A device for measuring the refractive index and temperature coefficient of refractive index of materials at low temperature

Abstract

The invention provides a device for measuring a material refractive index and a refractive index temperature coefficient under a low temperature, and the device comprises a collimation light source system, an optical spectroscope, an aiming system, a low-temperature vacuum cabin, a sample cabin, a double-sided rotary reflection mirror, an electric-control rotary platform and a collimator. When the temperature inside the sample cabin is reduced, the refractive index of a sample is reduced, a deviation angle delta also has slight variation delta, and the variation quantity of the deviation delta can be measured by the collimator, so that the refractive index of the material under the low temperature is changed. The device is based on the most conventional vertical incidence method, simple in principle and convenient to operate, a measured sample prism can be made of infrared materials and also can be made of the material in the visible light band, the application range is wide, the collimator is used for substituting a conventional coder for the measurement, the collimator is precise for measuring the slight variation of the angle, the collimator can be well applied to the slight variation of the deviation angle caused by the variation of the material refractive index under the low temperature, the cost of the device is reduced, and the measurement precision of the deviation angle is improved.

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 refractive index and temperature coefficient of refractive index of materials at low temperature. The device measures the refractive index of infrared or visible light materials and their temperature coefficient at low temperature at low temperature installation. Background technique [0002] The development of low-temperature optical technology provides an excellent observation method for infrared observation. In China, due to the lack of data on the refractive index value of infrared-transmitting materials at low temperatures and the rate of change of refractive index with temperature, currently only total reflection low-temperature optical systems can be developed. Therefore, one of the keys to successfully develop a catadioptric low-temperature optical system is to have the refractive index data of infrared material...

AI Technical Summary

Problems solved by technology

Refractive index measurement accuracy10 -5 , but 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 is 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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