Photodetectors monolithically integrated with optical waveguides: theoretical and experimental study of absorbing layer effects

The authors present a model for the study of photodetectors monolithically integrated with optical waveguides. They have investigated how an absorbing layer influences the propagation constants of the modes of optical waveguides, by developing a four layer model with refractive indices in each layer. Comparisons with experimental results obtained with devices made in their laboratory and elsewhere show a good agreement. They have used this model to predict and fabricate a short length GaInAs photoconductor monolithically integrated with GaAs/GaAlAs waveguide on GaAs semi-insulating substrate. Experimental results are analysed using this model.<>