Research On Dual-channel Self-mixing Velocity Measurement Based On The Fiber Ring Laser

Since self-mixing interfere sensing technology has been widely employed in industrial application, biomedical detection, military technology areas and so on, it has attracted many researchers attentions. To begin with we provided a brief background on the velocity measurement. We have discussed different velocity measurement technology and described self-mixing velocity measurement in details. The research contents of this paper were mainly focused on dual-channel self-mixing velocity measurement based on Er-doped fiber ring laser. We have deduced the fiber ring laser self-mixing interfere model and studied the dual-channel self-mixing velocity measurement theory. In practice, emphasis is placed on the constructions of the dual-channel self-mixing velocity measurement system based on fiber ring laser which we used to do many experiments and discussions. The experimental results revealed that our dual-channel system is more accuracy than the traditional one which is suited for different measurement environment. The research work we have devoted to in this paper mainly include:1. Based on laser steady state equation and fiber ring laser transmission equation, we have built up fiber ring laser self-mixing interfere model. Combined with our self-mixing velocimeter with orthogonal-beam incident system (OSMV) velocity measurement model, we have deduced the principle theory of the dual-channel system and made analog simulation.2. The laser Doppler velocity measurement theory has been studied deeply. Based on the previous word, we successfully establish symmetry dual-beam incident system which employing fiber ring laser as laser source. The symmetry dual-beam incident system improves the intensity of the signal and eliminates influence of the longitudinal parasitic velocity making velocity measurement more accuracy. And the error of the velocity measurement with the system is able to be controlled lower than2.033617%3. Based on the velocity measurement model of our (OSMV), we have build up the novel self-mixing velocimeter with orthogonal-beam incident system which enables the velocity measurement without knowing the incident angle information. The system effectively reduces the influence caused by the incident angle variation. The result indicates a much better linearity of our novel velocimeter than the traditional one in the turntable experiment. The relative error rates of our novel velocimeter system are up to1.258%with velocity range of26.670mm/s to426.727mm/s.The innovation of this paper mainly contains:1. We have build up fiber ring laser system and deduced the fiber ring laser self-mixing interfere model. Furthermore, we simulated the purely physical process of dual-channel velocity measurement, which constitute the theoretical basis for the later experiment and application. Narrow line width and stabilized laser below kHz was obtained, which a high-performance source for high precision and high sensitivity remote self-mixing interference system.2. We successfully establish symmetry dual-beam incident system which employing fiber ring laser as laser source. The symmetry dual-beam incident system improves the intensity of the signal and eliminates influence of the longitudinal parasitic velocity making velocity measurement more accuracy.3. We present a method of velocity measurement using of a novel self-mixing velocimeter with orthogonal-beam incident system (OSMV) which enables the velocity measurement without knowing the incident angle information. The system make velocity measurement more accuracy and convenient.