Liquid film thickness measuring system based on optical microwave interference

Abstract

The invention provides a liquid film thickness measuring system based on optical microwave interference. The system is characterized by comprising a broadband carrier light source (1), a frequency tunable microwave source (2), an electro-optical modulator (3), an optical amplifier (4), a first 1*2 multimode optical fiber coupler (5), a self-focusing lens (6), a convex lens (7), an optical coupling lens (8), a multimode transmission optical fiber (9), a second 1*2 multimode optical fiber coupler (10), a high-speed photoelectric detector (11), a lock-in amplifier (12), a vector microwave detector (13) and a computer (14). According to the invention, high-precision measurement of the liquid film thickness can be realized.

Description

technical field [0001] The invention belongs to the field of multiphase flow detection, in particular to a liquid film thickness measurement system based on light-borne microwave interference. Background technique [0002] Multiphase flow, as a multiphase fluid with two or more different phase states and a clear interface, widely exists in industrial production and life, such as petrochemical, energy and power industrial processes, natural gas, petroleum, low boiling point liquids, etc. The transmission process of heat and mass transfer equipment, the separation and reaction process of heat and mass transfer equipment, blood circulation and metabolic processes in biological systems, as well as satellites, space stations and transport spacecraft in the aerospace field, in which liquid film is an important part of its common flow form Therefore, the realization of accurate measurement of liquid film thickness is of great significance to the study of multiphase flow flow struct...

AI Technical Summary

Problems solved by technology

However, there are also some problems in the traditional optical fiber all-optical interferometer. For example, in order to obtain high-quality interference signals, only single-mode fiber can be used. Because of the large mode dispersion of multi-mode fiber, the noise caused by multi-mode interference will lead to lower fringes. Visibility

Moreover, when the traditional optical fiber all-optical interferometer performs measurements in the optical domain, it is necessary to strictly control the polarization state of the interfering beam to avoid the problem of polarization fading. Therefore, it is usually necessary to use a polarization-maintaining fiber that is expensive and complicated

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