阅读说明：本技术 一种微窄条带滤光片的制备方法 (Preparation method of micro-strip optical filter ) 是由 鱼卫星 郭权 武登山 于 2021-07-22 设计创作，主要内容包括：本发明公开了一种微窄条带滤光片的制备方法,解决了现有技术微窄条带滤光片膜片破损、边缘粗糙度大的问题,包括以下步骤：一、基底熔蚀:取玻璃基底,利用激光诱导等离子体在玻璃基底表面刻蚀垂直槽；二、滤光膜层蒸镀：对玻璃基底上刻蚀的垂直槽蒸镀滤光膜层,滤光膜层厚度＜垂直槽深度；三、玻璃基底底面减薄：将镀有滤光膜的一面粘接到抛光盘上,用光学玻璃研磨机对玻璃基底底面研磨和抛光,直至玻璃基底厚度接近设定值；四、玻璃基底切割：利用激光切割机从底面对减薄的玻璃基底进行切割,沿垂直槽边界处切割；五、玻璃基底裂片释放：利用裂片机对进行切割后的玻璃基底进行裂片释放,保留相邻的垂直槽之间的部分即构成微窄条带滤光片。(The invention discloses a preparation method of a micro strip filter, which solves the problems of breakage and large edge roughness of a micro strip filter membrane in the prior art, and comprises the following steps: firstly, substrate ablation, namely taking a glass substrate, and etching a vertical groove on the surface of the glass substrate by utilizing laser-induced plasma; secondly, evaporating the light filtering film layer: evaporating a light filtering film layer on a vertical groove etched on a glass substrate, wherein the thickness of the light filtering film layer is less than the depth of the vertical groove; thinning the bottom surface of the glass substrate: adhering the surface plated with the filter film to a polishing disk, and grinding and polishing the bottom surface of the glass substrate by using an optical glass grinder until the thickness of the glass substrate is close to a set value; fourthly, cutting the glass substrate: cutting the thinned glass substrate from the bottom surface by using a laser cutting machine, and cutting along the boundary of the vertical groove; fifthly, glass substrate splinter release: and (4) splitting and releasing the cut glass substrate by using a splitting machine, and reserving the part between the adjacent vertical grooves to form the micro strip filter.)

1. A method for manufacturing a micro-strip filter is characterized in that: the method comprises the following steps:

step one, substrate ablation

Taking a glass substrate, and etching a vertical groove on the surface of the glass substrate by utilizing laser-induced plasma;

step two, evaporating the light filtering film layer

Carrying out evaporation coating of a light filtering film layer on a vertical groove etched on a glass substrate, wherein the thickness of the light filtering film layer is less than the depth of the vertical groove;

step three, thinning the bottom surface of the glass substrate

Adhering the surface plated with the filter film to a polishing disk, and grinding and polishing the bottom surface of the glass substrate by using an optical glass grinder until the thickness of the glass substrate is close to a set value;

step four, cutting the glass substrate

Cutting the thinned glass substrate from the bottom surface by using a laser cutting machine, wherein the cutting position is the position of the boundary of the vertical groove;

step five, glass substrate splinter release

And splitting and releasing the cut glass substrate by using a splitting machine, removing the part corresponding to the vertical groove, and taking the rest part as the micro strip optical filter.

2. The method of manufacturing a microstrip strip filter according to claim 1 wherein: in step three, the set value is 100 μm. + -. 5 μm.

3. A method for manufacturing a microstrip strip filter as claimed in claim 2, wherein: in the first step, the glass substrate is quartz glass, and the thickness of the quartz glass is 0.5-1 mm.

4. A method for manufacturing a microstrip band filter according to claim 3 wherein: in the first step, the width of the vertical slots is 0.1mm, the depth is 30-50um, and the interval between the adjacent vertical slots is 0.05-0.1 mm.

5. A method for manufacturing a microstrip band filter according to claim 3 wherein: in the third step, the surface coated with the light filtering film is adhered to a polishing disk by paraffin.

6. The method of manufacturing a microstrip strip filter according to claim 1 wherein: in the second step, the evaporated filter film layer structure is Fabry-Perot (F-P).

