Optical measurement of effective recombination lifetime in silicon epitaxial layers

In this letter we present a novel all-optical pump-probe technique for the measurement of effective recombination lifetime in silicon epitaxial layers. The procedure is based on the measurement of the variation of the attenuation coefficient due to optically injected free carriers of a planar dielectric waveguide defined by the epitaxial layer cladded between the substrate and the air. Perturbation theory is used to take into account nonuniform refractive index distribution due to nonzero surface recombination. The measurement technique is validated by both numerical simulation and experimental results. (C) 1997 American Institute of Physics.