LD泵浦不同腔结构高效运转掺铥光纤激光器(英文)

LD clad-pumped high efficient Tm-doped fiber lasers with different laser cavities

研究了掺铥光纤激光器的不同谐振腔结构方式。使用LD泵浦,分别采用双色镜和端面反射、高反光纤光栅和端面反射以及双色镜和低反光纤光栅构成激光器谐振腔,均获得了超过Stokes极限的斜效率。其中双色镜和端面反射腔结构下获得了最高斜效率56.9%,对应的量子效率为142%。三种腔结构下,激光光谱线宽由激光器系统所采用的反射腔的光谱特性所决定。在双色镜和端面反射腔结构下,激光器在双色镜的高反带宽内随机起振,光谱较宽;在使用光纤布拉格光栅作为激光器谐振腔的高反射腔镜和低反射腔镜的情况下,激光器都获得了2μm处的窄线宽输出,线宽受限于所使用的光纤光栅的反射带宽。

LD clad-pumped high efficient Tm-doped fiber lasers with quantum efficiencies beyond the Stokes Limit were reported. Different laser cavities, including dichroic mirror with fiber end reflection, high reflective fiber Bragg grating （FBG） with fiber end reflection and dichroic mirror with low reflective FBG, were studied. A maximum slope efficiency of 56.9% was obtained with the dichroic mirror and the fiber end flection forming the laser cavity, corresponding to a quantum efficiency of 142%. Spectral linewidth of the laser output was closely related to the reflective mirrors used in different cavities. Selected by the broadband dichroic mirror, the laser resonated randomly with the high reflective band of t he dichroic mirror. With an FBG as the high reflective mirror of the laser cavity, narrow linewidth of 38 pm was attained at an output of 1 W. In another laser configuration, one low reflective FBG was exploited as the output coupler, and narrow linewidth of 69 pm was achieved at an output of 0.9 W. And the laser linewidth was limited by the reflection bandwidth of the FBG used.