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Compact Opto-Electronic Wavelength Selector with Large Channel Capacity

IP.com Disclosure Number: IPCOM000116381D
Original Publication Date: 1995-Sep-01
Included in the Prior Art Database: 2005-Mar-30
Document File: 2 page(s) / 43K

Publishing Venue

IBM

Related People

Kwark, YH: AUTHOR [+5]

Abstract

Wavelength Division MultiAccess networks (WDMA) require compact, low-cost tunable filters/receivers capable of covering a wide spectral range but with a narrow bandwidth. In a packet-switched data communication environment, the tunable receivers are further required to support large number of channels, and the wavelength channels have to be re-configured in a relatively short interval (with respect to the packet length).

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Compact Opto-Electronic Wavelength Selector with Large Channel Capacity

      Wavelength Division MultiAccess networks (WDMA) require
compact, low-cost tunable filters/receivers capable of covering a
wide spectral range but with a narrow bandwidth.  In a
packet-switched data communication environment, the tunable receivers
are further required to support large number of channels, and the
wavelength channels have to be re-configured in a relatively short
interval (with respect to the packet length).

      Disclosed is a multiple-channel tunable receiver with a channel
separation of &tilde.1 nm and a tuning time of &tilde.10 ns.  The
receiver is tuned digitally.  The structure consists of a SiO sub 2 /
Si planar waveguide grating demultiplexer which spatially resolves
the input optical signals of multiple wavelengths (from the input
fiber) into different output waveguides.  The resolved optical
channels are coupled to large area InGaAs MSM photo-detectors via a
reflection by a 45º mirror (formed by polishing the end face of
the grating) and focused by a lens array.  There is a spacer of
&tilde.500 mm between the lens array and the ceramic package to
provide clearance of the capillary guiding tube holding the input
fiber.  The photo-detectors are connected to transimpedance
amplifiers integrated with electronic switches.  The channel
selection is based on sequential switching of the received optical
signals in stages at the analog level.  There are four
photo...