Technical Field

The invention relates to a preparation method of a micro-strip optical filter.

Background

A spectrometer, also known as a spectrometer, is a scientific instrument that decomposes light with complex components into spectral lines. The light splitting technology is one of core technologies in a spectrum instrument, and is widely applied to military and civil fields such as scientific research and teaching, environmental monitoring, biomedicine, scientific and technological agriculture, industrial process monitoring and the like. In order to adapt to large-scale industrial application, the existing spectrometer is always close to the direction of meeting the requirements of light weight, microminiaturization, low cost, portability and the like, and the requirements promote the development of the spectrometer to the direction of highly concentrating components and activating light on an area array detector; the spectral imaging chip technology can greatly simplify the design of a spectral imaging instrument, the principle is that a conventional multispectral separation system is miniaturized and is directly integrated on the surface of an image sensor, and the structure of the multispectral imaging chip is different from that of a common optical camera only in that the image sensor is replaced by the spectral imaging chip, so that the aim of multispectral imaging can be fulfilled, and the volume of the spectral imaging instrument is greatly reduced. The novel spectrometer is characterized in that micro-strip filters with different central wavelengths are spliced and integrated on a target surface of an area array detector to form a filtering module, so that on-chip light splitting is realized to perform spectral imaging.

The existing preparation method of the micro-narrow band optical filter generally adopts the modes of Diamond knife cutting (Diamond scriber), laser cutting, invisible cutting (SD) and metal wire cutting to realize the separation of the optical filter strip, but the roughness of the edge of the micro-narrow band optical filter prepared by the Diamond knife cutting and metal wire cutting modes is large (more than 30um), and the requirement of a miniaturized optical filter module on the low roughness of the edge of the micro-narrow band optical filter cannot be met; laser cutting and invisible cutting can only penetrate through the optical filter with specific central wavelength, and the substrate (glass/sapphire) cannot be completely split on the basis of complete cutting (as shown in figure 1), so that the film layer is seriously damaged, and the pixel utilization rate of the detector is extremely low.

Disclosure of Invention

The invention provides a preparation method of a micro-strip band filter, which can solve the problems of breakage and large edge roughness of a micro-strip band filter membrane in the prior art.

A method for preparing a micro-strip filter is characterized in that: the method comprises the following steps:

step one, substrate ablation

Taking a glass substrate, and etching a vertical groove on the surface of the glass substrate by utilizing laser-induced plasma;

step two, evaporating the light filtering film layer

Carrying out evaporation coating of a light filtering film layer on a vertical groove etched on a glass substrate, wherein the thickness of the light filtering film layer is less than the depth of the vertical groove;

step three, thinning the bottom surface of the glass substrate

Adhering the surface plated with the filter film to a polishing disk, and grinding and polishing the bottom surface of the glass substrate by using an optical glass grinder until the thickness of the glass substrate is close to a set value;

step four, cutting the glass substrate

Cutting the thinned glass substrate from the bottom surface by using a laser cutting machine, wherein the cutting position is the position of the boundary of the vertical groove;

step five, glass substrate splinter release

And splitting and releasing the cut glass substrate by using a splitting machine, removing the part corresponding to the vertical groove, and taking the rest part as the micro strip optical filter.

Further, in step three, the set value is 100 μm. + -. 5 μm.

Further, in the first step, the glass substrate is quartz glass, and the thickness of the quartz glass is 1 mm.

Further, in the first step, the width of the vertical slots is 0.1mm, the depth is 30-50um, and the interval between the adjacent vertical slots is 0.1 mm.

Further, in the third step, the side coated with the light filter film is adhered to the polishing disk by using paraffin.

Further, in the second step, the filtering film layer is a Fabry-Perot (F-P) structure after evaporation.

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

due to the shadow effect, when the light filtering film layer is evaporated, the light filtering film layer is not arranged at the boundary of the vertical groove, the strip separation of the micro strip light filter can be completed by cutting through the glass substrate along the boundary of the vertical groove, the situation that the film layer is damaged after splitting due to the fact that laser cannot penetrate through the film layer for cutting during cutting is avoided, and the completeness of the light filtering film layer can be guaranteed; the micro-strip band filter prepared by the invention has small strip edge roughness (less than 2um), and meets the requirement of a miniaturized filtering module on low roughness of the edge of the micro-strip band filter.

