机械感生长周期光纤光栅的可调谐环形光纤激光器

将采用机械感生法写制的长周期光纤光栅(MLPFG)串入环形腔中,设计了一种新颖的L波段可调谐环形掺铒光纤激光器(EDFL)。抽运光源为980nm半导体激光器,使用掺铒浓度为5×10-4,长度为12m的铒纤作为增益介质,通过调整待写制光纤与周期性压力槽之间的夹角,改变MLPFG的写制周期,调谐MLPFG透射谱,进而影响环形腔增益最高点,光纤激光器波长可调谐范围可达42nm(1562.465～1604.280nm),激光光谱3dB带宽0.04nm,20dB带宽0.08nm,边模抑制比45dB。长时间观测表明,激光功率稳定性优于0.2dBm。实验显示,该光纤激光器具有带宽较宽,线宽较窄及性能稳定等特点。

Tunable Ring Fiber Laser Using Mechanical-induced Long-period Fiber Gratings

A tunable L-band ring Er~(3+)-doped Fiber Laser (EDFL) with Mechanically-induced Long-period Fiber Grating (MLPFG) is reported,in which a 980 nm Laser Diode (LD) is used as pump source, and a 5×10~(-4) highly Er~(3+) -doped fiber is used as its gain medium. The optical fiber laser with a wavelength-tunable range of 42 nm(1 562.465-1 604.280 nm)is achieved by adjusting MLPFG fabricated period and altering the angle between fiber and grooved pressure plat. The 3 dB line-width and the 20dB line-width of the laser are less than 0. 04 nm and 0.08 nm respectively, while the Side Mode Suppression Ratio (SMSR) is more than 45 dB. Moreover, the power stability of the laser is better than 0.2 dBm for a prolonged observation. Experimental results show that the tunable EDFL has advantages of wide bandwidth, narrow line-width and stable performance.