LP01–LP11Intermodal Interference in Highly Birefringent Two-mode Fibres with Differential LP11Polarization-mode Attenuation

Abstract Starting from the experimental observation and the theoretical prediction that different types of highly birefringent (Hi-Bi) fibres suppress different LP11 polarization modes, a generalized theoretical analysis of LP01–LP11 intermodal interference in Hi-Bi bimodal optical fibres is presented. Differential attenuation for each of the four LP11 polarization modes is assumed and, on this basis, spatial Stokes parameters accounting for intermodal interference effects are derived. The most important particular cases of elliptical-core, bow-tie and PANDA-type fibres are considered. The application to combined polarimetric and polarization sensitive intermodal sensors, as well as to simultaneous multiparameter sensing in Hi-Bi fibres is commented upon.