Title :
Design considerations for vertical δk directional coupler
Author_Institution :
Dept. of Electr. Eng., California Univ., San Diego, CA, USA
fDate :
8/1/1993 12:00:00 AM
Abstract :
Theoretical results relevant to the design of a vertical Δκ switch are presented. The principle of a Δκ switch is the modulation of the coupling length by the application of an even electrooptic perturbation on the coupling region. Power switching requires that ΔκL=π/2. The initial state can be tuned electrically. The coupling length and the change with the index perturbation depend on many factors, such as the thickness and the refractive index of the coupling layer. Based on an analytic solution of the eigenmodes and eigenindices of the symmetric structure, the author clarifies many of these dependencies and obtains the relationship between the switching length required for power crossover and the available index change. The merits of the Δκ switch are discussed, and its efficiency is compared with that of the conventional Δβ switch
Keywords :
directional couplers; eigenvalues and eigenfunctions; electro-optical devices; optical couplers; optical design techniques; optical modulation; optical switches; optical waveguide theory; perturbation theory; refractive index; analytic solution; coupling layer; coupling length; coupling region; eigenindices; eigenmodes; even electrooptic perturbation; index change; index perturbation; initial state; layer thickness; optical coupler design; optical modulation; power crossover; power switching; refractive index; switching length; symmetric structure; tuned electrically; vertical δk directional coupler; Directional couplers; Electrooptic modulators; Optical refraction; Optical switches; Optical variables control; Optical waveguides; Refractive index; Semiconductor materials; Semiconductor waveguides; Voltage;
Journal_Title :
Lightwave Technology, Journal of
