基于偏振折叠的光纤耦合实验研究

Experimental study on fiber coupling based on polarization folding

基于二极管激光器mini-bar的光纤耦合方式是一种降低耦合系统成本并提高整体转换效率的方法。提出一种偏振折叠的光束整形方式,并采用一种CW 50 W mini-bar进行了相关耦合系统的设计。针对mini-bar的特殊结构与散热需求,设计了针对mini-bar封装用的特种微通道冷却器,并通过封装实验结果验证设计有效。将10片封装在铜微通道冷却器上的CW 50W mini-bar组装成两列各5 bar的叠阵,实现了两列叠阵的激光束沿快轴方向的空间合成,合成后输出功率439 W,空间耦合效率97%。根据耦合系统的设计进行了400μm芯径、0.22 NA的光纤耦合实验,得到光纤输出端脉冲激光功率186.9 W,整体光光效率为52.2%。

Fiber coupled system based on mini-bar is an effective way for avoiding complex beam shaping to reduce the costs and improve brightness. A beam shaping method named polarization folding is designed to reduce BPP of slow axis to a half, and the fiber coupling scheme based on polarization folding is also given. A microchannel heatsink is designed for the special demand of mini-bar package, and it had been proved according to the result of packaging ex- periment. 439 W output power of mini-bar spatial coupling module and 97% spatial coupling efficiency are achieved by spatial coupling of two 5 mini-bar stacks. A peak power of 186. 9 W is achieved in the fiber coupling experiment, the O-O efficiency is about 52. 2%.