Choubey Ambar, Vishwakarma S C, Misra Pushkar, Jain R K, Agrawal D K, Arya R, Upadhyaya B N, Oak S M
Solid State Laser Division, Raja Ramanna Centre for Advanced Technology, Indore, Madhya Pradesh 452013, India.
Rev Sci Instrum. 2013 Jul;84(7):073108. doi: 10.1063/1.4812635.
We have developed an efficient and high average power flash lamp pumped long pulse Nd:YAG laser capable of generating 1 kW of average output power with maximum 540 J of single pulse energy and 20 kW of peak power. The laser pulse duration can be varied from 1 to 40 ms and repetition rate from 1 to 100 Hz. A compact and robust laser pump chamber and resonator was designed to achieve this high average and peak power. It was found that this laser system provides highest single pulse energy as compared to other long pulsed Nd:YAG laser systems of similar rating. A slope efficiency of 5.4% has been achieved, which is on higher side for typical lamp pumped solid-state lasers. This system will be highly useful in laser welding of materials such as aluminium and titanium. We have achieved 4 mm deep penetration welding of these metals under optimized conditions of output power, pulse energy, and pulse duration. The laser resonator was optimized to provide stable operation from single shot to 100 Hz of repetition rate. The beam quality factor was measured to be M(2) ~ 91 and pulse-to-pulse stability of ±3% for the multimode operation. The laser beam was efficiently coupled through an optical fiber of 600 μm core diameter and 0.22 numerical aperture with power transmission of 90%.
我们研制了一种高效、高平均功率的闪光灯泵浦长脉冲Nd:YAG激光器，其平均输出功率可达1kW，单脉冲能量最大为540J，峰值功率为20kW。激光脉冲持续时间可在1至40ms之间变化，重复频率在1至100Hz之间。设计了一个紧凑且坚固的激光泵浦腔和谐振器，以实现这种高平均功率和峰值功率。结果发现，与其他类似功率的长脉冲Nd:YAG激光系统相比，该激光系统具有最高的单脉冲能量。实现了5.4%的斜率效率，这在典型的灯泵浦固态激光器中处于较高水平。该系统在铝和钛等材料的激光焊接中将非常有用。在输出功率、脉冲能量和脉冲持续时间的优化条件下，我们已实现了这些金属4mm深的穿透焊接。对激光谐振器进行了优化，以确保从单次发射到100Hz重复频率的稳定运行。在多模运行中，测量的光束质量因子M(2)约为91，脉冲间稳定性为±3%。激光束通过一根芯径为600μm、数值孔径为0.22的光纤实现了高效耦合，功率传输率为90%。
