利用激光二极管(LD)端面抽运YVO4-Nd:YVO4复合晶体,采用四镜环形谐振腔及Ⅰ类临界相位匹配(CPM)LBO晶体进行腔内倍频,在腔中插入TGG晶体和λ/2波片组成的光学单向器,设计了满足热不灵敏条件和最佳倍频条件的谐振腔型,实现了全固态连续稳频倍频红光激光器。在19 W抽运功率下,同时获得了610 mW的671 nm单频红光输出和400 mW的单频1342 nm红外光输出。红光30 min内输出功率波动小于±0.6%。自由运转时,基频光(1342 nm)1 min频率漂移为±5 MHz,锁定后基频光1 min频率稳定性优于±1 MHz。

A continuous wave (CW) frequency-doubled and frequency-stabilized laser with red light output was designed and built. The laser resonator is in a ring configuration consisting of four mirrors, and a YVO4-Nd:YVO4 composite crystal end-pumped by a laser-diode serves as the laser material. A type-I critical phase-matched (CPM) LBO crystal and an optical diode constituted by a TGG and a λ/2 waveplate are placed inside the resonator to be used for the intracavity frequency-doubler and for forcing the laser to operate unidirectionally, respectively. The optical resonator is designed to satisfy the conditions of the thermal insensitivity and the optimum frequency-doubling. Under the pumped power of 19 W, the single-frequency second-harmonic-wave output of 610 mW at 671 nm wavelength and the fundamental laser output of 400 mW at 1342 nm are obtained, simultaneously. The intensity fluctuation of the output red laser is less than ±0.6% in 30 minutes. With and without the frequency-stabilizing servo system on, the laser frequency shifts at 1342 nm wavelength are better than ±1 MHz and ±5 MHz within 1 minute, respectively.