D形双包层大模场光纤激光偏振特性研究

Research on the polarization characteristics of D-shape large mode area double-clad fiber laser

为了考察双包层光纤激光器的偏振行为,选用国产大模场D型内包层光纤,采用单端抽运的方法,测量了不同缠绕半径和不同抽运强度下光纤输出激光的偏振态。结果表明,激光器在阈值附近单波长运转时,如果光纤缠绕半径较小,输出激光表现出较明显的偏振特征,如果缠绕半径较大,输出激光偏振特征较弱;高于阈值多波长运转时,无论采用何种缠绕半径,都观测不到偏振现象。

To investigate the polarization property of a double-clad fiber（DCF） ,the polarization states of a home made D-shape DCF laser at different coiling radii and pump powers were measured under the condition of one end pump. Results show that when the laser operates at a single wavelength around the threshold level ,the output laser shows clear evidence of polarization at a small coiling radius and that the polarization behavior of output laser is relatively weak at a large coiling radius. When the laser operates at multiwavelengths above threshold power,there is no sign of polarization for the output laser independent of the coiling radius.