利用半导体激光器端面抽运Nd3+:YAlO3(Nd:YAP)晶体,采用五镜环形谐振腔及KTiOPO4(KTP)晶体进行内腔倍频,同时获得了0.54 μm和1.08 μm双波长连续激光输出。计算并比较了谐振腔的两个凹面镜在取不同曲率时形成的基频光腰斑半径,及凹面镜在不同的入射角度下引起的像散,最终确定两凹面镜的曲率半径均为100 mm,其入射角度小于3°,以提高倍频效率。改进冷却和控温系统,并选取掺杂浓度较低(0.6 at.-%)的Nd:YAP激光晶体,以降低激光介质的热透镜效应。在光抽运功率为10 W,稳频伺服系统运转下,绿光和红外光的输出功率分别为1.02 W和700 mW,频率稳定性优于±484 kHz和±240 kHz,功率波动小于±0.65%和±0.5%。

A continuous laser-diode end-pumped Nd:YAP/KTP laser with dual wavelength outputs at 0.54 μm and 1.08 μm has been achieved. The ring laser resonator consists of five mirrors and a piece of frequency-doubling crystal KTP is placed between two concave mirrors. After calculating and comparing the waist-sizes of the fundamental wave and the astigmatism at different incident angles to the concave mirrors, the curvature radii of the concave mirrors as 100 millimeter are chosen and the incident angles of infrared light are less than 3 degree. The cooler and temperature controller of Nd:YAP rod are improved and the lower dopant concentration of the Nd:YAP (0.6 at.-%) is chosen, thus the thermal effect of the laser rod is decreased. Under a pump power of 10 W, the output powers for the second-harmonic wave and the fundamental wave of 1.02 W and 700 mW are simultaneously obtained with the intensity fluctuations less than ±0.65% and ±0.5%, respectively. With the frequency-stabilizing servo system on, the frequency stabilities for 0.54 μm and 1.08 μm wavelengths are better than ±484 kHz and ±240 kHz, respectively.