Slant-propagation Characteristics in Tapered Optical Waveguides: Analysis

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.