METHOD OF MEASURING REFRACTIVE INDICES OF OPTICAL MATERIALS IN SOLID STATE OR IN FORM OF MELT Russian patent published in 2020 - IPC G01N21/41 

FIELD: measurement.

SUBSTANCE: invention relates to a method of measuring refractive indices of optical materials in a solid state or in form of a melt. Method is characterized by that a sample of the analysed material is heated to a temperature which enables to detect its heat radiation; determining angular diagrams of intensity of thermal radiation emanating from the surface element of the sample of the analysed material for two mutually perpendicular polarisations; determining the maximum value of the difference in thermal radiation intensity diagrams, depending on the refractive index of the sample of the analysed material, which is achieved in the range from the Brewster angle to the angle of total internal reflection; based on the value of the maximum difference in the heat radiation intensity diagrams, the refractive index of the sample of the analysed material is calculated; wherein the probing radiation used is the intrinsic thermal radiation of the sample of the analysed material.

EFFECT: technical result is wider range of methods of measuring optical properties of refractive index of optical material in the form of a melt at high temperatures, determining the refraction index of the analysed material in a wide spectral range without using external sources of probing radiation, simplifying the measurement circuit.

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