论文部分内容阅读
提出利用Ⅱ类相位匹配方法实现稳定倍频输出,并对该方法进行了理论分析和数值模拟。数值模拟是对KTP晶体xy平面内的Ⅱ类相位匹配倍频过程进行的。数值计算结果表明,Ⅱ类相位匹配倍频过程中,当基频光以除最佳入射偏振角之外的偏振方向入射时,倍频强度曲线随倍频晶体长度增加而呈周期性变化;由于这种周期性变化的存在,当基频光起伏变化时,倍频强度曲线会交叉汇聚,出现倍频稳定区;当偏离角(入射偏振角与最佳入射偏振角差值)一定时,随着基频光入射强度的增大,实现稳定倍频输出所需的倍频晶体长度减小,稳定输出时倍频效率不变;当基频光强度一定时,随着偏离角的增大,倍频输出稳定性提高,倍频效率稍有下降。
Proposed to use phase Ⅱ phase matching method to achieve a stable frequency output, and the method of theoretical analysis and numerical simulation. Numerical simulation is carried out on Phase II phase-matching frequency doubling in the xy plane of KTP crystal. The numerical results show that the frequency doubling intensity curve changes periodically with the doubled crystal length when the fundamental frequency light is incident on the polarization direction except for the best incident polarization angle in Phase Ⅱ frequency-doubling process. Since The existence of this periodic change, when the fundamental frequency fluctuations, the frequency-doubling intensity curve will cross convergence, frequency stability zone appears; when the deviation angle (incident polarization angle and the best angle of incidence polarization) is constant, with With the increase of the incident light intensity of the fundamental frequency, the frequency doubling crystal length required to achieve a stable frequency-doubling output is reduced, and the frequency-doubling efficiency is unchanged when the output power is stable. When the light intensity of the fundamental frequency is constant, with the increase of the deviation angle, Multiplier output stability increased, frequency multiplication efficiency decreased slightly.