MBE Growth and Processing of InGaAs/InGaAlAs/InP Monolithical Integrated Ridge Waveguide Photodiodes

The molecular beam epitaxial growth of high quality InGaAlAs/InP and its application to low loss passive optical waveguides and waveguide-integrated photodiodes for operation at 1.55 ¿m is described. The chemical etching characteristics of the layers were optimized in order to fabricate low loss (2.2 dB/cm) ridge waveguides. Integration of the waveguides with an InGaAs pin photodiode is demonstrated using absorption of the guided light by leaky coupling from the InGaAlAs guiding layer into the higher index InGaAs absorbing region containing a p/n junction. The devices showed external quantum efficiencies as high as 20% for operation at 1.55 ¿m wavelength. This is the first demonstration of a monolithic integrated waveguide device in the InGaAlAs/InP material system.