阅读说明：本技术 一种用于产生180nm-290nm深紫外光的方法 (Method for generating 180nm-290nm deep ultraviolet light ) 是由 刘云俊 于 2020-07-16 设计创作，主要内容包括：本发明属于光电技术和医疗器械领域,具体涉及一种用于产生180nm-290nm深紫外光的方法,依次包括：激光器、准直镜、偏振风光棱镜、倍频晶体、四分之一波片和石英玻片,各元件的中心轴线对齐；所述偏振风光棱镜下方设有全反射镜。本发明通过调整输入光的偏振状态,将部分泄漏的圆偏振状态的输入光再次反射回光路中,进一步利用,从而实现输入光的最大化利用。(The invention belongs to the field of photoelectric technology and medical apparatus, and particularly relates to a method for generating 180nm-290nm deep ultraviolet light, which sequentially comprises the following steps: the device comprises a laser, a collimating mirror, a polarized wind-solar prism, a frequency doubling crystal, a quarter wave plate and a quartz slide, wherein the central axes of all elements are aligned; and a total reflection mirror is arranged below the polarization wind-light prism. The invention reflects part of the leaked input light with circular polarization state back to the light path for further utilization by adjusting the polarization state of the input light, thereby realizing the maximum utilization of the input light.)

1. A method for generating a deep ultraviolet light of 180nm to 290nm, comprising, in order: the device comprises a laser, a collimating mirror, a polarized wind-solar prism, a frequency doubling crystal, a quarter wave plate and a quartz slide, wherein the central axes of all elements are aligned; a total reflection mirror is arranged below the polarization wind-light prism;

(1) a laser with the wavelength of 380nm-580nm is used as a seed light source, and the generated laser is linearly polarized light;

(2) linearly polarized light vertically enters a polarization beam splitter prism after passing through a collimating mirror, then continuously propagates forwards to enter a frequency doubling crystal, and deep ultraviolet light with the wavelength of 180nm-290nm and a small amount of light with the wavelength of 380nm-580nm are output after frequency doubling, and the linearly polarized light is still the linearly polarized light at the moment;

(3) the light is continuously transmitted into the quarter-wave plate, and the linearly polarized light is converted into circularly polarized light;

(4) the light finally passes through a quartz glass slide, the rear end of the glass slide is coated with a film, the film has high reflection effect on light with a wave band of 380nm-580nm and has anti-reflection effect on deep ultraviolet light with a wave band of 180nm-290nm, namely: the deep ultraviolet light with the wave band of 180nm to 290nm generated by frequency doubling is output immediately, the light with the wave band of 380nm to 580nm is reflected and travels back, then the light passes through a quarter wave plate again, the part of circularly polarized light is changed into linearly polarized light, the linearly polarized light at the moment is vertical to the polarization direction of the initial linearly polarized light, then the linearly polarized light is transmitted through a collimating mirror for focusing, and then the linearly polarized light is incident into a polarized wind-solar prism again, because the polarization directions are different, the light at the moment cannot be transmitted back into a laser, but is reflected by 45 degrees and then is vertically incident on a total reflection mirror positioned below the total reflection mirror, then the light path is reversed, the part of light with the wave band of 380nm to 580nm enters a frequency doubling crystal.

2. The method for generating deep ultraviolet light of 180nm-290nm according to claim 1, wherein: the front and rear sections of the frequency doubling crystal are plated with antireflection films with wave bands of 380nm-580 nm.

3. The method for generating deep ultraviolet light of 180nm-290nm according to claim 1, wherein: the quartz glass coating material consists of two materials with refractive indexes selected from SiO₂/TiO₂，SiO₂/Ta₂O₅、Al₂O₃/ Ta₂O₅、MgF₂/Al₂O₃、ZnS/MgF₂。

Technical Field

The invention belongs to the field of photoelectric technology and medical instruments, and particularly relates to a method for generating deep ultraviolet light.

Background

The deep ultraviolet light, especially in UVC band (200-280 nm) and DUV band (40-200 nm), has the advantages of short wavelength, high resolution and the like, and is widely applied to the fields of medical disinfection, material processing, data storage and the like at present. The general ways of generating deep ultraviolet light can be divided into three categories: 1) the GaN-based compound semiconductor material is directly adopted to prepare a deep ultraviolet Light Emitting Diode (LED) and a Laser Diode (LD), but the electro-optic conversion efficiency is low, about 5%, the light output power is only a few milliwatts to tens of milliwatts, and the shorter the wavelength is, the difficulty in manufacturing the chip is increased; 2) the ArF excimer laser can generate deep ultraviolet rays with specific spectral bands of 157nm, 193nm and the like, but has the defects of fixed wave bands, toxic gas, high price and the like; 3) the all-solid-state deep ultraviolet light source can generate deep ultraviolet rays with wave bands below 200nm, and the deep ultraviolet rays are generated in a frequency doubling mode generally, but the all-solid-state deep ultraviolet light source has the disadvantages of large system volume, complex optical path inside the system, high price and the like.

