基于全光纤滤波技术的多波长掺铥光纤激光器

Multi-wavelength Tm-doped fiber laser based on all fiber filtering technology

设计了一种基于马赫-曾德和光纤光栅滤波结构的掺铥光纤激光器,实现了2μm波段多波长激光输出。马赫-曾德滤波器由2个3 d B耦合器构成,光纤光栅反射波长为1950.35 nm,滤波器的波长间隔为1.6 nm,激光器阈值为70m W。通过实验证明了采用马赫-曾德结合光纤光栅进行滤波能够有效提高波长稳定性,实验中通过调节偏振控制器能够实现稳定的单波长、双波长及三波长激光输出。1892.2 nm单波长激光的波长漂移和功率漂移分别小于0.6 nm和0.969 d B,边模抑制比为49.75 d B;1902.8 nm和1932.0 nm双波长激光的波长漂移均小于0.4 nm,功率漂移分别小于1.021 d B和2.583 d B;1895.7 nm、1902.5 nm和1931.9 nm三波长激光的波长漂移分别小于0.4 nm、0.3 nm和1.0 nm,功率漂移分别小于2.548d B、1.441 d B和0.809 d B。输出激光3 d B线宽均小于0.8 nm。

A Tm- doped fiber laser based on Mach- Zehnder and FBG filter was designed,which achieved the multi- wavelength laser output around 2 μm waveband. The Mach- Zehnder filter consisted of two 3 d B couplers,and reflection wavelength of the FBG is 1950. 35 nm. The wavelength interval of filter is 1. 6 nm and the threshold value of laser is 70 m W. The experimental results show that the Mach- Zehnder filter combined with FBG can improve the stability of wavelength efficiently. In the experiment,laser output of single- wavelength,dual- wavelength and three- wavelength were obtained by adjusting the polarization controller. For 1892. 2 nm single- wavelength laser,the wavelength drift and power shift are less than 0. 6 nm and 0. 969 d B,respectively,the side- mode suppression ratio is49. 75 d B; for 1902. 8 nm and 1932. 0 nm dual- wavelength laser,the wavelength shift are both less than 0. 4 nm,the power shift are less than 1. 021 d B and 2. 583 d B,respectively; for 1895. 7 nm,1902. 5 nm and 1931. 9 nm three-wavelength laser,the wavelength shift are less than 0. 4 nm,0. 3 nm and 1. 0 nm,respectively,the power shift are less than 2. 548 d B,1. 441 d B and 0. 809 d B,respectively. The 3 d B linewidth of output laser is less than 0. 8 nm.