Microlens tipped on a single-mode fibre end for InGaAsP laser coupling improvement

Abstract

A new fabrication method for a hemispherical microlens on optical fibre ends is proposed, to achieve high coupling efficiency between an InGaAsP laser with a buried heterostructure geometry and a single-mode fibre. The microlens is fabricated by attaching silica glass to the fibre end, which is then heated to form the desired shape by electric discharge. The lowest coupling loss of 2.9 dB has been achieved by selecting the optimum lens radius at 8.5 μm. Effects of misalignment are also reported.