光回馈Nd:YAG激光器中的多模跳变现象  

Multi-mode hopping in Nd:YAG lasers with optical feedback

作　　者：谈宜东[1] 张书练[1] 

机构地区：[1]清华大学精密测试技术及仪器国家重点实验室,北京100084

出　　处：《物理学报》2007年第4期2124-2130,共7页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:60438010)资助的课题.~~

摘　　要：研究了Nd:YAG激光器中光回馈引起的多模跳变现象.光回馈调制了激光器不同纵模的阈值增益,阈值增益最低的纵模获得振荡.在外腔调谐过程中,当振荡模式的阈值增益高于相邻模式的阈值增益时产生模跳变,光强调制曲线出现相应的波动.各跳变纵模在增益曲线上的位置不同,导致模跳变点位置不同,相应的光强调制曲线也不同.越靠近中心频率的纵模,其光强信号峰值越大,该纵模持续振荡时间也就越长.当两跳变纵模关于中心频率对称时,其光强信号峰值相等,纵模持续振荡时间也相等.The multi-modes hopping in Nd： YAG lasers induced by optical feedback is presented. The threshold gains of different longitudinal modes are modulated by optical feedback. The mode which has the lowest threshold gain can oscillate. During the tuning of the external cavity length, when the threshold gain of the oscillating mode is higher than that of the adjacent mode, mode hopping occurs, and the intensity modulation curve fluctuates correspondingly. The different positions of hopping modes in the gain curve lead to different mode hopping points and intensity modulation curves. The closer to the center frequency, the larger intensity amplitude and the longer oscillating period the mode has. When the frequencies of two hopping modes are symmetric about the center frequency, the intensity amplitudes of them are equal, and their oscillating periods are equal too.

关 键 词：自混合干涉 模跳变 光回馈 阈值增益 

分 类 号：TN248[电子电信—物理电子学]