Single-mode fiber to GRIN-rod lenses coupling efficiency and tolerance analysis

Abstract

The single-mode fiber coupling efficiency with graded-index rod lenses can achieve higher coupling efficiency, compared with the direct alignment coupling of the single-mode fiber. The assembly error of direct alignment has a far greater impact on the coupling efficiency of the fiber than the GRIN lenses coupling to fiber. The analysis of the influence of the coupling error on the optical fiber coupling efficiency provides important theoretical support and guidance for processing and assembly. Axial error, radial error and angular tilt will all have different effects on fiber coupling efficiency. However, the fiber coupling system is not only limited to the coupling of the fiber and GRIN lenses, but also can be coupled with one or more lenses to analyze the advantages and disadvantages of multiple coupling methods.