Title :
Effect of Modulator Bias Control in the Presence of a Finite Extinction Ratio in DQPSK Pre-Equalization Systems
Author :
Sugihara, Takashi ; Yoshida, Tsuyoshi ; Ishida, Kazuyuki
Author_Institution :
Mitsubishi Electr. Corp., Kamakura, Japan
fDate :
3/1/2012 12:00:00 AM
Abstract :
The effect of the finite extinction ratio of a dual-parallel Mach-Zehnder modulator in 43-Gb/s differential quadrature phase-shift keying systems employing pre-equalization is reported. The degradation of the signal quality with 10000-ps/nm dispersion pre-equalization is 2.9 dB at an extinction ratio of 26 dB. We show that bias adjustment can improve the degradation due to a finite extinction ratio. The improvement at an extinction ratio of 26 dB is 2.2 dB. In practical pre-equalized systems, bias control is a key enabler for maintaining high signal quality.
Keywords :
differential phase shift keying; modulation; quadrature phase shift keying; signal processing; DQPSK preequalization system; bias adjustment; differential quadrature phase-shift keying; dispersion preequalization; dual-parallel Mach-Zehnder modulator; finite extinction ratio; modulator bias control; signal quality degradation; Electric fields; Extinction ratio; Optical fibers; Optical modulation; Optical transmitters; Optical communication; optical fiber dispersion; optical modulation; optical transmitters; signal processing;
Journal_Title :
Photonics Technology Letters, IEEE
DOI :
10.1109/LPT.2011.2179794
