Title :
Coupled-mode analysis of highly asymmetric directional couplers with periodic perturbation
Author :
Borges, B.-H.V. ; Herczfeld, P.R.
Author_Institution :
Sao Paulo Univ., Brazil
fDate :
3/1/1998 12:00:00 AM
Abstract :
This paper presents an in-depth analysis of highly asymmetric grating assisted directional couplers. The directional coupler consists of a polymer waveguide with dimensions and refractive indices closely matching a single-mode fiber fabricated atop a Ga0.6Al0.4As/GaAs/Ga0.4Al0.6 As waveguide. The structure is investigated analytically by means of a new orthogonal coupled-mode theory formulated in terms of the Lorentz reciprocity theorem. For the first time, the analysis includes three distinct loss mechanisms, namely, the leakage of power toward the semiconductor substrate, the power lost to radiation modes (mode mismatching), and the grating radiation loss
Keywords :
Lorentz transformation; coupled mode analysis; directional couplers; optical fibre couplers; optical fibre losses; refractive index; Ga0.6Al0.4As-GaAs-Ga0.4Al 0.6As; Lorentz reciprocity theorem; asymmetric directional couplers; coupled-mode analysis; grating assisted directional couplers; grating radiation loss; loss mechanisms; mode mismatching; orthogonal coupled-mode theory; periodic perturbation; polymer waveguide; radiation modes; refractive indices; single-mode fiber; Coupled mode analysis; Directional couplers; Gratings; Optical fiber couplers; Optical fibers; Optical waveguides; Polymers; Rectangular waveguides; Semiconductor waveguides; Substrates;
Journal_Title :
Microwave Theory and Techniques, IEEE Transactions on
