Monolithic Integrated Ingaalas/Inp Ridge Waveguide Photodiodes

The application of the InGaAlAs/InP material system to low loss waveguides and monolithically integrated waveguide photodiodes for opto-electronic integrated circuits is described. Low loss waveguiding was obtained on ridge waveguides at 1.3 and 1.55 μm and then applied on the monolithic integration of a ridge waveguide with an InGaAs pin photodiode for detection at 1.55 μm wavelength. The structure was entirely grown by molecular beam epitaxy on a InP substrate. Absorption of the guided light is provided by leaky coupling from the InGaAlAs guiding layer into the higher index InGaAs absorbing layer. External quantum efficiencies as high as 20% have been obtained. This is the first demonstration of a monolithic integrated waveguide device in the InGaAlAs/InP material system.