Browsing by Author "Wei, Chia Chien"

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A 40-Gb/s OFDM PON System Based on 10-GHz EAM and 10-GHz Direct-Detection PIN
(2012-01-01)
Chen, Hsing-Yu
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Wei, Chia Chien
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Hsu, Dar-Zu
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Yuang, Maria C.
;
Chen, Jyehong
This letter demonstrates a 40-Gb/s optical double-sideband (ODSB) orthogonal frequency-division multiplexing passive optical network (OFDM-PON) system using a cost-effective 10-GHz-bandwidth electroabsorption modulator (EAM). By employing a subcarrier-adaptive modulation format and pre-emphasis, we successfully achieve 20-km EAM-based single-mode-fiber (SMF) transmission.
Convergence of phase fluctuation induced by intrachannel four-wave mixing in differential phase-shift keying transmission systems via phase fluctuation averaging
(2007-05-15)
Wei, Chia Chien
;
Chen, Jason (Jyehong)
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光電工程學系
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Department of Photonics
This work investigates the effect of phase fluctuation averaging on phase fluctuation induced by intrachannel four-wave mixing (IFWM) in highly dispersed differential phase-shift keying transmission systems. Through repeatedly averaging the phase fluctuations of adjacent pulses, a simple analytical model and numerical simulation revealed that the IFWM-induced differential phase fluctuation is suppressed and convergent, even after an ultralong transmission. The influence of averaging the phase fluctuations on the bit error rate is also evaluated by the semianalytical method. (c) 2007 Optical Society of America.
Convergence of phase noise in DPSK transmission systems by novel phase noise averagers
(2006-10-16)
Wei, Chia Chien
;
Chen, Jason (Jyehong)
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光電工程學系
;
Department of Photonics
This investigation proposes a novel all-optical phase noise averager to reduce residual phase noise in the differential phase-shift keying (DPSK) transmission system with phase-preserving amplitude regenerators. The proposed phase noise averager is based on a phase-sensitive amplifier but does not require an extra phase-locking optical pump beam. It can increase the correlation between the phase noises of neighboring bits and greatly reduce the differential phase noise in the transmission system. Independently of the cascaded spans, analytical analysis demonstrates that, in the DPSK system with repeated averagers, the total differential phase noise will be less than that before the first averager. Theoretical analysis and numerical simulation are carried out and confirm the significant improvement of DPSK signals using the proposed novel phase noise averagers. (c) 2006 Optical Society of America
Effects of filter bandwidth and driving voltage on optical duobinary transmission systems
(2007-07-01)
Lu, Yu Chang
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Wei, Chia Chien
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Chen, Jason (Jyehong)
;
Feng, Kai Ming
;
Yeh, Pao Chi
This work demonstrates how electrical driving voltage of a Mach-Zehnder modulator and the bandwidth of electrical low-pass filters (LPFs) affect optical duobinary signals. The fact that a 100% driving voltage does not necessarily yield optimal results in duobinary systems is established both numerically and experimentally. Various filter bandwidths correspond to respective optimum driving voltages. In a 10 Gbps duobinary system, compared with the conventional condition of using a 2.5 GHz electrical LPF, a 2.5 dB sensitivity improvement is obtained by employing a 3 GHz LPF with an 88% driving voltage of fully driving. (c) 2007 Published by Elsevier Inc.
Study on dispersion-induced phase noise in an optical OFDM radio-over-fiber system at 60-GHz band
(2010-09-27)
Wei, Chia Chien
;
Chen, Jason (Jyehong)
;
光電工程學系
;
Department of Photonics
While coherency between an RF-tone and OFDM signals in RoF systems at 60 GHz is de-correlated by fiber dispersion, both phase rotation term (PRT) on each subcarrier and inter-carrier interference (ICI) between subcarriers are induced at a receiver. We analytically calculate the powers of PRT and ICI under different parameters, such as subcarrier number, modulation format, laser linewidth and transmission distance. Moreover, dispersion-induced ICI is shown to be non-Gaussian distributed by its kurtosis, and its distribution depends on system parameters. Therefore, using only the power of ICI cannot predict accurate bit error rate (BER) and corresponding power penalty. We propose to use t-distribution to fit the distribution of ICI, and it can be used to compute BER precisely. (C) 2010 Optical Society of America