Vertically tapered core polymeric optical spot-size transformer

Abstract

A polymeric optical spot-size transformer (SST) with a vertically tapered core layer that enables both vertical and lateral mode expansion is described. A total fibre to waveguide insertion loss of 0.6 dB has been measured with the SST, an improvement of 2.1 dB. The 1 dB excess loss misalignment tolerance is /spl plusmn/2.7 /spl mu/m.