Abstract

Stable, efficient, and reflection-free optical coupling is a key issue for optical telecommunication devices.¹ Especially in semiconductor optical amplifiers (SOAs), two-port coupling is required, and the optical coupling efficiency determines their effective noise figure and effective output power as well as their net gain. We have reported SOA modules using twin GRIN rod lenses in which −4.5 dB/facet coupling efficiency is achieved.² The optical beam divergence is as wide as −55° for a polarization-insensitive SOA chip, and the coupling efficiency is mainly limited by the wavefront aberration and the numerical aperture (N.A.) of the lens next to the SOA.

© 1992 Optical Society of America