Slant-propagation characteristics in tapered optical waveguides: analysis

Abstract

Although several analysis methods for tapered waveguides have been proposed, they dealt with the problem of a light wave traveling parallel to the tapered direction of the waveguide. Light waves that propagate at a slant in the tapered direction are discussed as mode-coupling problems, including radiation modes that are made discrete by the hypothetical boundary method. We propose a method of determining the three-dimensional wave vectors of the discrete radiation modes in the slant propagation; the slant-propagation characteristics, such as the transmission efficiency of the tapered waveguide, are analyzed.

Optical Waveguide Device for a Magneto-Optical Disk Head

“…Therefore high transmission efficiency is essential for the taper region to connect smoothly the bi-prism with the other region. On the assumption that the light beam propagates in a direction inclining to the taper region edge at an angle of 45 degrees, we can maximize the transmission efficiency using the Hypothetical Boundary Method for a slant propagation [4].…”

“…The Ta z 0 5 layer also has a refractive index of2.05 to enable the mode splitting for the divergent beam. In the tapered region, based on the transmission efficiency calculated by the above method [4], the inclination of the Ta z 0 5 layer is determined. As shown in Fig.…”