连续钛宝石激光器光折变位相共轭外腔的实验研究

利用Ce：BaTiO3晶体构成的自抽运位相共轭(SPPC)外腔，改善了连续钛宝石激光器的工作特性，使得激光输出阈值由未加位相共轭腔时的4．7W下降到加位相共轭腔时的3．6W，斜率效率由26％上升为30％。利用外腔激光理论对该实验结果进行了合理的分析。此外，由于位相共轭自扫描效应，导致了输出光中心频率在反馈后3min时蓝移了142MHz，在6min时红移了243MHz。通过直接测量暗条件下自抽运位相共轭反射率的衰减，得到了自抽运位相共轭光栅的暗存储特性。在暗条件下，位相共轭反射率在开始的1．5h内由80．5％下降到75％，随后缓慢下降，到17h位相共轭反射率仍保持在74％。

Experimental Investigations of External Cavity Using Photorefractive Phase Conjugator for CW Ti:Sapphire Laser

With self-pumped phase conjugator (SPPC) of Ce∶BaTiO3, the performance of CW Ti∶sapphire laser has been improved. The output threshold decreases from 4.7 W (without phase conjugator cavity) to 3.6 W (with phase conjugator cavity) and the slope efficiency increases from 26% to 30%. Theoretic analyses with external-cavity laser theory are in accordance with the above experimental results. In addition, the frequency of the laser appears a blue shift of 142 MHz at 3rd minute after SPPC feedback and a red shift of 243 MHz at 6th minute after SPPC feedback, which are due to phase-conjugate self-scanning effect. Moreover, the dark storage characteristic of the SPPC grating is obtained by measuring the dark decay of SPPC reflectivities. In dark, the SPPC reflectivity declines from 80.5% to 75% in the initial 1.5 hours, subsequently decays slowly, and remains almost at the former value for about 15 hours.