of interference fringes, λ is a wavelength of a coherent light source, and θ is half of an included angle of two incident parallel light beams.
As shown in fig. 2, the holographic exposure light path changes the interference included angle of two parallel beams by adjusting the deflection angle of the second reflecting mirror 9 and the position of the substrate clamping frame 10, so that the period and the grating line direction of the grating can be adjusted; further, an electric turntable (not shown in the figure) is arranged under the second reflecting mirror 9, the deflection of the light beam can be changed by driving the electric turntable to rotate through software, an electric six-dimensional displacement deflection table 11 is arranged under the substrate clamping frame 10, and the relative position of the substrate clamping frame 10 and the interference light field is changed by driving the electric six-dimensional displacement deflection table 11 through software; furthermore, the attenuation sheet 4 is an adjustable attenuation sheet, and the power of one of the two beams of laser is changed by adjusting the position of the attenuation sheet 4, so that the light intensities of two parallel beams of light which are interfered finally are kept consistent, and the contrast ratio of interference fringes is further improved.
In step 3 of the preparation method of the multi-channel filter based on the transmission type volume Bragg grating, when the holographic exposure light path exposes the first exposure area on the photothermographic refraction glass substrate, the period of interference fringes in the interference light field and the period of writing the volume Bragg grating are both Λ 1 The grating line direction of the grating is 0 degree relative to the substrate, and the included angle of the two interference lights is
After the exposure of the first exposure area is completed, the black light barrier is moved to enable the second area to transmit light, and the second reflecting mirror 9 is deflected by a certain angle through the electric turntableThe included angle of the interference light beam is theta 2 Wherein-> At this time grating periodThe position of the substrate clamping frame 10 is moved so that the deflected two light beams are still symmetrical relative to the photothermographic substrate, and the interference light field is on the front surface of the photothermographic substrate.
If the grating period still needs to be changed, the included angle of the two interference beams is continuously adjusted through the deflection of the second reflecting mirror 9; if the direction of the grating is only required to be changed, the angle of the photo and thermal refraction glass substrate is only required to be changed, namely, the geometrical center of the front surface of the photo and thermal refraction glass is rotated around the geometrical center by a certain angle, the relative position of the interference light field and the substrate can be changed, and therefore the direction of the grating recorded in the photo and thermal refraction glass is changed.
The same reason is that the nth exposure area of the photothermographic substrate is exposed, and the exposure amount is the same every time, and the period of the written volume Bragg grating is Λ n The included angle of the interference light beam is theta n In the embodiment, the grating period and angle of each region are sequentially defined as a region a according to the region division shown in fig. 1: Λ type a 0; region b: Λ type b 0; region c: Λ type c 0; region d: Λ type a θ; region e: Λ type b θ; region f: Λ type c θ; region g: Λ type a - θ; region h: Λ type b - θ; region i: Λ type c ，-θ。
After n times of exposure are completed, placing the whole photothermographic glass substrate into a heat treatment furnace for heat development and fixation for a period of time, wherein the temperature interval between the heat development and fixation is preferably 500-530 ℃, continuously cutting, fine grinding, polishing and surface plating an antireflection film on the volume Bragg grating, and finally obtaining the volume Bragg grating filter with large caliber and multiple channels, namely a multi-channel filter product based on the transmission-type volume Bragg grating.
The multi-channel Bragg grating manufactured by the spliced exposure mode can realize the functions of a plurality of transmission type gratings on the same device, namely, the Bragg diffraction angles of different areas are different for the incidence of light with the same wavelength, the body Bragg grating has a plurality of angle selectivities,the bragg angles of the different regions are:where en is the tilt angle of the grating lines, lambda is the wavelength of the incident light, n 0 For air index, Λn is the period of the grating.
For the same incident light wave, grating periods in different areas are different, and the Bragg angles are also different, so that multi-angle selection can be realized; for the multi-wavelength light beam, the wavelength selectivity of different areas of the grating is different under the same incidence angle, the specific area of the grating can only pass through specific wavelengths, the wavelength selection bandwidth can be realized, the smaller the period is, the smaller the wavelength selection bandwidth is, and the multi-channel high-precision filter can be used, wherein the incidence angle and the wavelength selectivity are respectively shown in fig. 3 and 4.
The invention utilizes self-made novel photo-thermal refraction glass, writes different grating periods and grating angles into specific areas respectively through a splicing exposure scheme, then makes a multichannel spatial filter through subsequent procedures such as heat treatment and the like, designs a multichannel area and grating periods and grating line angles according to different requirements, can realize different angle selectivities on the same piece of Bragg grating, realizes a multichannel filtering function, and has stronger device functionality and better integration level.
