Abstract

Coupling losses between optical devices in communication systems remain a high point in overall system performance. It is difficult to efficiently couple large optical source beam size to small diameter transmission fibers (single mode fibers, SMF). Traditional coupling techniques (lens, lensed fibers, etc.) require an intermediate device to increase the coupling efficiencies, but remain dependent on proper alignment with the SMF. The novel design of an all-optical multimode-to-single mode taper is studied to meet this problem. The large diameter (50 µm) of the MMF allows flexibility in alignment while the tapering region adiabatically confines the light beam to the size of the SMF (9 µm). Three-dimensional simulations using the Finite-Difference (FD) Beam Propagation Method (BPM) are carried out to optimize the coupling efficiency of the device.

© 2003 Optical Society of America