Research On High-power Slab Laser Oscillators And Amplifiers

LD partially-end-pumped slab laser is one of the most efficient ways to generate powerful laser output with excellent beam quality. Therefore, more and more research groups utilized this kind of structure to fulfill the output of laser with high power and good beam quality. For this kind of laser, there are five characteristics:LD stack as a pumping source, the pumping efficiency has been improved greatly; the heat inside the crystal is mainly transferred by thermal conduction through two large faces of slab, causing the lower thermal effect; the coupling system makes the light intensity homogeneous in the horizontal direction, eliminating the temperature gradient; the partially-end-pumped style causes the mode matching, improving the conversion efficiency; and the last one, the output beam has a near-diffraction-limited beam quality in both directions as a result of hybrid resonator. In the thesis, the output characteristics of the laser applying this structure is researched, and the amplification results are discussed. The main contents are as following:1. The development of slab laser and the characteristics of this new kind of structure slab laser are introduced and the researching significance of slab amplifier lasers is involved.2. Based on the equation of thermal conducting, the temperature distribution inside the slab crystal in the form of sing-end-pumping and double-end-pumping was calculated, and the detailed simulated pictures are presented. The results showed that double-end-pumped slab crystal could lower the thermal gradient.3. Adopting the resonator of positive-branch and negative-branch, the characteristics of output laser and the comparison between their differences are analyzed.4. The development of slab amplifier laser is introduced and the possibility of making up an amplifier laser using paralleled-plane cavity is analyzed theoretically. Some experiments concerning the amplifying results are demonstrated.