Microlens fabrication on single-mode fibres for efficient coupling from laser diodes

摘要

An analysis of the etching process for forming a truncated conical microlens on the end surface of a single-mode fibre (SMF) so as to improve its coupling efficiency with a laser diode (LD) has been carried out. This is followed by a simple geometric-optics and electromagnetic analysis to calculate this coupling efficiency, when the lens is formed on a SMF fabricated by the MCVD technique. The theory is supported by measurements which gave a maximum coupling efficiency of 57.