Liu Bin, Wang Bo, Ruan Yuxi, Yu Yanguang
Opt Express. 2022 Mar 28;30(7):11254-11265. doi: 10.1364/OE.453563.
Undamped relaxation oscillation (RO) in a laser self-mixing interferometry (SMI) system may occur in some common application conditions, which may impact the stable operation of the system and degrade its sensing performance. In this work, we proposed to suppress the undamped RO by controlling the system operation parameters in a laser SMI sensing system. By numerically solving the famous Lang Kobayashi equations, the stability of a laser SMI system in a 3-parameter space of external cavity length, injection current and optical feedback factor were investigated. Based on the stability analyses, we determined the system operation conditions required for suppressing the undamped RO and derived an analytical expression for describing the relationship between the operation parameters. An experimental SMI system based on a laser diode (Sanyo, DL4140-001s) was implemented and verified the suppressing method. The experimental results showed that the SMI system in a moderate feedback regime can operate in steady state without undamped RO by setting proper operation parameters. This work provides useful guidance to design a stable SMI sensing system for practical applications.
在激光自混合干涉测量（SMI）系统中，无阻尼弛豫振荡（RO）可能会在一些常见应用条件下出现，这可能会影响系统的稳定运行并降低其传感性能。在这项工作中，我们提出通过控制激光SMI传感系统中的系统运行参数来抑制无阻尼RO。通过对著名的朗 - 小林方程进行数值求解，研究了激光SMI系统在外部腔长、注入电流和光反馈因子的三参数空间中的稳定性。基于稳定性分析，我们确定了抑制无阻尼RO所需的系统运行条件，并推导了描述运行参数之间关系的解析表达式。搭建了基于激光二极管（三洋，DL4140 - 001s）的实验性SMI系统，并验证了该抑制方法。实验结果表明，通过设置适当的运行参数，处于适度反馈区域的SMI系统可以在无无阻尼RO的情况下稳定运行。这项工作为设计用于实际应用的稳定SMI传感系统提供了有用的指导。
