Chattopadhyay Amit K, Nasiev Diar, Sugavanam Srikanth, Tarasov Nikita, Churkin Dmitry V
Aston University, Mathematics, Birmingham, B4 7ET, United Kingdom.
Aston University, Aston Institute of Photonic Technologies, Birmingham, B4 7ET, United Kingdom.
Sci Rep. 2016 Jun 28;6:28492. doi: 10.1038/srep28492.
Loss of coherence with increasing excitation amplitudes and spatial size modulation is a fundamental problem in designing Raman fiber lasers. While it is known that ramping up laser pump power increases the amplitude of stochastic excitations, such higher energy inputs can also lead to a transition from a linearly stable coherent laminar regime to a non-desirable disordered turbulent state. This report presents a new statistical methodology, based on first passage statistics, that classifies lasing regimes in Raman fiber lasers, thereby leading to a fast and highly accurate identification of a strong instability leading to a laminar-turbulent phase transition through a self-consistently defined order parameter. The results have been consistent across a wide range of pump power values, heralding a breakthrough in the non-invasive analysis of fiber laser dynamics.
随着激发幅度和空间尺寸调制增加而出现的相干性丧失是设计拉曼光纤激光器时的一个基本问题。虽然已知提高激光泵浦功率会增加随机激发的幅度，但这种更高的能量输入也可能导致从线性稳定的相干层流状态转变为不理想的无序湍流状态。本报告提出了一种基于首次通过统计的新统计方法，该方法对拉曼光纤激光器中的激光模式进行分类，从而通过自洽定义的序参量快速且高精度地识别导致层流-湍流相变的强烈不稳定性。结果在很宽的泵浦功率值范围内都是一致的，这预示着光纤激光动力学无创分析方面的一项突破。
