Abstract

Monolithic optoelectronics requires optical linkage between waveguides and photodiodes. Vertical coupling offers the advantages of single-step epi-growth and ease of junction placement.^1,2 Its drawback is weak coupling, resulting in long detector lengths L and high capacitance. thinner guides can reduce L,^1,2 but increase input coupling difficulty. We recently demonstrated than an optical "matching layer' introduced between a thick n^-/n^+ InP waveguide and an InGaAs absorber significantly enhances vertical coupling.³ Here we show that this approach provides efficient coupling between InGaAs detectors and InGaAsP waveguides of the type currently employed in photonic integration.

© 1991 Optical Society of America