A device for measuring refractive index by optical fiber interferometry

Abstract

The invention discloses a device for measuring a refractive index through an optical fiber interferometry. The device comprises a laser light source, a circulator, a sample reservoir, a photoelectric detector, a demodulation module and a collimator, wherein the collimator is arranged at one end of the sample reservoir; a 10%-reflecting 90%-transmission type lens is arranged in the collimator; a Faraday rotating mirror is arranged at the rear end of the sample reservoir; the light emitted from a laser passes through the collimator, and then becomes parallel light, emits into the sample reservoir and is reflected by the Faraday rotating mirror at the rear end; the Faraday rotating mirror can avoid the interference between the incident light and the reflected light in the sample reservoir; the two paths of light, namely, the reflecting light of the collimator and the reflecting light of the Faraday rotating mirror, have interference phenomenon. The device provided by the invention is high in measuring precision, is simple in structure, is easy to realize miniaturization, can be used for measuring various samples of gas and liquid, is wide in measuring scope of refractive index and can realize the digital automatic measurement.

Description

technical field [0001] The invention relates to a device for measuring refractive index by optical fiber interferometry, which performs high-precision digital measurement of the refractive index of gas and liquid through the principle of optical fiber interferometry. Background technique [0002] At present, the traditional method of measuring the refractive index is mainly through the Abbe refractometer. The position of the corner is the area where the axis forms a light-dark boundary, and the measurement of the refractive index of the sample is realized by detecting the position of the light-dark boundary. Due to the principle of total reflection, the range of measuring the refractive index is limited to a certain extent, and it cannot be measured for samples with high or low refractive index. The Abbe refractometer is built with purely physical optical devices, it is difficult to build and adjust the optical path, the overall operation of the instrument is complicated, a...

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Problems solved by technology

[0004] In order to overcome the difficulties in the construction of the optical path of the traditional refractive index measuring instrument, the complicated operation, the inability to realize digital automatic measurement, and the small range of the measured refractive index, the present invention provides an instrument for measuring the refractive index by optical fiber interferometry. The refractive index of the sample is measured with high precision, strong anti-interference ability, wide range of refractive index measurement, various types of detection samples, and the instrument can realize digital real-time measurement function

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