摘要
提出并论证了一种新型双频激光器研究方案 ,即在激光二极管 (LD)抽运Nd∶YAG激光器的谐振腔内 ,插入一只集纵模选择与纵模分裂于一体的多功能元件———晶体石英F P标准具。因腔内存在双折射效应 ,每一激光纵模分裂为两个相互正交的线偏振模 ,即o模和e模 ;同样 ,Nd∶YAG激光增益带宽范围内标准具的唯一透射极大峰也一分为二 ,即分裂为o峰和e峰。使一个o模位于o峰的峰顶处 ,并使一个e模位于e峰的峰顶处 ,即可实现o模和e模的同时运转。将厚度为 0 6 45mm ,切割角 (晶体光轴与晶体表面法线间的夹角 )为 10°的晶体石英F P标准具 ,置于腔长为 40mm的Nd∶YAG激光谐振腔内 ,获得了双纵模同时振荡输出 ,其频差约为 2GHz。
A novel scheme of dual-frequency Nd∶YAG laser is proposed and demonstrated. The resonant cavity of the laser contains a piece of versatile element: crystal-quartz-made birefringent Fabry-Perot etalon, serving as both a selector and a splitter of laser axial-modes. Because of the intra-cavity birefringence, each longitudinal mode is split into two linearly and orthogonally polarized components, that is, ordinary mode (o-mode) and extra-ordinary mode (e-mode). Meanwhile due to the same reason, the unique transmission maximum of the etalon within the overall lasing bandwidth of the Nd∶YAG laser is also split into two transmission maxima, namely, ordinary light transmission maximum (o-peak) and extra-ordinary light transmission maximum (e-peak). Simultaneous operation of the two axial modes can be obtained, by making an o-mode coincide with the central position of the o-peak, and an e-mode with that of the e-peak. A piece of birefringent Fabry-Perot etalon, with a geometrical thickness of 645 micrometers and a cut-angle of ten degrees between the quartz crystalline axis and the normal of its surfaces, has been designed and fabricated. A frequency-difference of approximately two gigahertz has been obtained experimentally, when the above birefringent etalon being placed in a 40-millimeter-long cavity of the LD pumped Nd∶YAG laser.
出处
《中国激光》
EI
CAS
CSCD
北大核心
2001年第2期100-102,共3页
Chinese Journal of Lasers
关键词
大频差
双频激光器
双折射效应
二极管抽运
ND:YAG激光器
large frequency-difference, dual-frequency laser, Nd∶YAG, effect of birefringence, Fabry-Perot etalon
