Feasibility Study Of Automatic Optical Resonator Stability Conditioning Systems

Since the invention of laser, adjustment system for the stability of the resonator has been taken into consideration in research of laser. Some internal and external factors may disalign the mirror and lead to the deviation of output beam from ideal status. So the research on the stability of the resonator is of special importance. In this thesis, we discussed an automatic resonator adjustment system. The research includes several technical fields such as optics, mechanics, automatic control and computer science. We deduced the relation function between the incline angle of the resonator mirrors and the deviation of output pattern position using optics law. According to the relation ,we can obtain the incline angle. In order to validate the theory, we design stable equipment of resonator. The mirror with an elliptic inner hole deflects the output beam of laser to a CCD sensor. The data of the image received by CCD is transformed into a micro-computer and the image is processed and analyzed. Finally we detect the inner and outer edge of the cirque, get the centeral position of the ring by fitting the curve and obtain the deviation of optics maladjustment. We can obtain incline angle according to the deviation of optics maladjustment and transfer the angle into control system. In control system ,four micro-motors control four angles of the two mirrors. Using advanced control technique, motor controller operate speed and displacement of each motor and compensate the maladjustment of resonator. Experiment result has proved that this stable adjustment method is reasonable and can improve stability of resonator.