DocumentCode :
793187
Title :
Loss-imbalance equalization in arrayed waveguide-grating (AWG) multiplexer cascades
Author :
Ishida, Osamu ; Takahash, Hiroshi
Author_Institution :
NTT Opt. Network Syst. Labs., Kanagawa, Japan
Volume :
13
Issue :
6
fYear :
1995
fDate :
6/1/1995 12:00:00 AM
Firstpage :
1155
Lastpage :
1163
Abstract :
How to connect arrayed-waveguide-grating (AWG) multiplexers in cascade is discussed with the goal of equalizing the loss imbalance among frequency-division-multiplexed (FDM) channels. This paper proposes to average the FDM-channel loss over the cascaded multiplexers by shifting port connections between each adjacent multiplexer. A simulation predicts that, in a cascade of M periodic N×N multiplexers, shifting the connections by N/M reduces the loss imbalance from MΔα to Δα/M where Δα [dB] denotes the loss imbalance per multiplexer. This improvement will extend the cascadable node number in all-optical FDM networks. The prediction is confirmed experimentally in an optical add-drop filter (M=2) constructed with a silica-based AWG 16×16 multiplexer; the largest loss difference among 15 FDM channels is reduced from 5.0 dB to 1.5 dB. This paper also reports that imperfect multiplexer periodicity due to waveguide dispersion restricts the equalizable frequency bandwidth to less than several free spectral ranges (FSR´s)
Keywords :
diffraction gratings; frequency division multiplexing; multiplexing equipment; optical communication equipment; optical dispersion; optical fibre filters; optical fibre losses; optical waveguides; 5 to 15 dB; FDM channels; FDM-channel loss; N×N multiplexers; all-optical FDM networks; arrayed waveguide-grating multiplexer cascades; cascadable node number; cascaded multiplexers; equalizable frequency bandwidth; free spectral ranges; frequency-division-multiplexed; loss difference; loss imbalance; loss-imbalance equalization; multiplexer; multiplexer periodicity; optical add-drop filter; port connections; silica-based AWG; simulation; waveguide dispersion; Add-drop multiplexers; Arrayed waveguide gratings; Frequency division multiplexing; Optical add-drop multiplexers; Optical diffraction; Optical fiber networks; Optical filters; Optical losses; Optical waveguides; Phased arrays;
fLanguage :
English
Journal_Title :
Lightwave Technology, Journal of
Publisher :
ieee
ISSN :
0733-8724
Type :
jour
DOI :
10.1109/50.390233
Filename :
390233
Link To Document :
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