808nm高亮度半导体激光器光纤耦合器件

针对单个808nm单管半导体激光器输出功率低,采用端面泵浦方式对光纤激光器进行泵浦时受到限制的问题,本文利用空间合束技术制成高亮度半导体激光器光纤耦合模块来提高808nm单管半导体激光器泵浦掺Nd3+双包层光纤激光器的效率。首先,通过微透镜对每个单管半导体激光器进行快慢轴准直;然后,使用反射棱镜对每个激光器发出的光进行空间合束;最后,利用自行设计的扩束系统将合束后的光束进行扩束,聚焦进入光纤,从而极大地提高光纤耦合模块的亮度。实验中将4只连续输出功率为5W的单管半导体激光器发出的光束耦合进芯径为105μm、数值孔径(NA)为0.2的光纤,当工作电流为5.8A时,通过光纤输出的功率为15.22W,耦合效率达到74%,亮度超过1.4MW/cm2.sr。

808 nm high brightness module of fiber coupled diode laser

As 808 nm single emitter diode lasers have low output powers,they are limited to pump neodymium-doped double-cladding fiber lasers in end pumping. In order to enhance the pumping efficiency of the fiber laser by using single emitters,a fiber coupled module with several single emitter diode lasers was developed. First, the fast axis and slow axis of each diode laser were collimated by a micro-lens. Then, the output beams of diode lasers were combined with reflecting prisms. Finally, a suit of optical system designed by ourselves was utilized to expand and focus the beam into a optical fiber. Experiments show that this approach can greatly increase the brightness of the module with fiber coupled LDs. Four LDs with continuou output power of 5 W are coupled in a 105 μm multimode optical fiber with a core diameter of 105 μm and a numerical aperture of 0.2 when the working current is 5.8 A,it can offer the fiber output power of 15.22 W, coupling efficiency of 74% and the brightness over 1.4 MW/cm2·sr.