Propagation in curved waveguides and applications

This paper is a review of the various methods described in the literature for propagation in curved waveguides for many applications. Marcatili and Schmeltzer were the first researchers in the field of bent waveguides. Other researchers have included Marhic, Miyagi, Kawakami, Falciai and Harrington. Many other interesting methods have been suggested by the other researchers in the literature as improved solutions to the problems of bending. Some recent authors have presented methods to solve the problems of curved waveguides as well (improved ray model, improved mode model, etc.). This paper is meant to allow researchers to be updated with recent publications in the entire field of propagation in bent waveguides. The methods described may serve for an analysis of curved waveguides in the IR regimes and in the microwave and millimeter wave regimes, with potential applications for medical devices and for using diffused optical waveguides in integrated optics.