中国激光, 2004, 31 (10): 1165, 网络出版: 2006-06-12
连续钛宝石激光器光折变位相共轭外腔的实验研究
Experimental Investigations of External Cavity Using Photorefractive Phase Conjugator for CW Ti∶Sapphire Laser
激光技术 钛宝石激光器 位相共轭外腔 Ce∶BaTiO3晶体 laser technique Ti∶sapphire laser phase-conjugate external cavity Ce∶BaTiO3 crystal
摘要
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4.7 W下降到加位相共轭腔时的3.6 W,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3 min时蓝移了142 MHz,在6 min时红移了243 MHz。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1.5 h内由80.5%下降到75%,随后缓慢下降,到17 h位相共轭反射率仍保持在74%。
Abstract
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.
张明, 洪治, 陈军. 连续钛宝石激光器光折变位相共轭外腔的实验研究[J]. 中国激光, 2004, 31(10): 1165. 张明, 洪治, 陈军. Experimental Investigations of External Cavity Using Photorefractive Phase Conjugator for CW Ti∶Sapphire Laser[J]. Chinese Journal of Lasers, 2004, 31(10): 1165.