Behavioral Model Of Optical Feedback Self-mixing Interference Effect And Displacement Measurement Systems

The optical feedback self-mixing interference technology is an emerging technique and it is especially suitable for measurement of displacement, distance, velocity and other physical measurements as well as the parameters of the laser itself.In the optical feedback self-mixing measurement systems, the model of the self-mixing interference is modified by the strength of the back-scattering and by nonlinear phenomena governing the global behavior of the laser diode. Affect the self-mixing signal shape at last. This makes signal processing rather challenging. That is an important factor which affects the practical use of the optical feedback self-mixing measurement technology. In order to simplify date processing, in this paper, a simulation behavioral model of the optical feedback self-mixing interference effect based on orcad10.5 of cadence is proposed, and on this basis a behavior model of displacement measurement systems of the optical feedback self-mixing interference is established. It is an simulate electronic circuits composed of a set of basic components such as resistance, capacitance, amplifier and triggers. So this model is visualization and has definite physical meaning. Moreover this method simplified the nonlinear equation in self-mixing phenomenon.The displacement measurement system was established in this paper is a high accuracy and real time displacement measurement system, and the simulation results close to the actual conditions. It is a valuable reference for hardware design which based on the optical feedback self-mixing measurement systems.At first, analyzed theoretical model of the optical feedback self-mixing interference effect; On the basis of the mathematics model of three-mirror cavity, established a simulation behavioral model of the optical feedback self-mixing interference effect in this paper, and made the simulation results compare with the theoretical and experimental.Secondly, on the basis of the simulation behavioral model of the optical feedback self-mixing interference effect, a behavior model of the displacement measurement systems of the optical feedback self-mixing interference was established. Analysis the simulation results found that the measurement systems suitable for any optical feedback condition, under the moderate optical feedback, the measurement error within±7nm.Afterwards, reconstruct the displacement of experimental data and found that the experimental absolute error within±80nm. The accuracy of the model is further proved.Finally, conclusions are drawn from the whole paper and the further research issues are pointed out.