锥台光纤的功率转换效率研究

Power conversion efficiency of tapered fiber

锥台光纤在激光束到单模光纤以及多模光纤到单模光纤的耦合中,在一些需要质量很高光束的同时有较高功率要求的场合有广泛应用。在这些应用中,锥台光纤的功率转换效率是很重要的一个参数。介绍了锥台光纤的熔拉研磨制作方法,分析了锥台光纤的传输特性。建立了高斯近似模型,采用模场耦合理论,计算了锥台光纤的功率转换效率。在以下参数条件下对细端半径分别为(4±1)μm,(5±1)μm,(6±1)μm,(7±1)μm和(8±1)μm的锥台光纤的功率转换效率进行了实验测定,激光器输出光波长532 nm;多模光纤NA=0.11,纤芯半径a=12.5μm;得到了与理论计算吻合的结果。

Since tapered fiber works as a connector between multi-mode fiber and single-mode fiber to improve the coupling efficiency and transmits laser beam with high power and good beam quality under single-mode conditions,the power conversion efficiency of the tapered fiber is important.A method of melting and drawing tapered fiber was introduced and the transmission characteristic of tapered fiber was discussed.A Gaussian approximation model to calculate the conversion efficiency of tapered fiber was presented based on mode field coupling theory.The simulation result was discussed and an experiment was conducted with 532 nm laser,multi-mode fiber with NA=0.11,a=12.5 μm and tapered fiber with NA=0.11,a=（4±1）μm,（5±1）μm,（6±1）μm,（7±1）μm and（8±1）μm respectively,to measure the conversion efficiency of tapered fiber.The experimental results agree with the theoretical prediction.