Beam Divergence from an SMF-28 Optical Fiber

摘要

We present a calculation and experimental results using three different approaches for the spatial divergence of an optical beam exiting a standard, single-mode telecommunications-grade optical fiber (SMF-28) operating near 1550 nm wavelength. The analysis shows some pitfalls for a common imaging technique for determining beam width and shows good agreement with theory when the beam width measurement is performed using either a knife-edge or pinhole approaches. These results are important for maximizing coupling efficiency between single-mode fibers and photodetectors.