Design and Optimization of a Single-mode Fiber Double Gaussian Coupling Lens

Aiming at the problem that large aberrations reduce the coupling efficiency of spherical lens coupling into single mode fiber,a method of using double Gaussian lens as a coupling lens to eliminate aberrations and improve coupling efficiency is proposed. By using the special structure of the double Gauss lens,a spherical lens can eliminate most of the aberrations including spherical aberration,and reduce the influence of lens aberration on the coupling efficiency. We designed and optimized a dual Gaussian coupling lens for 780nm wavelength 5 micron mode field diameter single mode fiber by ZEMAX. The evaluation function of the system aberration and the coupling efficiency were calculated to reach the order of 10^-5 and 82.07% respectively. The article provides a new idea for the design and use of single-mode fiber-coupled lens.