Drawings

FIG. 1 is a schematic view of an edge of a micro-strip filter prepared by laser cutting and invisible cutting;

FIG. 2 is a schematic diagram of a first step of the present invention;

FIG. 3 is a schematic perspective view of a vertical slot in step one according to an embodiment of the present invention;

FIG. 4 is a schematic side view of a vertical slot in step one according to an embodiment of the present invention;

FIG. 5 is a schematic perspective view of a vertical slot in step two according to the embodiment of the present invention;

FIG. 6 is a schematic side view of a vertical slot in step two according to the embodiment of the present invention;

FIG. 7 is a schematic perspective view of a vertical trench in step three according to an embodiment of the present invention;

FIG. 8 is a schematic side view of a vertical trench in step three according to an embodiment of the present invention;

FIG. 9 is a diagram illustrating step four according to the present invention;

FIG. 10 is a diagram illustrating a fifth step in accordance with the present invention.

Detailed Description

The following detailed description of the present invention is provided in conjunction with the accompanying drawings, but it should be understood that the scope of the present invention is not limited to the specific embodiments.

Step one, substrate ablation

Taking a glass substrate, wherein the glass substrate is quartz glass with the thickness of 1mm, and etching a vertical groove on the surface of the glass substrate by utilizing laser-induced plasma, as shown in fig. 3 and 4, the width of the vertical groove is 0.1mm, the depth of the vertical groove is 50um, and the interval between the adjacent vertical grooves is 0.1 mm; as shown in FIG. 2, a carbon dioxide laser is used, and the generated laser passes through an expansion mirror, a reflector and a focusing mirror in sequence, and then a vertical groove is etched on the surface of the glass substrate.

Step two, evaporating the light filtering film layer

Performing evaporation coating of a light filtering film layer on a vertical groove etched on a glass substrate, wherein the thickness of the light filtering film layer is less than the depth of the vertical groove, as shown in fig. 5 and 6, the thickness of the light filtering film layer in the groove and the thickness of the surface of a region without the groove are both 10um, and due to the influence of a shadow effect, a semi-blind region is formed at the bottom surface of the vertical groove close to the side wall of the vertical groove during evaporation coating of the light filtering film layer, as shown in a shadow part shown in fig. 8, and the width of the shadow part reaches 30 um; in addition, the larger the depth of the vertical groove is, the larger the area of the bottom surface of the vertical groove in the semi-blind area is, and the glass substrate can be cut more conveniently; but also increases the difficulty of the thinning process, so that the depth of the vertical groove is less than or equal to 50um in the actual preparation process;

the filter film layer after evaporation is of a Fabry-Perot (F-P) structure, taking a narrow-band filter with the center wavelength of 740nm as an example, the specific structure of the film layer is Air/HLHLHLHLHLHLH2.512LHLHLHLHLHLHLH/Sub; the meaning of the membrane system symbols are respectively: air, Sub, substrate, H and L represent one λ 0/4 wavelength optical thickness of the high refractive index material film layer and the low refractive index material film layer, respectively, λ 0 is the center wavelength of the microstrip strip filter, and λ 0 is 740 nm.

Step three, thinning the bottom surface of the glass substrate

Adhering the surface plated with the light filtering film to a polishing disk by adopting paraffin, and grinding and polishing the bottom surface of the glass substrate by using an optical glass grinder as shown in figure 7 until the thickness of the glass substrate is close to a set value of 100 mu m +/-5 mu m;

step four, cutting the glass substrate

The thinned glass substrate may be cut from the bottom surface using a carbon dioxide laser, or 532nm femtosecond laser in step one, at the vertical slot boundaries, as shown in fig. 9;

step five, glass substrate splinter release

The glass substrate after cutting is subjected to splitting release by a splitting machine, the portion corresponding to the vertical groove is removed, and the remaining portion is the micro strip filter, as shown in fig. 10.

The above disclosure is only for the specific embodiment of the present invention, but the embodiment of the present invention is not limited thereto, and any variations that can be made by those skilled in the art should fall within the scope of the present invention.