High performance asymmetric graded index coupler with integrated lens for high index waveguides

Abstract

The authors have demonstrated a planar, monolithically integrated lensed, asymmetric graded index fiber-to-waveguide coupler with 0.45dB coupling loss at 1550nm. The silicon-based coupler and the waveguides were fabricated entirely by complementary metal-oxide semiconductor compatible processes. They also observed an excellent broadband performance between 1520 and 1630nm. The average coupling loss was 0.4dB across the entire cathodoluminescence band (1530–1625nm).