Alpha-BBO polarizing prism

Abstract

The invention relates to an alpha-barium boron oxide (alpha-BBO) polarizing prism. During material selection, a crystalline material, namely LiF crystals with the highest vacuum ultraviolet-far infrared transmittance, the best ultraviolet-far infrared crystalline materials, namely alpha-BBO crystals, for making a polarizing prism, and LiF crystals with extremely low refractive index are particularly selected. During design, a cuboid hamburger structure connected by two alpha-BBO crystal prisms and a piece of LiF window optical cement is adopted, a light path is completely glue-free, the transmittance is high, the vertex angles of the two alpha-BBO crystal prisms are 57.8+ / -0.2 degrees, an optical axis of the alpha-BBO polarizing prism is vertical to an o-light spilling plane, the o-light is totally spilt from the side face, the volume is small, the wavelength coverage range is between 0.19 and 3.5 mu m, the total incident angle of the o-light and e-light is more than 11 degrees in the whole wavelength range, the extinction ratio is less than 5*10<-6>, and the transmittance is high.

Description

【Technical field】 [0001] The invention belongs to the field of structural design and material selection of optical elements, and in particular relates to an α-BBO polarizer. 【technical background】 [0002] With the rapid development of ultraviolet optical technology, especially ultraviolet and deep ultraviolet testing and processing instruments, ultraviolet polarizing devices have always been the object of people's attention. It is one of the core components of some ultraviolet testing and processing instruments, such as ultraviolet-visible light spectrophotometry , ellipsometer, etc. [0003] At present, in the optical field of the visible and near-infrared spectral ranges, the polarizing prisms generally used are Glan laser, Glan Taylor or Glan Thomson prisms made of Iceland stone crystals, but Iceland stone is natural, and the internal The quality and source of materials have become the key factors affecting the production of polarizing devices; the applicable wavelength...

AI Technical Summary

Problems solved by technology

[0003] At present, in the optical field of the visible and near-infrared spectral ranges, the polarizing prisms generally used are Glan laser, Glan Taylor or Glan Thomson prisms made of Iceland stone crystals, but Iceland stone is natural, and the internal The quality and source of materials have become the key factors affecting the production of polarizing devices; the applicable wavelength range of icelandite polarizers is 350-2300nm, and cannot be applied to ultraviolet light; moreover, icelandite crystals are rhombohedral, and the requirements for the optical axis of polarizers make crystals Low utilization rate, easy processing and cleavage, low hardness is not suitable for polishing and other processing

[0004] In addition, the currently applicable visible to mid-infrared polarizer is YVO 4 Fabricated Air-Spaced Glan Laser Prism, YVO 4 The crystal has good optical uniformity, is easy to process, and is easy to generate. However, like the icelandite polarizing prism, the ultraviolet band is not applicable

[0005] Currently used to make polarizing materials for ultraviolet, visible and near-infrared, α-BBO crystals are generally used, and the connection method is glue or air gap connection. These two combinations have obvious disadvantages: ① Disadvantages of glue connection: the glue itself passes through the wavelength band It is very narrow and absorbs a lot, especially the ultraviolet absorption is very strong. There has never been a good wide-band glue with small ultraviolet absorption; ② Disadvantages of air gap connection: α-BBO Glan laser polarizing prism made , the applicable wavelength band is very narrow (near 100nm), the incident angle is very small, and the extinction ratio is not good

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