拉曼泵浦光源退偏技术研究

文中利用琼斯(Jones)矩阵和斯托克斯参量分别对几种拉曼泵浦光源退偏方式进行了理论分析,并对实际的激光器光谱进行了偏振度的数值计算.在采用基于偏振合光(PBC)的方法进行退偏时,只有当两激光器的光功率相同时才可以得到最小的偏振度;在采用偏振合光加双折射晶体退偏(PBCD)时,计算表明,随着晶体长度的变化,偏振合波后的偏振度总小于单只激光器通过晶体后的偏振度,因此晶体长度的设计应为使单只激光器退偏所要求的晶体长度,这样可保证不同泵浦情况下的偏振度.文中的设计方法和结论对拉曼放大器的泵浦光源退偏设计具有一定参考作用.

Study of depolarization of Raman pump source

Theoretical analysis has been made of several kinds of Raman pump laser depolarization based on Jones matrix and Stock parameters and the numerical computation of the depolarization degrees of the actual laser spectrums performed.When the Polarization Beam Combined(PBC) method is adopted,the minimum Degree Of Polarization(DOP) can be obtained only when the optical powers of the two lasers are identical.However,when PBC plus the birefringent crystal depolarization are adopted,the DOP after PBC is always smaller with the variations of the crystal length than that when a single laser runs through the crystal.Therefore,the crystal length should be so designed as required by single laser depolarization to maintain the DOP with different pump sources.The design method and conclusion presented in this paper may contribute to the depolarization design for the pump laser of Raman amplifiers.