LD End-Pumped Innoslab Laser

Partially end-pumped hybrid slab laser has advantages such as compact structures,good mode overlap between pump volume and laser mode,good beam quality,high efficiency,simple power scaling and so on.It is especially suitable for high power and good beam quality laser operating.Based on the hybrid amplifier cavity,in the horizontal direction,the increase in beam cross section by the beam expansion balances the power increase at amplification and keeps the intensity roughly constant;in the vertical direction,the laser mode is reproduced by the thermal lens,which is advantage for seeder amplifier.Based on the Innoslab structure laser and amplifier,we did the studies listed below in this thesis.1.The upper level direct pump could improve the stokes efficiency and reduce the thermal load,thus obtained higher output power and beam quality.808nm LD end-pumped Nd:YVO₄ slab laser using positive branch confocal hybrid resonator,the output power was160W with the optical to optical efficiency and slope efficiency were 41.4%and 49.6%.When the output power was 145W,the beam quality were 1.37 and 2.21 in the orthogonal directions.When the wavelength of the LD was 880nm,the output power was 170W with the optical to optical efficiency and slope efficiency were 47.7%and 56.7%,and the beam quality were 1.3 and 1.9 in the orthogonal directions.The dual-end-pumped could make the gain medium thermal distribution more uniform,so as to keep the beam quality,the more power could be injected to gain medium and obtain higher output power.880nm LD dual-end-pumped Nd:YVO₄ slab laser using positive branch confocal fold hybrid resonator,the output power was 330W with the optical to optical efficiency and slope efficiency were48%and 58.9%.When the output power was 300W,the beam quality were 1.7 and 2.1 in the orthogonal directions.When using negative branch confocal fold hybrid resonator,the output power was 416W with the optical to optical efficiency and slope efficiency were54.3%and 61.6%.When the output power was 370W,the beam quality were 3.9 and 4.7 in the orthogonal directions.The upper level direct pump and dual-end-pump could reduce the thermal load and thermal effect,thus,more pump power could be injected into the gain medium and obtain more output power.2.940nm LD end-pumped Yb:YAG slab laser,and the coupling system was consisted of only two cylindrical lenses,with the plane-concave cavity,the maximum output power was 280W,the optical efficiency and slope efficiency were 41.2%and 48.3%,respectively.When the positive branch confocal hybrid resonator was used,the input spherical mirror with the radius of 220mm and the output cylindrical mirror with radius of-150mm,the output power was 156W with the optical efficiency and slope efficiency were 22.9%and37.1%,respectively.The beam quality were 1.04 in the horizontal direction and 1.01 in the vertical direction.When the positive branch confocal hybrid resonator was used,the input spherical mirror with the radius of 180mm and the output cylindrical mirror with radius of-150mm,the output power was 205W with the optical efficiency and slope efficiency were30.2%and 41.8%,respectively.The beam quality were 1.05 in the horizontal direction and1.89 in the vertical direction.3.For the seeder of 30KHz,6W,5ns,and the gain medium was 18mm×10mm×1mm Nd:YVO₄,using the traditional amplifier cavity with the spherical input mirror R=500mm and the cylindrical output mirror R=-350mm,the maximum output power was 77W with the optical efficiency was 27.9%,and the beam quality were 1.52 and 1.36 in the orthogonal directions.For the seeder of 10KHz,0.4mJ,3.4ns,and the gain medium was14mm×10mm×1mm Nd:YVO₄,using the plane amplifier cavity,the maximum output energy was 8.4mJ,3.6ns with the optical efficiency was 29.8%,and the beam quality were1.48 and 1.39 in the orthogonal directions.For the seeder of 5KHz,0.3mJ,3ns,and the gain medium was Nd:YAG,using the amplifier cavity with the spherical input mirror R=500mm and a serial of cylindrical output mirror R=-350mm,after 12 passes,the maximum output power was 25mJ,3ns with the optical efficiency was 14.3%,and the beam quality were 1.7 and 1.5 in the orthogonal directions.