Far-infrared optical thin film window with medium wave infrared cut-off function

Abstract

The invention discloses a far-infrared optical thin film window with a medium wave infrared cut-off function. The optical thin film window takes lead telluride (PbTe) and cesium iodide (CsI) as high and low refractive index film materials, and is prepared by adopting a steam-resistant thermal evaporation deposition method to deposit a plurality of layers of films respectively at the two sides of a chemical vapor deposited (CVD) diamond substrate at the deposition temperature of 180+ / -2 DEG C in a vacuum environment with a pressure of (1-2)*10<-3>Pa; the far-infrared optical thin film window can realize the cut-off of light waves which are 5 microns away from the front of a medium-wave infrared ray; after the light waves are cut off, the average transmittance of the light waves is less than 0.5%, anti-reflection for light within a wave band of 5-50 microns is realized, and the average transmittance is greater than 76 .8%. The far-infrared optical thin film window can be applied to the fields such as deep space detection, far infrared object identification and earth radiation detection.

Description

technical field [0001] The invention relates to far-infrared band optical thin film technology, specifically a far-infrared optical thin-film window with mid-wave infrared cut-off function. By coating multi-layer films on CVD diamond, the transmission and neutralization of far-infrared band 5-50 microns can be realized. The cutoff of the wave-infrared pre-5 micron band. technical background [0002] As one of the basic key components of infrared remote sensing technology, infrared optical thin film filter has a direct impact on the performance of infrared remote sensing. The development of infrared optical thin film filters directly affects the development of infrared technology in military and civilian applications. The current mainstream infrared optical film filters are mainly researched in the band before 25 microns; for the infrared band after 25 microns, due to the limitation of optical film materials, there is little research on the direction of related optical films...

AI Technical Summary

Problems solved by technology

However, there is no special research on the detection of the 25-50 micron band interval, and it is only involved in the full-band detection.

This brings great difficulties to the study and analysis of long-wave channels.

[0005] In the research direction of the far-infrared window direction, some domestic organic substances such as polyethylene and plastics are used as window materials for infrared detectors in the 15-50 μm band. These materials are resistant to mechanical shocks, but they cannot respond to the spectrum before 15 μm. And the application of plastic polymer components in aerospace also has its shortcomings

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