基于mini-bar的光纤耦合实验研究

基于mini-bar的光纤耦合是一种进一步提高二极管激光器光纤耦合系统出光亮度的有效方法。本文对Osram公司的一款连续60 W mini-bar的发光特性进行了实验研究，选用的mini-bar在工作电流60 A时输出功率60 W，电光转换效率最大为60%，中心波长973.7 nm，慢轴发散角为9.3（1/e2）。分析了其慢轴准直的特性，了解慢轴准直透镜的选择原则。器件准直后的慢轴发散角为47.6 mrad。通过对光束参量积的计算了解到mini-bar的光束可以直接耦合进入600 m的光纤，并进行了单片mini-bar的耦合实验，得到准直系统与耦合透镜组的传输效率为83%~85%，光纤的耦合效率为86%~93%，整个系统的光光效率大于72%。

Experimental research of fiber coupling based on mini-bar

The paper investigates fiber coupling based on mini-bar. The mini-bar we packaged can deliver 60 W output power when the operating current is 60 A, and its central wavelength is 973.7 nm with the FWHM of 4.16 nm. The “smile” of this mini-bar is 0.57 μm. Analysis on the characteristic of slow axis collimation shows the principle of how to choose the appropriate slow axis collimator. The divergence of the mini-bar after slow axis collimation is 47.6 mrad. The computation of beam parameter product reveals that the output laser can be directly coupled into a fiber with the core diameter of 600 μm. Fiber coupling experiments based on the mini-bar have been performed. The transmission efficiency of collimator and fiber coupler is 83%-85%, the fiber coupling efficiency is 80%-93%, and the system optical-optical efficiency is over 72%.