FABRY-PEROT METHOD FOR THE CHARACTERIZATION OF INTEGRATED OPTICAL DIRECTIONAL-COUPLERS

A method to measure the loss and the power-transfer ratio of direction al couplers is presented. It is based on the Fabry-Perot resonances fr om end-facet reflections. The dependence of the accuracy of the measur ements on the facet tilts is described. For low facet misalignments, a n uncertainty <0.3 dB in the loss measurements and power-transfer-rati o measurement errors <1% are obtained. For arbitrary facet tilts the e rrors depend on the extinction ratios. Experimental measurements are r eported to verify the method, and its application to multimode interfe rence couplers is shown. (C) 1995 Optical Society of America