【摘要】 由入射强激光束的强度或相位调制引起的小尺度纹波在经过非线性介质后 ,将产生强烈的自聚焦效应。在非线性相位延迟 ( B积分 )超过一定值后 ,将严重影响光束的近场强度分布 ,甚至造成丝状破坏。数值模拟和实验研究了在一定强度调制下的光束经过钕玻璃介质发生自聚焦成丝效应的阈值条件 ,以及非线性传输的一般规律。可以通过模拟计算 ,给出高功率激光系统设计中的 ΔB判据。更多还原

【Abstract】 Small-scale ripples in intense l aser beams caused by intensity or phase modulations will grow fast due to self- focusing effect after passing through the nonlinear media. This lead to the chan ge of the intensity distribution in the beam and can cause media damage by filam entations when the nonlinear phase retardation(B integral) reach to the rest riction value which partly depends on the primary ripple level. The certain ΔB restriction of laser system was obtained by numerical simulations which we re coincidence with experiments on beam propagation in a rod Nd- 3+:glass.更多还原