We propose and demonstrate a powerful approach to spectral bandpass engineering (apodization) of one-dimensional channel-waveguide Bragg reflectors. Bandpass engineering is accomplished by precise photolithographic control of the length and the longitudinal placement of individual grating lines, which provides unique line-by-line diffractive amplitude and phase control. Channel-waveguide gratings that exhibit complex filtering functions have been fabricated and modeled. When a second-order apodization effect that comprises effective waveguide refractive-index variation with grating-line length is included in the simulation, extraordinary agreement between predicted and observed spectral passband profiles is obtained.
© 2004 Optical Society of America
(050.1950) Diffraction and gratings : Diffraction gratings
(050.7330) Diffraction and gratings : Volume gratings
(060.2310) Fiber optics and optical communications : Fiber optics
(130.3120) Integrated optics : Integrated optics devices
Christoph Greiner, Thomas W. Mossberg, and Dmitri Iazikov, "Bandpass engineering of lithographically scribed channel-waveguide Bragg gratings," Opt. Lett. 29, 806-808 (2004)