Accession Number : ADP008106

Title :   Quenching of Resonantly Enhanced Absorption by Multimode Interference in Vertically-Coupled Waveguide Photodetectors,

Corporate Author : BELL COMMUNICATIONS RESEARCH INC RED BANK NJ

Personal Author(s) : Pennings, E. C. ; Deri, R. J. ; Hawkins, R. J.

Report Date : APR 1992

Pagination or Media Count : 2

Abstract : Understanding optical propagation in lossy planar waveguides is important for photonic integration. 'Steady-state eigenanalysis' , ie: an analysis using only the eigenvalues (propagation constants Beta i + j alpha i for modes i) of the complex-index stab waveguide problem, is often used to model such structures, and was recently used to optimize vertically-coupled detectors by maximizing alpha i. It predicts that alpha i can be enhanced by adjusting the absorber thickness or by inserting an additional, transparent matching layer, as indicated by a sharp resonance in the dependence of alpha i on layer thickness (fig. 2, solid curve). However, recent experiments and BPM simulations indicate that steady-state eigenanalysis fails to adequately describe devices optimized with matching layers: while enhanced absorption is observed, the predicted resonance is absent. Here we show that the resonance predicted by steady-state eigenanalysis for the conventional structure is quenched by multimode interference associated with modal power non-orthogonality, and can be accurately simulated using an eigenmode-based propagation method.

Descriptors :   *PHOTONICS, *PHOTODETECTORS, *QUENCHING, *SYMPOSIA, ABSORPTION, EIGENVALUES, INTEGRATION, INTERFERENCE, LAYERS, ORTHOGONALITY, PROPAGATION, RESONANCE, SIMULATION, STEADY STATE, WAVEGUIDES, OPTICAL PROPERTIES.

Subject Categories : Fiber Optics and Integrated Optics

Distribution Statement : APPROVED FOR PUBLIC RELEASE