Research of amplified spontaneous emission in high power slab laser amplifier

The amplified spontaneous emission(ASE) effects in high power laser slab amplifier are investigated by theoretic simulations. A time-related 3D ASE model is developed with which the ASE effect in large aperture Nd:glass amplifier is investigated in detail. The effects of ASE to the stored energy efficiency and to small signal gain coefficient are got under different pump voltage, pump time, stored energy distribution and different gain-length product. The simulation results in the 4×2×3 amplifier indicate that the effect of ASE is stronger with the improved charge voltage, the loss of average stored energy is 21.0% by ASE, the loss of small signal gain coefficient is 16.62%，the uniformity of small signal gain coefficient is 7.44% over the aperture while pumping voltage is 23kV. The gain