MODELING AND ANALYSIS OF FIBEROPTIC MODE TRANSDUCERS - SINGLE FIBER WITH PERIODIC PERTURBATIONS

The fiber-optic LP01 if and only if LP11 mode transducers are analyzed by a scalar coupled-mode theory with vector correction. This paper deals with the fiber-optic mode transducers made of a single fiber with periodic perturbations due to microbends, acoustic waves, or photoinduced index grating. Both the couplings caused by the index perturbations and by the vector property of the fields (polarization effect) are taken into account in the analysis. Approximate analytical solutions to the coupled-mode equations are obtained. The power exchange among the modes along the fiber and spectral properties of the mode transducers are examined. The functions of the mode transducers used as wavelength filters and polarizers are studied.