基于PM-FBG的可开关双波长掺铒光纤激光器

Switchable Dual-wavelength Erbium-doped Fiber Laser Based on a Polarization Maintaining Fiber Bragg Grating

利用保偏光纤光栅(PM-FBG)设计了一种线性腔可开关双波长掺铒光纤激光器。由于与保偏光纤光栅两个反射峰对应的激射双波长的两纵模在偏振态上是正交的,在均匀展宽的掺铒光纤中增强的偏烧孔(PHB)效应减小了不同模式间的竞争,因此可在常温下得到稳定的双波长。另外,通过调整偏振控制器的状态,可使激光器在稳定的双波长状态或在两波长之间转换。实验结果表明,在100 mA的泵源电流抽运下,双波长同时激射时的激光消光比大于36 dB,室温下激光工作稳定,5 h内,激射激光双波长基本无变化,峰值抖动小于0.06 dB。最后验证了泵源驱动电流与激射光谱的关系。

A switchable dual-wavelength erbium-doped fiber laser with the linear cavity using a polarization maintaining fiber Bragg grating has been designed.Dual-wavelength laser operates on two longitudinal modes.The birefringence induced by the FBG is beneficial to diversify the polarization states of different wavelength in the EDF and enhance the polarization hole burning（PHB） effect.This PHB greatly increased the inhomogeneous gain broadening of EDF and accordingly reduced the wavelength competition.Thus,it is possible to achieve stable dual-wavelength oscillations at room temperature.On the other hand,through adjusting the state of the polarization controller（PC）,the mode selection is achieved in laser oscillation and the laser can be designed to operate in wavelength switching modes.It is demonstrated that the optical noise to signal ratio（ONSR） of the dual-wavelength laser is lager than 36 dB under the 100 mA pump current.The amplitude variation over 5 h is less than 0.06 dB,and the wavelength keep stable.Finally,the relation between the pump current and the output spectra is verified.