Fiber coupled diode laser beam parameter product calculation and rules for optimized design
Fiber coupled diode laser beam parameter product calculation and rules for optimized design
复制标题
光纤耦合二极管激光束参数乘积计算及优化设计规则
DOI：
--
复制
发表时间：
2011
期刊：
影响因子：
--
通讯作者：
R. Pandey
中科院分区：
文献类型：
--
作者：
Zuolan Wang;S. Drovs;Armin Segref;T. Koenning;R. Pandey
无源无损耗系统的光束参数乘积（BPP）是常数，并且不能被改进，但是光束可以被重新成形以增强耦合性能。光纤耦合二极管激光器光学设计师的作用是保持二极管光源的亮度，同时最大限度地提高耦合效率。在将二极管激光器功率耦合到光纤输出中时，光纤芯的对称几何形状使得非常希望在光纤输入表面处具有对称的BPP，但这并不总是实用的。因此，在详细设计和仿真过程之前，期望能够使用快轴和慢轴的BPP来知道“对角线”（光纤）BPP。已经发现，用于此目的的常用表达式，即，在快轴和慢轴上的BPP的平方和的平方根，一致地低估了光纤BPP（即，预测的光束质量比实际上可实现的光束质量更好）。在本文中，使用一个简化的模型，我们提供了正确的计算的对角线（即纤维）BPP使用的BPP的快，慢轴作为输入的证明。使用相同的简化模型，我们还提供了证明，光纤BPP可以显示出具有最小（最佳）值给定二极管BPP和这个优化的条件，可以得到任何详细的设计和仿真之前进行。测量和模拟数据证实了二极管的BPP和预测的光纤BPP之间的良好相关性。
The Beam Parameter Product (BPP) of a passive, lossless system is a constant and cannot be improved upon but the beams may be reshaped for enhanced coupling performance. The function of the optical designer of fiber coupled diode lasers is to preserve the brightness of the diode sources while maximizing the coupling efficiency. In coupling diode laser power into fiber output, the symmetrical geometry of the fiber core makes it highly desirable to have symmetrical BPPs at the fiber input surface, but this is not always practical. It is therefore desirable to be able to know the 'diagonal' (fiber) BPP, using the BPPs of the fast and slow axes, before detailed design and simulation processes. A commonly used expression for this purpose, i.e. the square root of the sum of the squares of the BPPs in the fast and slow axes, has been found to consistently under-predict the fiber BPP (i.e. better beam quality is predicted than is actually achievable in practice). In this paper, using a simplified model, we provide the proof of the proper calculation of the diagonal (i.e. the fiber) BPP using BPPs of the fast and slow axes as input. Using the same simplified model, we also offer the proof that the fiber BPP can be shown to have a minimum (optimal) value for given diode BPPs and this optimized condition can be obtained before any detailed design and simulation are carried out. Measured and simulated data confirms satisfactory correlation between the BPPs of the diode and the predicted fiber BPP.