双波长环形腔掺铒光纤激光器输出的稳定性

Output Power Stability of Dual-Wavelength Erbium-Doped Fiber Ring Laser

使用掺铒光纤平均反转粒子数模型推导了双波长激光器平衡振荡需满足的条件,并据此设计实验系统,对抽运功率、模式损耗以及波长间隔对输出功率的影响进行了实验研究。结果表明,可通过调节腔内损耗谱实现掺铒光纤环形腔内多波长激光输出,双模平衡振荡条件在远离阈值点情况下成立;可变衰减器的稳定性对双波长平衡的影响极大,允许的偏离值小于0.4 dB;而起振波长的偏离对双波长平衡的影响较小,大于1 nm的波长偏离才会导致平衡破坏;掺铒光纤的非均匀加宽效应允许平衡时损耗在一定范围内波动,这有助于提高激光器的输出稳定性,30 min内1546 nm和1556 nm双波长的功率波动小于0.5 dB。

The condition for equilibrium oscillation of dual-wavelength erbium-doped fiber ring laser is derived from the average inversion level model. According to this condition, a novel experiment setup is built to measure the influence of pump power, mode losses and wavelength interval on the output power. Experiment results show that the multi-wavelength oscillation in erbium-doped fiber ring laser can be achieved by adjusting the loss spectrum of laser cavity, and the condition for equilibrium oscillation is valid when pump power is far away from the threshold point. The stability of variable optical attenuator has so great influence on the balance of dual-wavelength whose acceptable loss bias is less than 0.4 dB. However the stability of central wavelength of fiber Bragg grating （FBG） has little influence on the balance of dual-wavelength which won＇ t be broken by the wavelength bias less than 1 nm. Inhomogeneous effect of erbium-doped fiber allows tiny perturbation of the loss in state of equilibrium, which is helpful to improve the stability of the laser output power, and the power fluctuation of 1546 nm and 1556 nm over 30 minutes is less than o. 5 dB.