Study On CW 670nm Red Laser

Diode pumped all-solid-state 670nm red laser sum up the advantages of DPL which are small volume, light weight compact structure,high reliability and high brightness of red laser,strong ability of tissue penetration eye-sensitive. So it is widely used in laser colour display and Laser Medical. At present,it is mainly used the method of LD end-pump working to investigate all-solid-state 670nm cw-red laser,which limited the output of the cw-red laser.LDA side-pumped Nd:YAP laser crystal and type-Ⅰcritical phase matching of LBO crystal were used in this paper.The theoretical simulation and experimental research were researched on the conversion efficiency of red laser.At last,high power of red laser was obtained.The main theoretical and experimental research contents were completed as follows:1.On the basis of phase-matching conditions of the frequency doubling crystal,phase matching angle, effective nonlinear coefficient and walk-off angle of the frequency doubling were calculated.The effect on the conversion efficiency of red laser of two crystals was compared,the type-Ⅰcritical phase matching of LBO crystal was used.2. On the basis of the small-signal solution of resonant three wave coupling equations of doubling frequency,the relationship of doubling efficiency and the spot radius of 1.34μm and the length of the LBO crystal were simulated, the qualitative curve was given.3.The thermal focal length of the Nd:YAP crystal was measured,according to the experimental data,the stability of the line cavity and V-cavity was analysed,and the parameters of the line cavity and V-cavity were designed.4.The effect on the conversion efficiency of red laser was researched in line cavity and V-cavity experiment; the qualitative curve that the relationship of the conversion efficiency of red laser and the spot radius of 1.34μm and the length of the LBO crystal was given.By using V-cavity, with incident pump power of 800W for the Nd:YAP crystal, the red laser output was 9.98W with the optical conversion efficiency up to 1.247%and the divergence of the laser beam was about 10mrad.