基于光纤拉锥及相位调制的可切换多波长掺铒光纤激光器

研究了一种全光纤可切换多波长掺铒光纤激光器。该激光器利用一段缠绕在压电陶瓷上的单模光纤作为正弦相位调制器以及基于光纤拉锥的马赫-曾德尔干涉仪作为梳状滤波器,抑制由于掺铒光纤的均匀展宽效应引起的模式竞争,从而避免了在室温下不稳定的单波长激射,实现了多波长掺铒光纤激光器的稳定输出。实验中观察到稳定的5个波长的同时激射,相邻波长间隔为0.804 nm。信噪比大于40 dB,3 dB带宽约为0.023 nm,中心5个波长输出功率的平坦度为14 dB。同时,激光器具有灵活的波长可切换特性,通过调整驱动信号和偏振控制器的状态,实现了单波长、双波长、三波长以及更多波长的输出。该激光器可应用于大容量波分复用系统和光纤传感。

Switchable multi-wavelength fiber laser based on cascade fiber tapers and phase modulator

An all-fiber switchable multi-wavelength erbium fiber laser was proposed in this paper. A sinusoidal phase modulator composed of a piece of single-mode fiber around a piezoelectric transducer was inserted in the ring cavity, combined with an all-fiber Mach-Zehnder interferometer based on cascade in-line two-taper as the comb filter, which suppressed the mode competition owing to the homogeneous broaden line in erbium-doped fiber and eliminated the unstable wavelength lasing. Simultaneous and stable five-wavelength lasing was observed with 0.804 nm intervals at room temperature. The signal to noise ratio is higher than 40 dB, the 3 dB bandwidth is about 0.023 nm, and the five lasing lines in power differences are less than 14 dB. Meanwhile, the laser has highly flexible wavelength switchable property. By adjusting the driving signal and polarization controller, single wavelength lasing output, switchable dual, triple and ever more wavelengths lasing output could be realized. These advantages enable this laser as a potential candidate for high-capacity wavelength division multiplexing systems and mechanical sensors.