| The Cr4+:YAG laser is pumped by Laser-Diode which wavelength ranges from 1.3 to 1.6μm.This unique wave band is in the eye-safe region and also have low-loss and low dispersion for optical fiber. So such laser can be wildly used in the fields of optical communication, laser radar ,medical treatment and scientific research et al.Hence there is great scientific signification and application value in the research of tunable Cr4+:YAG laser .The main contents as followings:The research of Cr4+:YAG laser in this report is pumped by 980nm diode laser instead of Nd3+ 1064nm laser .The laser have many virtues .It has small volume and high efficiency .It can be tuned easily and also has a stable output . As the gain-medium , the development and significance of the research about LD pumped Cr4+:YAG laser in home and abroad and Cr4+:YAG crystal's mail application are discussed.Based on the rate equation theory, the output properties of LD end-pumped solid-state lasers are analyzied. The mode-overlap between pumping mode and oscillating mode is studied and analyzed on the position of focusing spot, the angle of pumping laser divergence and the transmission rate of output mirror. These provide theoretical basis of our experiment.The temperature distributing in the crystal is analyzed. Several methods to measure the thermal-focus and compensate the thermal effect are also summarized.A Birefringence-Filter is designed inovativly.It can be used as a tunable element in the laser ,and also can be used as a astigmatism compensation element . The influences of the system parameters (incident angle, azimuth of optical axis and thickness of filter) on the filtering properties are discussed.Based on the cavity propagation matrix theory , we designed two cavities of end-pumped laser in view of the astigmatism and thermal lens effect etc .That is three lens and four lens thermally stabilized cavities of laser which can compensate astigmatism.We also calculate the cavity parameter based on stability-area and... |
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