DIODE-LASER-TO-WAVE-GUIDE BUTT COUPLING - EXTREMELY SHORT EXTERNAL-CAVITY

An ultrashort composite cavity (less than or equal to 10 mu m in lengt h) laser diode was used to verify experimentally a butt-coupling model that considers interference inside the external cavity and its influe nce on laser operation. The fine structure of an experimental coupled power versus laser-to-fiber separation curve is explained when a compl ex coupling coefficient is introduced into the model. The importance o f the phase term of this coefficient and regions of validity of the mo dified butt-coupling model are also discussed. (C) 1997 Optical Societ y of America.