Research On In-plane Displacement Measurement Based On Solid-state Microchip Laser Feedback Interferometer

The microchip laser feedback interferometer has the advantages of high sensitivity, easy alignment and simple structure, which can also work for the small, soft, crisp, non-cooperative targets. It has found wide applications in the field of aerospace, precision measurement and engineering technology. However, most of the interferometer can only measure the out plane displacement. The measurement of the in-plane displacement is also an important issue for the fabrication industries, such as the deformation of the material and the motion of MEMS. Aiming at this point, this paper designs and builds an in-plane displacement measurement system based on the microchip laser feedback interferometer, and the method for measuring in-plane displacement of a rough surface is studied.The main research work of this paper includes the following aspects:I The main in-plane displacement measurement methods and research status are introduced in detail in domestic and foreign. Then the characteristics of laser feedback technique are analyzed. On the basis of this, the principle of measuring the in-plane displacement is studied.II Putting forward and building the experimental system, which includes optical unit, signal processing unit and software system. Then the properties of the laser are studied and tested.III The performance text and the error analyze of the experimental system is studied. And basis on this, the measurement system is optimized.IV The beam collimation scheme for improving the system was applied to the microchip laser feedback interferometer to design a method which can measure the remote small vibration. Then, the remote voice vibration in distance of 71.7 meters is measured. Experimental results indicate the convenience of measuring.