偏斜光线抽运下的回音壁模式光纤激光辐射特性

Radiation properties of a whispering-gallery-mode fibre laser based on skew light pumping

研究了偏斜光线抽运下的回音壁模式光纤激光辐射特性.实验发现,在抽运光以偏斜光线方式沿光纤的近轴向抽运时,回音壁模式的光纤激光辐射中,既存在光电矢量和光纤径向垂直的横电波(TE),也存在光电矢量和光纤径向平行的横磁波(TM);随增益包层染料溶液折射率的增加,径向模式数和角模式数相同的TE波和TM波之间的波长差单调减小,回音壁模式激光辐射的中心波长向短波方向移动,辐射的波长范围变窄.用回音壁模式激光的辐射理论结合激光染料的四能级模型,满意地解释了实验结果.

The radiation properties of a whispering-gallery-mode （WGM） fibre laser based on skew beam pumping have been studied. It is found from experiment that when pumped by skew light along the fibre’s axis, both transverse electric wave （TE） a nd transverse magnetic wave （TM） exist in WGM lasing emission simultaneitly. Wit h the increase of refractive index of cladding dye solution, the wavelength spacing between TE and TM waves of which the radial mode number and angular mode number are the same value decreases, and the central lasing wavelength of WGM bluely shifts to short wavelength direction. Based on radiation theory of WGM fibre laser and a model of four-energy levels of dye laser, the obtained experimental results are well explained.