高信噪比多波长2 μm主动锁模光纤激光器

介绍一种多波长掺铥主动锁模光纤激光器，增益介质为长2 m的掺铥光纤，主动锁模通过铌酸锂强度调制器实现。腔内加入基于双折射的光学滤波器，利用保偏光纤双折射滤波效应在滤除腔内多余超模噪声的同时，还可以实现多波长输出。基频下的锁模脉冲频谱信噪比可达68.48 dB，在稳定的锁模状态下波长信道数最大为5。此外，腔内偏振无关隔离器被替换为偏振相关隔离器后，将锁模脉冲加载数字信号同步调制，测得的眼图光信噪比提高了8.67 dB。测试结果表明，锁模脉冲的时间稳定性得到有效提升。

High SNR multi-wavelength 2μm actively mode-locked fiber laser

A multi-wavelength thulium-doped actively mode-locked fiber laser was introduced,in which the gain medium was a 2 m thulium-doped fiber,and the active mode-locking could be realized by LiNbO3 intensity modulator.An optical filter based on birefringence was added into cavity,the birefringence filter effect of polarization maintaining fiber was used to filter out the superfluous supermode noise in cavity,and also the multi-wavelength output could be realized.The mode-locked pulse frequency spectrum signal-to-noise ratio could reach to 68.48 dB at fundamental frequency,and the maximum number of wavelength channels was 5 in a stable mode-locked state.Furthermore,the polarization independent isolator in cavity was replaced by polarization dependent isolator,and mode-locked pulse was modulated by digital signal.The optical signal-tonoise ratio of eye diagram can be increased by 8.67 dB,which indicates that time stability of mode-locked pulse can be improved effectively.