1.57μm内腔式KTP光学参量振荡器

1.57 μm intracavity KTP optical parametric oscillator

为了获得1.57μm人眼安全激光输出,采用了一种声光调Q激光二极管(LD)端面抽运的Nd∶Gd VO4全固态激光器作为抽运源的人眼安全波长内腔式KTP光学参量振荡器,获得1.57μm人眼安全激光输出。在注入泵浦功率为6.33 W,重复频率为15 k Hz时,1.57μm激光平均输出功率达到405 m W,此时由二极管注入泵浦光至OPO信号光输出功率的转换效率达6.4%;在重复频率为5 k Hz时,其脉冲宽度约为2 ns,峰值功率达18.9 k W。在重复频率为15 k Hz时,信号光脉冲宽度比消耗后的泵浦光脉冲宽度压缩了13.6倍,比泵浦光脉冲压缩了16倍。实验发现1.57μm的OPO信号光输出功率随脉冲重复频率的增加而有效地增加,此类光参量振荡器有效地压缩了激光脉冲。

In order to obtain 1. 57μm eye safety laser output,an efficient intracavity optical parametric oscillator based on a KTP crystal inside an Q-switched Nd ∶ Gd VO4 laser end pumped by a fiber-coupled diode laser is adopted. In the acousto-optic Q-switched operation with the pulse repetition rate of 15 k Hz,the average power of 1. 57μm eye-safe laser is 405 m W at the incident pump power of 6. 33 W,and the conversion efficiency of the average power is 6.4% from pump diode to OPO signal output. Under the pulse repetition rate of 5 k Hz,the pulse width of 2 ns and peak power of 18. 9 k W is achieved. The signal pulse duration is about 13. 6 times shorter than that of the depleted pump light and it is about 16 times shorter than that of the pump light at a pulse repetition rate of 15 k Hz. The experimental results show that the average power of 1. 57μm OPO signal output increases effectively with the increase of pulse repetition frequency. This kind of optical parametric oscillator compresses the laser pulse effectively.