双光纤光栅外腔半导体激光器相干失效研究

Coherence collapse of the dual fiber Bragg grating external cavity semiconductor laser

根据双光纤Bragg光栅（FBG）外腔半导体激光器相干失效的物理过程,运用速率方程和双FBG耦合模理论,分析了双FBG外腔半导体激光器相干失效产生和控制的条件,提出了实现和控制双FBG外腔半导体激光器相干失效多模稳定工作的方法.双FBG外腔半导体激光器在相干失效下具有多模的稳定工作状态,相干失效长度缩短,相干失效长度内光谱稳定.实验测量结果表明,外腔反射率为3%时,从非相干失效状态到相干失效状态,半峰值全宽度从0.5 nm突然展宽到0.9 nm.在相干失效状态下,功率稳定,边模抑制比大于45 dB,在0℃~C一70℃工作温度范围内峰值波长漂移小于0.5 nm,最小相干失效长度小于0.5 m.双FBG外腔半导体激光器相干失效的应用对提高光纤放大器和光纤激光器的性能具有重要意义.

The preconditions and controlling factors of coherence collapse（CC） are analyzed by the rate equations and dual fiber Bragg grating（FBG） couple mode theory based on the physical process of dual FBG external cavity semiconductor lasers.A method of achieving and controlling CC multi-mode stable state is put forward for dual FBG external cavity semiconductor lasers.When the dual FBG external cavity semiconductor laser operates at the multi-mode stable state under the CC regime,the CC length reduces.The spectrum of the laser is relatively stable within the CC length.The experimental results show the output power of the laser is stable while the laser with the 3%external reflectivity is operating under the CC regime.The side mode suppression ratio is more man 45 dB. The full wave at half maximum broadens from 0.5 nm to 0.9 nm dramatically as soon as the laser operates from the incoherence collapse regime to the CC regime.The wavelength shift is less than 0.5 nm at the operating temperature of 0℃—70℃.The minimum of the CC length is less than 0.5 m.The CC application of dual FBG external cavity semiconductor lasers is vital to improve the performance of optical fiber amplifiers and fiber lasers.