Abstract

The filter characteristics of smoothly weighting or tapering the coupling between codirectional interacting waveguides and contradirectional Bragg reflection devices have been studied and reported. Filters of both types have promise for use in integrated optical waveguide circuits for light-wave communications. Specific applications that have been identified are wavelength multiplexers or demultiplexers, polarization-independent optical switches or modulators, and Bragg mirrors. The interaction between the two modes in either device is described by a nonlinear Ricatli equation.¹ In general, the local coupling between the modes is described by a coupling coefficient κ(Z). Several functional relations for κ(Z) have been studied for their filter characteristics. The ones producing the lowest sidelobe levels to date have been a set of "window" functions that have been thoroughly studied for their properties as digital filters: In this paper we consider a truncated Gaussian to describe the functional behavior of κ(z).

© 1982 Optical Society of America