Title :
Phase-shifted Bragg-grating filters with improved transmission characteristics
Author :
Zengerle, Remigius ; Leminger, Ottokar
Author_Institution :
Deutsche Telekom, Forschungs und Technologiezentru, Darmstadt, Germany
fDate :
12/1/1995 12:00:00 AM
Abstract :
Standard Bragg filters (dielectric waveguides with a grating overlay) show a stopband only in reflection. Filters with quarter-wave-shifted gratings have an extremely narrow transmission peak the center of the stopband but its shape (a sharp triangle with a broad bottom) is not suitable for system design. Using standard coupled-mode theory together with transfer-matrix formalism, we show that by introducing several phase-shift regions and properly choosing their locations and magnitudes the transmission spectrum can be tailored into a nearly rectangular shape. For InP-InGaAsP based Bragg-grating filters estimates are made of achievable channel spacings in wavelength-division multiplexing systems
Keywords :
III-V semiconductors; diffraction gratings; gallium arsenide; gallium compounds; indium compounds; integrated optics; matrix algebra; optical communication equipment; optical design techniques; optical waveguide filters; optical waveguide theory; wavelength division multiplexing; In/InGaAsP-based Bragg-grating filters; InP-InGaAsP; achievable channel spacings; dielectric waveguides; extremely narrow transmission peak; grating overlay; improved transmission characteristics; phase-shifted Bragg-grating filters; quarter-wave-shifted gratings; rectangular shape; reflection; several phase-shift regions; standard coupled-mode theory; stopband; transfer-matrix formalism; transmission spectrum; wavelength-division multiplexing systems; Band pass filters; Bandwidth; Bragg gratings; Channel spacing; Couplings; Dielectrics; Filters; Frequency; Optical films; Optical filters; Passband; Reflection; Refractive index; Resonator filters; Shape; Wavelength division multiplexing;
Journal_Title :
Lightwave Technology, Journal of
