Ultra-smooth dual-band mirror and its preparation method

Abstract

The invention provides an ultra-smooth dual-band reflector and a preparation method thereof, wherein the ultra-smooth dual-band reflector includes a substrate and a reflective film plated on the substrate, and the reflective film is composed of alternately laminated platinum films and non-metallic films , the metal film includes a chromium film and a platinum film, the chromium film is plated on the substrate, the platinum film and the non-metal film are alternately laminated and plated on the chromium film, and the top layer and the bottom layer in the laminated structure formed by the platinum film and the non-metal film are both It is a chromium film, the thickness of the chromium film is 1-3nm, the thickness of each platinum film is 5-30nm, the thickness of each non-metallic film is 1-100nm, and the total thickness of the reflective film is 100-300nm. The invention can ensure low high-frequency roughness and intermediate-frequency roughness, and at the same time, has high reflectivity for imaging bands, and has strong resistance to space environment radiation, good space adaptability and stable performance.

Description

technical field [0001] The invention relates to the technical field of reflecting mirrors, in particular to an ultra-smooth dual-band reflecting mirror and a preparation method thereof. Background technique [0002] In coronal imaging detection, since the light intensity on the solar surface is much higher than the coronal light intensity, stray light suppression is the focus and difficulty in the development of coronagraphs. At present, there are mainly two kinds of coronal imaging optical systems: internal cover type and external cover type. The main mirror in the built-in imaging optical system directly faces the sunlight, and its scattering is the main source of stray light. Therefore, in addition to requiring the main reflector to have high reflectivity in the imaging band (121.6nm and visible light band), the main reflector is also required to have an ultra-smooth surface (roughness better than 0.3nm). To get an ultra-smooth mirror, you first need an ultra-smooth sub...

AI Technical Summary

Problems solved by technology

[0004] The SCORE coronal observation payload developed in Italy uses a Mo / Si multi-layer mirror with a high-frequency roughness of about 0.5nm, which will cause severe large-angle scattering; the reflectivity in the visible light band is low, and the absorption rate is 57%. Left and right, in the case of direct sunlight, the lens temperature will exceed 50°C, which will cause the lens surface to deteriorate; no matter whether the last layer of the Mo / Si multilayer mirror is Mo or Si, in the harsh space environment (atomic Oxygen, high-energy protons, electrons, high-energy rays, ultraviolet light), the oxidation of the film layer will occur, resulting in a decrease in the reflectivity at 121.6nm

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