Optical System Design For LD Pumped Green Laser

Because of outstanding characteristics of the beam and increasingly mature technology of commercial productions, LD pumped green laser is widely used in many fields. It is focused by more researchers and it has become one of the most hot research issues of LD pumped solid-state laser. This dissertation is studied the optical system of LD pumped green laser. The purpose that achieves is to complete the optical system design of LD pumped green laser, including the design of resonator and collimation system. The main contents and the innovations of the study can be summarized as follows:Firstly, the equivalent method of optical effect is proposed and applied to the calculation process which deduces the expression of laser beam parameters. The laser beam is located in the optical resonant cavity of LD pumped green laser. The calculation process is based on the optical matrix, and the thermal lens focal length is introduced into the optical transform matrix, then the optical component group between input mirror and output mirror is regard as an optical component which optical effect is the same as the optical component group. The calculation process including the straight cavity and the three-mirror folded cavity as well as the four-mirror folded cavity is simplified by introducing the equivalent method.Secondly, the ray-tracing method is proposed for analyzing optical collimation system. This method establishes Cartesian coordinate system firstly, and then the specific ray is traced. Compared with Gaussian lens transformation formula, the ray-tracing method, in which the aberration of optical system is hidden in the beam transformation process, is well. The ray-tracing method fetches up the disfigurement that Gaussian lens transformation formula overlooks. The result which calculates by the two methods respectively is compared. And the compared result can be as a basis for determining the optical collimation system that designed is good or bad.Thirdly, the optical system which satisfies the request of given LD pumped green laser is designed. The experimental program is determined by comparing, and then optical resonant is analyzed according as the theory and the parameters of the laser beam collimation system are gained though calculation. It is used the ray-tracing method to analyze the aberration of optical collimation system that designed. And the estimation, of which the optical collimation system is good or bad, is confirmed according to the result that above. At last, the parameters are altered or not according to the experiment. The optical system design of given LD pumped green laser is well accomplished, of which the divergence angle of the laser beam is less than 2mrad and the quality of the beam is good and the output power is steady.