激光二极管侧面抽运声光调QNd∶YAG/KTA 1.57μm人眼安全光参量振荡激光器

利用激光二极管(LD)阵列侧面抽运声光(AO)调Q的Nd∶YAG激光器作为抽运源,研究了在不同声光重复频率和输出镜透过率的情况下,内腔式KTA-光参量振荡器(OPO)的输出特性。通过对单谐振光参量振荡器阈值公式的讨论,采用平凹腔的结构以及较短的腔长,降低了光参量振荡器的振荡阈值。当声光重复频率为4 kHz,输出镜透过率为30%,抽运电流为14.5 A时,光参量振荡器的1570 nm激光输出脉冲峰值功率达到5.6×104W,脉冲宽度为2.5 ns,实验中最大平均输出功率为560.3 mW。结果表明,具有良好热性能的非线性晶体KTA是制造小型、轻便光参量振荡激光器的理想材料。

Laser Diode-Side-Pumped Acousto-Optic Q-Switched Nd∶YAG/KTA Eye-Safe Optical Parametric Oscillator

An intracavity KTiOAsO4 (KTA) optical parametric oscillator (OPO) pumped by a laser diode array side-pumped, acousto-optically (AO) Q-switched Nd∶YAG laser is investigated. The output performance of KTA-OPO is tested at different repetition rates and transmissions of the output mirror. Through discussion of the threshold formula of the singly resonant OPO, a plane-concave cavity and a short OPO cavity length are employed to decrease the OPO′s pumping threshold. The parameters of output laser have been measured at different repetition rates and transmissions of the output mirror. When the repetition rates of acousto-optic Q-switch and transmission of output mirror are 4 kHz and 30% respectively, the output peak power of 1570 nm wavelength reaches 5.6×104 W with the pulse width of 2.5 ns. The highest average output power of 560.3 mW is obtained. KTA is a kind of ideal material used to make pocket and portable OPO laser.