Side Pumped Solid State Master Oscillator Power Amplifier With High Output Power And Excellent Beam Quality

This paper is composed of two parts:A novel theory of spherical aberration self compensation is proposed to be utilized in beam quality enhancement in solid state Master Oscillator Power Amplifier, and an experimental setup of side pumped Master Oscillator Power Amplifier with high power and excellent beam quality.Thermal effect has always played an important role in the design of solid state lasers, especially in high power configuration. In Chapter2, an clear analysis of the thermal effect in side pumped rod-type Nd:YAG crystal is provided. Great attention is paid to thermal induced spherical aberration effect and its influencing factor, its influence to lasers and laser amplifiers.In order to compensate for the positive spherical aberration in Nd:YAG crystal, aspherical lens or phase conjugate mirrors was used to induce a negative spherical aberration. However, these components are complicate in design as well as highly-cost in manufacture. In chapter3, a novel theory of spherical aberration self compensation is proposed in theory, predicting an inversion from positive spherical aberration to negative spherical aberration. Moreover, the theory can be utilized in achieving high power and excellent beam quality output in solid state Master Oscillator Power Amplifier.Based on the theory of spherical aberration self compensation, an experiment of beam quality enhancement has been carried out to testify its accuracy. A three-stage side pumped Master Oscillator Power Amplifier with high power and excellent beam quality has also been developed, achieving an output of130W and beam quality of M2x=1.46, M2y=1.35in continuous wave configuration. In Q-switched configuration, an output of125W is obtained with repetition rate of10kHz and pulse width of75ns.