The foregoing description is only illustrative of the present invention and is not intended to limit the scope of the invention, and all equivalent structures or equivalent processes or direct or indirect application in other related arts are included in the scope of the present invention.
Claims (7)
1. A preparation method of a multichannel filter based on a transmission type volume Bragg grating is characterized by comprising the following steps: the multi-channel filter comprises a photo-thermal refraction glass substrate, wherein the photo-thermal refraction glass substrate is correspondingly arranged and divided into a plurality of exposure areas according to the number of channels, corresponding wavelengths and angles of the multi-channel filter, the exposure areas realize the same exposure amount of different exposure areas through holographic exposure light paths with adjustable interference angles, and the grating periods and grating line angles of the different exposure areas are different;
the photothermographic element is formed by repeatedly smelting the following components: siO (SiO) 2 、B 2 O 3 、ZnO、Al 2 O 3 、ZrF 4 And Ag 2 CO 3 The method comprises the steps of carrying out a first treatment on the surface of the The corresponding mass percentages are respectively SiO 2 10%~15%、B 2 O 3 18%~30%、ZnO 55%~60%、Al 2 O 3 5%~8%、ZrF 4 1%~5%、Ag 2 CO 3 0.01%~1%；
The preparation method of the multichannel filter based on the transmission type volume Bragg grating comprises the following preparation steps:
(1) According to the required number n of channels of the multi-channel filter, n is an integer greater than or equal to 2, and the corresponding wavelength and angle selectivity, designing an arrangement mode of an exposure area according to the size of a photo-thermal refraction glass substrate, calculating a grating period lambda and a grating line angle theta of the corresponding exposure area, and simultaneously calculating the angle phi of an interference light beam under different exposure areas;
(2) A black light barrier is arranged in front of the photo-thermal refraction glass substrate to cover other exposure areas, and only one exposure area is allowed to be exposed; utilizing a holographic exposure light path with adjustable interference angle to generate an interference light field which is arranged on the front surface of the photo-thermal refraction glass substrate and covers an exposure area to be exposed;
(3) When the holographic exposure light path exposes the first exposure region on the photothermographic substrate, the period of interference fringes in the interference light field and the period of writing the volume Bragg grating are both Λ 1 The grating line angle of the grating is theta 1 ；
(4) Changing the interference beam angle by holographic exposure light path, exposing the second exposure area on the photothermographic refraction glass substrate according to the method of the step (3), and moving the black light barrier so that only the second oneThe exposure area is transparent, the exposure amount is the same as that of the first time, and the period of the written volume Bragg grating is lambda 2 The grating line angle of the grating is theta 2 ；
(5) The same reason is that the exposure area n of the photothermographic glass substrate is exposed, the exposure amount is the same each time, and the period of writing the volume Bragg grating is Λ n The grating line angle of the grating is theta n ；
(6) After n times of exposure are completed, placing the whole photothermographic variable glass substrate into a heat treatment furnace for heat development and fixation;
(7) And continuously cutting, fine grinding, polishing and surface plating an antireflection film on the volume Bragg grating to finally obtain the multi-channel volume Bragg grating filter, namely a multi-channel filter product based on the transmission-type volume Bragg grating.
2. The method for preparing the multichannel filter based on the transmission type volume Bragg grating according to claim 1, wherein the method comprises the following steps: the holographic exposure light path with adjustable interference angle comprises an ultraviolet laser, a cube beam prism, an attenuation sheet, a first spatial filter, a second spatial filter, a first reflecting mirror, a second reflecting mirror, a first collimating lens, a second collimating lens and a substrate clamping frame, coherent light emitted by the ultraviolet laser is divided into two beams of light in a reflection direction and a transmission direction through the cube beam prism, a light path in the transmission direction sequentially passes through the first reflecting mirror, the second spatial filter and the second collimating lens, a light path in the reflection direction sequentially passes through the attenuation sheet, the first spatial filter, the first collimating lens and the second reflecting mirror, and parallel light after two collimated beams mutually interfere to form parallel equidistant interference fringes in a light field at the rear.
3. The method for preparing the multichannel filter based on the transmission type volume bragg grating according to claim 2, wherein the method comprises the following steps: the first spatial filter and the second spatial filter are composed of a microscope objective and a pinhole filter, the aperture of a pinhole is in the micron order, and the pinhole is placed at the focal position of the microscope objective.
