Title :
Analysis of wavelength-selective photodetectors based on grating-assisted forward coupling
Author_Institution :
Canon Res. Center, Kanagawa, Japan
fDate :
4/1/1993 12:00:00 AM
Abstract :
Grating-assisted vertical directional couplers can be combined with evanescently coupled absorption layers to realize integrated wavelength-selective photodetectors. The multimode structure of a photodetector including layered waveguides is studied, and mode transfer from the lossless filter section to the absorptive detector section is analyzed. By optimizing the device structure, the background absorption of unselected wavelengths can be suppressed, and, as a result, high crosstalk attenuation can be obtained. The filter bandwidth can be designed to cover a wide range from on the order of 10 nm down to the order of 0.5 nm with a device length that is shorter than 2 mm, which makes it suitable for various types of wavelength-division-multiplexing systems
Keywords :
crosstalk; diffraction gratings; directional couplers; optical communication equipment; optical couplers; optical filters; optical losses; optical waveguide theory; photodetectors; wavelength division multiplexing; 2 mm; WDM optical communications equipment; absorptive detector section; background absorption; device length; device structure; evanescently coupled absorption layers; filter bandwidth; grating-assisted forward coupling; high crosstalk attenuation; layered waveguides; lossless filter section; mode transfer; multimode structure; unselected wavelengths; vertical directional couplers; wavelength-division-multiplexing systems; wavelength-selective photodetectors; Absorption; Detectors; Directional couplers; Gratings; Optical coupling; Optical filters; Optical receivers; Optical waveguides; Photodetectors; Wavelength division multiplexing;
Journal_Title :
Lightwave Technology, Journal of
