The Research Of LD End-pumped Nd:YVO₄/Nd:YVO₄Slab Laser

LD end-pumped slab laser with hybrid resonator (Innoslab laser) is well suited forgenerating laser with high power and high beam quality. Its geometry of partially endpumping could provide good overlap between pump and laser mode. The thermaleffect would be effectively reduced for the large cooling faces of slab and the outputbeam has high beam quality in both directions as a result of hybrid resonator.In this thesis, some works on the laser properties of Nd:YVO4and Nd:GdVO4havebeen done based on Innoslab laser. The main contents can be outlined as follows:1. A brief introduction to DPSSL has been made. The characteristics of Nd3+lasercrystals and the technique of Partially-end-pump were described in details.According to the classical four-level rate equation, laser output power and slopeefficiency were deduced. Comparison of thermal length and temperaturedistribution was made when the pumping sources were with differentwavelengths and the laser crystal were in different sizes.2.880nm LD stacks pumped Nd:GdVO4slab laser, with a negative confocalunstable-stable hybrid resonator, was constructed to generate1063nm output.149W laser output was realized when the pump power was390W. Theoptical-optical conversion efficiency was38.2%and the M2factors were2.3inboth directions. Starting from the ABCD matrix method, the fundamental modesize of resonator was calculated with consideration of thermal lens effect. Therelation between mode overlap and beam quality was discussed by comparing ourexperimental result with previous one. When fundamental mode size was muchsmaller than the pump size, the oscillation of low order mode would deterioratethe beam quality.3. A compact Nd:YVO4Innoslab laser end-pumped by880nm laser-diode stackswas presented. A maximum output power of328W was obtained at the absorbedpower of712W, corresponding to an optical conversion efficiency of46%and aslope efficiency of57%. At the output power of303W, the M2factors in theunstable direction and in the stable direction were1.7and2.1, respectively.