Method for making rectangular deep cut-off ultra-narrow band pass filter

Abstract

The invention provides a method for making deep cut-off ultra-narrow band pass filter. By adopting the method, the effective area and the cut-off of the bandpass filter can be obviously improved and error negative effects can be effectively controlled. The method comprises the following steps of: 1, determining a theoretical film, selecting Ta2O5 as a high-reflectivity material and SiO2 as a low-reflectivity material on the basis of a typical film structure of a multi-cavity optical filter, respectively defining H and L to be the unit optical thickness of the Ta2O5 and the SiO2 on lambda fourth by taking lambda as an operating wavelength of the optical filter, and determining the film structure of the optical filter by using film design software thin film circuit (TFC) Calc on a computer according to performance parameters required by the ultra-narrow band pass filter; 2, making a template control file for automatic control of a coating machine by using the full-automatic coating machine according to the obtained theoretical film structure; and 3, loading selected coating materials in the coating machine and automatically completing the making of the optical filter through a control mode of eccentric monitoring by the coating machine according to a selected template.

Description

technical field [0001] The invention relates to an ultra-narrow band pass filter which is mainly used for a 1.06 micron laser and its application system and has high pass band rectangularity and forbidden band deep cut-off performance. Background technique [0002] Laser has four optical properties of isotropy, high brightness, monochromaticity and high energy density. Due to its special characteristics relative to ordinary light, lasers and their application systems have played an increasingly important role in the development of modern society, and are widely used in various civil and military fields. In the optical system of the laser and its application system, in order to meet the system design requirements, the optical components that the optical path passes through in the system generally need to be coated with optical films. [0003] The so-called optical thin film refers to the selection of coating materials with different optical refractive indices, and the use of...

AI Technical Summary

Problems solved by technology

After the spectrum of a single-cavity filter drifts with temperature, the transmittance at the working wavelength may change greatly, which is not conducive to the stability of the work

[0011] 2. Poor cut-off

Especially for the multi-cavity filter, which is a precision thin film that is extremely sensitive to control errors, a little carelessness in the coating process is very likely to affect each other between the multi-cavities, resulting in the deformation of the passband of the obtained product or even collapse and become a waste product.

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