Analysis of influence factors for coupling efficiency of single mode fiber

In many research fields the coupling efficiency of single mode fiber is an important issue and is influenced by some parameters. In this paper, the influence factors on coupling efficiency of single mode fiber were investigated, especially the influence of position of waist of laser beam is analyzed. For verifying these influence factors some numerical simulations were carried out. The results show that when the waist position being farther away from the laser emission system, the coupling efficiency is larger; when the waist position is located at infinite distance and the number of Airy speckles is 0, the relationship curve between the coupling efficiency and parameter a is unimodal; and also with parameter a tending towards zero the coupling efficiency is close to a bigger stable value, which differs from computation result in previous reference. These conclusions have important directive significance to the engineering design of coupling of single mode fiber.