| The optical feedback effects in orthogonal polarized lasers contain plenty of knowledge of laser physics. Their applications in displacement measurement are the basic technology of metrology field and have the advantage of low cost and high accuracy. However, there is lack of systemic and effective theories to explain the physical principle behind the novel phenomena of optical feedback effects in orthogonal polarized lasers. The frequency stabilization of displacement measuring system is not considered to ensure the measurement accuracy. In this dissertation, the principle on optical feedback effects in orthogonal polarized lasers is systematically studied, the method of stabilized lasers'output frequency when optical feedback effect exists is proposed, and a set of displacement measuring system is developed.Main research contents and achievements include: (1) An orthogonal polarized laser feedback theory model based on cavity tuning is created. Lamb's semi-classical theory's vectorial and dual-frequency output extension are introduced to describe the orthogonal polarized characters of the laser. The feedback effects are coupled into the inner-cavity of the laser using F-P cavity theory. The multi-beam interference idea is used for different feedback level. This orthogonal polarized laser feedback theory model can explain phenomena, such as the intensity branches and obvious humpback on the opposite side of the two orthogonal polarized frequencies'curves appears, in frequency splitting laser with optical feedback effects. (2) Optical feedback's effect on lasers'net gain characters is studied theoretically and experimentally. It is discovered that the feedback beam's modulation on lasers'inner-cavity results in①Periodic waves superpose on Gauss-shape net gain curve of lasers without optical feedback, and the period of these waves are determinate by the proportion between the inner-cavity length and external cavity length.②The net gain curve is broadened which enlarges the bandwidth of lasers output light.③The values of lasers'net gain are increased and bring big modulated depth of lasers intensities. These are physical principles behind the novel phenomena of optical feedback effects in frequency splitting lasers. (3) The main factors that impact the form of feedback fringes are studied. The amplitude of feedback fringes increases as the reflectivity of feedback mirror increasing. For the same reflectivity, the longer the external cavity length is, the greater the amplitude will be. The phase delay between the two orthogonal polarized frequencies is determinate by the frequency difference and external cavity length. The experimental results are in good agreement with theoretical analysis. (4) Two proposals are brought up to stabilize the lasers'frequencies dynamically with feedback effects, peak value detection and mean value comparation. Combined with the static frequency stabilization technology, the final method of feedback displacement measuring system's frequency stabilization is presented. Then the system can work quickly and accurately in the large-scale and non-laboratory environment. These results have practical significance. (5) Frequency stabilized displacement measuring system with feedback effects is developed. Calibrated with the Aglient5529A interferometer, the specifications of the system are: range is 100mm, the measurement unit is 79.106291nm, measuring speed is 36μm/s～3cm/s , standard deviation of the whole range is < 0.4μm, linearity error is around 7×10-6 and dynamic frequency stability is better than 10?7 . This system has strong anti-disturbance ability and simple structure, be easy to use and non-contact measurement, which can bring a good application prospect.
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