摘要
增益光纤的折射率和离子掺杂分布是决定光纤激光器输出功率和光束质量的重要因素,针对大模场光纤弯曲效应对模场面积和模场畸变的影响进行了数值分析,采用有限元方法计算了不同折射率和掺杂离子分布光纤的模场面积和增益系数。提出了高斯复合型折射率和掺杂离子分布的大模场增益光纤结构,该结构可有效提高增益光纤的增益系数和高阶模抑制系数,并具有较强的抗弯曲特性,较好的平衡了模场面积与抗弯曲特性的矛盾。根据计算结果设计了直径为65μm的高斯复合型折射率和掺杂分布的增益光纤,在波长为1.064μm的条件下,基模有效模面积达到1.17×103μm2,基模相对增益系数和高阶模相对抑制系数分别达到0.58和0.2088,有效地提高了光纤激光器和放大器的输出光束质量。
The gain fiber is the important indicators to determine the output power and beam quality of fiber laser. The paper focused on the large-mode-area fiber （LMA） bending effect on fundamental mode （FM） area and mode field distortion by numerical analysis, the FM area and gain coefficient of LMA fiber with different refractive index （RI） and doped distributions were solved by finite-element method. The Gaussian hybrid refractive index distribution and doping profile were proposed firstly. It can effectively improve the gain coefficient and suppression coefficient of high-order modes （HOMs）. Moreover, the bending against of the fiber can be strengthen, the design can balance the contradiction the mode area and bending resistance. Based on the numerical calculation, the gain fiber with Gaussian hybrid RI distribution and doping profile were designed, the fiber diameter was 65μm. At the wavelength of 1.064μm, the FM area can be 1.17×103μm2, the FM relative gain coefficient and relative suppressing coefficient can reach 0.58 and 0.208 8, the output and beam quality of the fiber laser can be improved effectively.
出处
《红外与激光工程》
EI
CSCD
北大核心
2014年第9期3051-3056,共6页
Infrared and Laser Engineering
基金
国家自然科学基金
关键词
高斯复合型分布
模场面积
相对增益系数
高阶模相对抑制系数
Gaussian hybrid distribution
mode area
relative gain coefficient
relative high-order modes suppressing coefficient
