Browsing by Author "Tai, C"

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33-channel 64-QAM signal transmission using a 1.3-mu m semiconductor optical amplifier
(1996-01-01)
Chiang, PY
;
Tai, C
;
Way, WI
;
電信工程研究所
;
電信研究中心
From the network evolution point of view, optical amplifiers in a hybrid fiber coaxial (HFC) system may become extensively deployed at approximately the same time as when analog AM-VSB video signals are all replaced by digital M-QAM or M-VSB signals. This letter demonstrates the feasibility of using a 1.3-mu m semiconductor optical amplifier to transport 33 channels of 64-QAM signals with 30 Mbps/channel. A total system power budget of 20.3 dB was obtained.
Dynamic range and switching speed limitations of an NxN optical packet switch based on low-gain semiconductor optical amplifiers
(1996-04-01)
Tai, C
;
Way, WI
;
交大名義發表
;
光電工程學系
;
National Chiao Tung University
Two important system performance limitations-dynamic range and switching speed-of an integrated packet switch fabric based on low-gain semiconductor optical amplifiers (SOA's) have been examined by using cascaded blocks of an SOA model, which includes transient effect, nonlinear pulse distortion effect, and amplified spontaneous emission (ASE) noise, