DocumentCode :
1766454
Title :
Optimum Bias Point in Broadband Subcarrier Multiplexing With Optical IQ Modulators
Author :
Gutierrez, Fernando A. ; Perry, Philip ; Smyth, Frank ; Ellis, A.D. ; Barry, Liam P.
Author_Institution :
RINCE Inst., Dublin City Univ., Dublin, Ireland
Volume :
33
Issue :
1
fYear :
2015
fDate :
Jan.1, 1 2015
Firstpage :
258
Lastpage :
266
Abstract :
This paper develops a theoretical analysis of the tradeoff between carrier suppression and nonlinearities induced by optical IQ modulators in direct-detection subcarrier multiplexing systems. The tradeoff is obtained by examining the influence of the bias conditions of the modulator on the transmitted single side band signal. The frequency components in the electric field and the associated photocurrent at the output of the IQ modulator are derived mathematically. For any frequency plan, the optimum bias point can be identified by calculating the sensitivity gain for every subchannel. A setup composed of subcarriers located at multiples of the data rate ensures that the effects of intermodulation distortion are studied in the most suitable conditions. Experimental tests with up to five QPSK electrical subchannels are performed to verify the mathematical model and validate the predicted gains in sensitivity.
Keywords :
broadband networks; intermodulation distortion; modulators; quadrature phase shift keying; subcarrier multiplexing; QPSK electrical subchannels; broadband subcarrier multiplexing; carrier suppression; data rate; direct-detection subcarrier multiplexing systems; electric field; frequency components; intermodulation distortion; mathematical model; nonlinearities; optical IQ modulators; optical subcarrier multiplexing; optimum bias point; sensitivity gain; transmitted single side band signal; Amplitude modulation; Nonlinear optics; Optical distortion; Optical modulation; Optical sensors; Sensitivity; Carrier to signal power ratio (CSPR); nonlinear distortion (NLD); optical IQ modulator; subcarrier multiplexing (SCM);
fLanguage :
English
Journal_Title :
Lightwave Technology, Journal of
Publisher :
ieee
ISSN :
0733-8724
Type :
jour
DOI :
10.1109/JLT.2014.2384838
Filename :
6994254
Link To Document :
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