While there have been several attempts recently to extend the accuracy of vector coupled-mode theory beyond the usual first-order expression for evanescent couplers, as yet no analytical method is available for describing the polarization properties of couplers with a large core-cladding index jump. Here we present a quasi-static approximation for couplers of low V value, where V is the usual waveguide parameter.
© 1988 Optical Society of America
A. Ankiewicz, A. Altintas, and A. W. Snyder, "Polarization properties of evanescent couplers," Opt. Lett. 13, 524-526 (1988)