CN103064228A (Timm Schmidton et al) discloses a method for realizing UVC band deep ultraviolet light output, which discusses that a 400-plus 560nm laser diode and a single crystal nonlinear optical material (BBO, KBBF, lithium pyroborate, rubidium lithium tetraborate) are combined to generate 200-plus 280nm deep ultraviolet light, but from the system structure diagram, after the 400-plus 560nm visible light passes through the frequency doubling system, a part of 400-plus 560nm visible light still exists in emergent light except the 200-plus 280nm deep ultraviolet light generated by frequency doubling, namely: the output light is not fully utilized, thereby causing a problem of low light conversion efficiency.

Disclosure of Invention

The invention aims to solve the problems of large system volume, fixed wave band, low light emitting efficiency, low frequency doubling efficiency and the like in the existing deep ultraviolet light generation system.

The invention reflects part of the leaked input light with circular polarization state back to the light path for further utilization by adjusting the polarization state of the input light, thereby realizing the maximum utilization of the input light.

The invention particularly discloses a method for generating 180nm-290nm deep ultraviolet light, which sequentially comprises a laser, a collimating mirror, a polarization wind-solar prism, a frequency doubling crystal, a quarter wave plate and a quartz slide, wherein the central axes of all elements are aligned; a total reflection mirror is arranged below the polarization wind-light prism; the light wavelength in the laser is 380nm-580 nm.

And the front section and the rear section of the frequency doubling crystal are both plated with antireflection films with wave bands of 380nm-580 nm.

The invention uses a laser with the wavelength of 380nm-580nm as a seed light source, the generated laser is linearly polarized light, after passing through a collimating mirror, the linearly polarized light is vertically incident to a polarization beam splitter Prism (PBS), then the linearly polarized light is continuously transmitted forwards to enter a frequency doubling crystal, antireflection films are plated on the front section and the rear section of the frequency doubling crystal, deep ultraviolet light with the wavelength of 180nm-290nm and a small amount of light with the wavelength of 380nm-580nm are output after frequency doubling, and the linearly polarized light is still generated at the moment. Then the light continuously transmits into the quarter wave plate, the linearly polarized light is converted into circularly polarized light, finally the circularly polarized light passes through a quartz glass slide, the rear end of the glass slide is coated with a film, the film has high reflection effect on the light with the wave band of 380nm-580nm, and has anti-reflection effect on the deep ultraviolet light with the wave band of 180nm-290nm, namely: the deep ultraviolet light with the wave band of 180nm to 290nm generated by frequency multiplication is output immediately, the light with the wave band of 380nm to 580nm is reflected and travels back, then the light passes through the quarter wave plate again, the part of circularly polarized light is changed into linearly polarized light, but the linearly polarized light at the moment is vertical to the polarization direction of the initial linearly polarized light, then the linearly polarized light is transmitted through the collimating mirror for focusing and then is incident into the PBS again, because the polarization directions are different, the light at the moment cannot be transmitted back into the laser, but is reflected by 45 degrees and then is vertically incident on the total reflecting mirror positioned below the total reflecting mirror, then the light path is reversed, the part of light with the wave band of 380nm to 580nm enters the frequency multiplication light path again, the frequency multiplication is continued, the deep ultraviolet light is output, and. Finally, frequency doubling output of the deep ultraviolet light with the wave band of 180nm-290nm is realized, output power is further improved, and maximum utilization of input optical power is realized.

The coating material for quartz slide of the invention generally consists of two materials with high and low refractive indexes, such as SiO₂/TiO₂，SiO₂/Ta₂O₅、Al₂O₃/ Ta₂O₅、MgF₂/Al₂O₃、ZnS/MgF₂And the like.

The technical scheme of the invention has the beneficial effects that:

(1) a Polarization Beam Splitter (PBS) is added in the light path, so that the transmission and the reflection of polarized light in different directions can be respectively realized; the linearly polarized light reflected by the PBS is vertically incident on the total reflection lens and then enters the frequency doubling optical path again after being reflected.

(2) In a frequency doubling light path, different polarization directions of input light are adjusted by introducing a lambda/4 slide, so that the input light after frequency doubling is output to the maximum, and the light output power is improved.

Drawings

Fig. 1 is a schematic structural diagram of a system according to an embodiment of the present invention.

In the figure: the device comprises a 1-laser, a 2-collimating mirror, a 3-polarization wind-solar prism, a 4-frequency doubling crystal, a 5-quarter wave plate, a 6-quartz slide, a 7-total reflection mirror, an 8-frequency doubling crystal antireflection film and a 9-quartz slide coating.

Detailed Description

The invention is further described below with reference to the accompanying drawings.