INTERFEROMETRIC MODEL FOR PHASE-ANALYSIS IN FIBER COUPLERS

An interferometric model is proposed to estimate the phase differences in lossless, strongly coupled biconical fiber couplers. This approxim ate method is simpler than the traditional s-parameter network theory- based analysis technique and minimizes the number of unknowns. The pha se difference between the transmitted and coupled light fields is dire ctly related to the field interaction and can be estimated by employin g the energy conservation and mode orthogonality principles. The maxim um coupling coefficient and dependence of phase difference on coupling conditions can be analyzed for multiport single-mode fiber couplers. (C) 1996 Optical Society of America