Device for measuring material refractive index temperature coefficient under low temperature based on minimum deviation angle method

Abstract

The invention provides a device for a measuring material refractive index temperature coefficient under low temperature based on a minimum deviation angle method. The device comprises a collimation light source system, a spectroscope, a collimation system, a low-temperature vacuum bin, a low-temperature vacuum system, a sample bin, a rotary reflection mirror, an electrically-controlled rotary table and an encoder. The low-temperature vacuum system, the sample bin, the rotary reflection mirror, the electrically-controlled rotary table and the encoder are subsidiary to the low-temperature vacuum bin. The sample bin and the rotary reflection mirror are driven by a motor respectively and are disposed in the low-temperature vacuum bin. When the device is used for measuring, quasi-monchromatic parallel light beams are emitted from a collimation light source and are emitted into the low-temperature vacuum bin after refection by the spectroscope, placement angles of reflection mirrors on a triple prism and the encoder are rotated to be adjusted to figure out a position of a minimum deviation angle, the light beams are perpendicularly emitted into the rotary reflection mirror, finally return to the spectroscope and enter the collimation system after being reflected. The traditional minimum deviation angle method is modified, the auto-collimation principle and the minimum deviation angle method are combined, demands for high precision of a shaft encoder are lowered within equal measuring precision ranges, and accordingly systematic cost is reduced.

Description

Technical field [0001] The invention belongs to the technical field of optical precision measurement, and in particular relates to a device for measuring the temperature coefficient of the refractive index of materials at low temperatures based on the minimum deflection angle method. The device is a device for measuring the refractive index of infrared or visible light materials under low temperature conditions. Background technique [0002] The development of low-temperature optical technology provides an excellent way for infrared observation. In China, due to the lack of data on the refractive index value of infrared transmission materials at low temperature and the rate of change of refractive index with temperature, only a total reflection low-temperature optical system can be developed at present. Therefore, one of the keys to successfully developing a refractory low-temperature optical system is to have the refractive index data of infrared materials at low temperatures. I...

AI Technical Summary

Problems solved by technology

Refractive index measurement accuracy10 -5 , but it can only measure the low-temperature refractive index (0.4-1.7μm) from visible light to near-infrared, the temperature control range of the sample is 100~300K, and the system uses the vertical incidence method, which is sensitive to errors and only suitable for measuring refraction Samples with a lower refractive index are prone to total reflection when measuring samples with a higher refractive index, resulting in measurement failure

At present, there is no relevant report on the refractive index data of infrared materials at low temperature (below 120K) and the refractive index measurement equipment of infrared materials at low temperature in China. Therefore, the accurate measurement of the refractive index of infrared materials at low temperature is of great significance to the development of low temperature optics.

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