Investrigations On Diode-Side-Pumped High Repetition Freaquency Laser At 1.34μm

1.34μm high repetition rate generated by LD side-pumped laser has the advantages of compactness, high efficiency and long lifetime. Because 1.34μm is the safety wave range for human, it is widely used in the fields of Spectroscopy, fiber optics, laser medicine, optical communications and military applications. At the present,1.34μm laser is obtained by end-pumped. There is no report about LD side-pumped gain medium to get high repetition rate at 1.34μm laser. As the limitation of end pumped, that can not achieve high power output laser. As a matter of fact, this paper refers a new method to obtain 1.34μm, which is LD side-pumped Nd:YAP crystal by using V:YAG as passively Q-switched crystal. In the experiment, LD side-pumped Nd:YAP has been used to obtain high repetition rate 1.34μm laser. V:YAG was inserted in the resonant by property initial transmission. High repetition rate laser at 1.34μm was obtained. The main theoretical and experimental research contents are completed as follows:(1) This is the first time to realize diode-side-pumped passively Q-swiched Nd:YAP laser at 1.34μm with V3+:YAG saturable absorber.(2)It's the first time to calculate optimum curve of initial transmission of the passively Q-switched crystal V3+:YAG, mirror reflectivity efficiency and laser gain, which is helpful for choosing the passively Q-switched crystal. It makes us complete the experiment in timely.(3) According to properties of V3+:YAG on physical and chemical, the relationship of angle between polarization direction of V3+:YAG and the laser polarization direction, excited state absorption cross section and ground state absorption cross section is investigated. And we designed the Q-box, which can be rotated.(4) The cavity design is optimized by the ABCD transmission matrix of Gaussian beam. The influence between initial transmission of V3+:YAG to the passively Q-swiched laser at 1.34μm was investigated with experimental research. The relationship of pulse repetition frequency, pulse width,output power with pump power and initial transmission of V3+:YAG was obtained.(5) For the passive Q-switching operation, the maximum average output power of 3.95W was achieved under the pump power of 811W, corresponding to optical-to optical conversion of 0.49%. The highest peak power,the highest pulse repetition frequency and the shortest pulse width was achieved to be 1328W,14.3kHz,208ns respectively.