Self-mixing interference orthogonal detection vibration measuring device and method

Abstract

The invention discloses a self-mixing interference orthogonal detection vibration measuring device and method. A single-mode semiconductor laser diode adjustable in constant current source control outputs incidence laser, one part of the incidence laser is reflected to a second photoelectric diode, and optical signals are converted into current signals which are detected by a second photoelectricdetection module and fed back to a collecting module; the other part of the incidence laser is irradiated on the surface of a to-be-detected object and is reflected to a first photoelectric diode according to the original path, and the optical signals are converted into the current signals which are detected by a first photoelectric detection module and fed back to the collecting module. Comparedwith a traditional self-mixing measuring device, the self-mixing interference orthogonal detection vibration measuring device has the advantages that the orthogonal self-mixing signals can be acquired, inverse tangent demodulation of the vibration signals is completed, signal demodulation difficulty of the system is reduced, high displacement resolution is achieved, demodulation precision of the vibration signals of the system is improved, and real-time and online measuring can be realized.

Description

technical field [0001] The invention relates to the technical field of laser measurement, in particular to a self-mixing interference quadrature detection vibration measurement device and method. Background technique [0002] Laser self-mixing interference refers to the phenomenon that after the output light of the laser is reflected or scattered by external objects, part of the light is fed back into the laser resonator, and the output power of the laser is modulated, causing the output power of the laser to change, also known as the laser feedback phenomenon. By analyzing the change of laser output power, the information of external objects can be obtained. A laser is both a light source and a detector. Compared with the traditional two-beam interference system, the interference system based on the laser self-mixing phenomenon has only one optical channel, which has the advantages of simple structure, compactness, and easy alignment. It is currently widely used in paramet...

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Problems solved by technology

[0004] In order to overcome the defects in the prior art, the object of the present invention is to provide a self-mixing interference quadrature detection vibration measurement device and method, which solves the problem that the resolution of the existing self-mixing measurement device and method is not high, and the improvement of the resolution leads to system cost Technical issues such as greatly improved

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