4. The method for preparing the multichannel filter based on the transmission type volume bragg grating according to claim 2, wherein the method comprises the following steps: the first collimating lens and the second collimating lens are aspheric lenses.
5. The method for preparing the multichannel filter based on the transmission type volume bragg grating according to claim 2, wherein the method comprises the following steps: the holographic exposure light path changes the interference included angle of two parallel beams by adjusting the deflection angle of the second reflecting mirror and the position of the substrate clamping frame, the period and the grating line direction of the grating can be adjusted, an electric turntable is arranged under the second reflecting mirror, the deflection of the beams is changed by driving the electric turntable to rotate by software, an electric six-dimensional displacement deflection table is arranged under the substrate clamping frame, and the relative position of the substrate and the interference light field is changed by driving the electric six-dimensional displacement deflection table by software.
6. The method for preparing the multichannel filter based on the transmission type volume bragg grating according to claim 2, wherein the method comprises the following steps: the attenuation sheet is an adjustable attenuation sheet, and the power of one of the two beams of laser is changed by adjusting the position of the attenuation sheet, so that the light intensities of two parallel beams of light which are interfered finally are consistent, and the contrast ratio of interference fringes is further improved.
7. The method for preparing the multichannel filter based on the transmission type volume Bragg grating according to claim 1, wherein the method comprises the following steps: the temperature interval between the thermal development and the fixation in the step (6) is 500-530 ℃.
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Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS569243A (en) * | 1979-06-30 | 1981-01-30 | Hoya Corp | Laser glass having small induction emitting cross-sectional area and low nonlinear refractive index factor |
| JP2005247921A (en) * | 2004-03-02 | 2005-09-15 | Chisso Corp | Liquid crystal composition containing microparticle and liquid crystal display element using the same |
| CN105792951A (en) * | 2013-12-03 | 2016-07-20 | 西门子能源公司 | Flux assisted laser removal of thermal barrier coating |
| CN108761602A (en) * | 2018-05-22 | 2018-11-06 | 苏州大学 | The autocollimatic adjusting method of optical interference circuit in a kind of holographic grating lithography system |
| CN111977973A (en) * | 2020-07-06 | 2020-11-24 | 天津全和诚科技有限责任公司 | Preparation method of photo-thermal sensitive material |
| CN214225472U (en) * | 2021-01-26 | 2021-09-17 | 深圳惠牛科技有限公司 | Volume holographic grating and preparation system, replication processing structure and waveguide structure thereof |
| CN113805454A (en) * | 2021-10-29 | 2021-12-17 | 绍兴钜光光电科技有限公司 | Scattered light field holographic three-dimensional displacement measuring device, method and medium |
| CN113904213A (en) * | 2021-12-08 | 2022-01-07 | 杭州拓致光电科技有限公司 | Multi-wavelength wave locker based on photo-thermal conversion glass and preparation method thereof |
-
2022
- 2022-07-22 CN CN202210866740.8A patent/CN115373060B/en active Active
Patent Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS569243A (en) * | 1979-06-30 | 1981-01-30 | Hoya Corp | Laser glass having small induction emitting cross-sectional area and low nonlinear refractive index factor |
| JP2005247921A (en) * | 2004-03-02 | 2005-09-15 | Chisso Corp | Liquid crystal composition containing microparticle and liquid crystal display element using the same |
| CN105792951A (en) * | 2013-12-03 | 2016-07-20 | 西门子能源公司 | Flux assisted laser removal of thermal barrier coating |
| CN108761602A (en) * | 2018-05-22 | 2018-11-06 | 苏州大学 | The autocollimatic adjusting method of optical interference circuit in a kind of holographic grating lithography system |
| CN111977973A (en) * | 2020-07-06 | 2020-11-24 | 天津全和诚科技有限责任公司 | Preparation method of photo-thermal sensitive material |
| CN214225472U (en) * | 2021-01-26 | 2021-09-17 | 深圳惠牛科技有限公司 | Volume holographic grating and preparation system, replication processing structure and waveguide structure thereof |
| CN113805454A (en) * | 2021-10-29 | 2021-12-17 | 绍兴钜光光电科技有限公司 | Scattered light field holographic three-dimensional displacement measuring device, method and medium |
| CN113904213A (en) * | 2021-12-08 | 2022-01-07 | 杭州拓致光电科技有限公司 | Multi-wavelength wave locker based on photo-thermal conversion glass and preparation method thereof |
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