Measuring device and measuring method of refractive index of transparent material

Abstract

The invention discloses an apparatus and a method for measuring the refractive index of a transparent material. The apparatus includes a super-continuum laser device, a grating monochromator, a chopper, a sample to be measured, a high-speed photoelectric detector, a driver, a lock-in amplifier and a computer. The super-continuum lasers and the grating monochromator are used for generating a monochromatic laser beam needed by the measurement, the chopper is used for modulating the continuous laser beam into a square wave signal, the high-speed photoelectric detector is used for receiving the modulated square wave laser intensity signal traversing through the sample to be measured, the lock-in amplifier is used for measuring a phase difference between a voltage signal output by the high-speed photoelectric detector and a reference signal output by the driver, and the lock-in amplifier is used to measure a phase difference between a signal of a test laser path with the sample and a signal of the test laser path without the sample in order to calculate the refractive index of the sample to be measured. The apparatus and the method have the advantages of easiness in preparation, fast measuring speed, high measuring precision, and realization of the rapid measurement of the refractive index in a certain wavelength range.

Description

technical field [0001] The patent of the present invention relates to the field of measurement of the refractive index of materials, especially a device and method for accurately and rapidly measuring the refractive index of transparent materials. Background technique [0002] Refractive index is a basic physical quantity that characterizes the optical properties of materials, and its accurate measurement is of great significance. At present, there are many methods for measuring the refractive index, and the commonly used ones are: (1) using the minimum deflection angle method of the spectrometer. Although this method has high measurement accuracy, it has high requirements for the sample to be tested. In addition to processing the sample into a prism In addition, there are high precision requirements for the vertex angle of the processed prism and the flatness of the two planes, which increases the measurement cost. In addition, the adjustment of the spectrometer is more com...

AI Technical Summary

Problems solved by technology

At present, there are many methods for measuring the refractive index, and the commonly used ones are: (1) using the minimum deflection angle method of the spectrometer. Although this method has high measurement accuracy, it has high requirements for the sample to be tested. In addition to processing the sample into a prism In addition, there are high precision requirements for the vertex angle of the processed prism and the flatness of the two planes, which increases the measurement cost. In addition, the adjustment of the spectrometer is more complicated, and there are many steps to measure the minimum deflection angle. The measurement work It is quite heavy and the measurement efficiency is low; (2) Abbe refractometer critical angle method, this method can generally measure 4 significant figures, but the calculation formula is relatively complicated, there are many factors that cause errors, and the refractive index of the sample must not be It is greater than 1.7, which limits the scope of application of this method; (3) interferometry, which is to calculate the refractive index of the sample to be measured by measuring the phase difference. The main problems are that the phase extraction steps are numerous and the operation is troublesome.

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