ON THE ZERO BENDING-INDUCED PHASE-SHIFT IN A DUAL-MODE RECTANGULAR ELLIPTICAL CORE WAVE-GUIDE/

Using the recently developed analysis for an arbitrarily bent dual-mod e rectangular core waveguide (RCW), we investigate here the conditions under which the bending induced phase shift in such waveguides is zer o. It is found that waveguides with sufficiently large V-values when b ent in a certain plane (at an angle theta(0) with respect to the major axis) exhibit no bending-induced phase shift. The variation in the va lue of theta(0) and the variation in the phase shift around theta(0) w ith various waveguide parameters are studied in detail. The study shou ld be useful in designing bending-insensitive dual mode e-core fiber s ensors. (C) 1997 Elsevier Science B.V.