Cold diaphragm with light blocking ring structure

Abstract

The invention discloses a cold diaphragm with a light blocking ring structure. The invention is characterized in that two light blocking rings are reasonably added into the internal wall of the cold diaphragm, and the surfaces of the light blocking rings are coated with a layer of black coating with excellent performance, thus effectively reducing stray light. The design can excellently improve the signal-to-noise ratio of the system, enhances the contrast ratio and improves the exploring and recognizing capacities of the whole system. Compared with cold diaphragms without the light blocking ring structure, the invention can effectively reduce stray light, and causes point source transmittance PST value to be attenuated corresponding to several orders of magnitude, the manufacture is easy, and the cost is low, thus being suitable for any cold diaphragm structures.

Description

technical field [0001] The invention relates to the technical field of optical elements, in particular to a cold diaphragm with a light-blocking ring structure, which is used as a cold diaphragm inside a Dewar to effectively reduce stray light radiation energy reaching a detector. Background technique [0002] Space optical systems, especially space infrared optical systems and some large space telescopes, all work in "harsh" environments with strong radiation sources (such as the sun, moon, and earth) outside the field of view of the system; and in the infrared long-wave band, the system The stray radiation energy of the internal mechanical structure and other long-wave radiation reaching the surface detector is also a factor that cannot be ignored. At the same time, when the detection target signal is very weak, these strong stray radiations are often several orders of magnitude higher than the detected target radiation intensity, and through the diffraction of the apertur...

AI Technical Summary

Problems solved by technology

However, it is difficult to provide an effective cold diaphragm in practice because: (1) the black coating on the inner wall of the cold diaphragm cannot absorb stray light well (2) the size limitation of the Dewar makes the cold diaphragm unable to do enough Large and small cold apertures cannot effectively remove stray light radiation. If the size of the cold aperture is increased as much as possible, especially the opening size, it will increase the difficulty of cooling. (3) The inner wall of the cold aperture itself can transmit heat radiation to the detector. Especially the primary scattered light with high energy, so effective design is needed to improve the scattering situation

[0005] Most of the cold apertures reported in the literature are designed for cold apertures and still basically stay at the level of geometric dimension design. Generally, only optical aperture matching is required, the shape is a simple cylinder, and the materials are not carefully selected, so it is difficult to achieve the optimal design.

Images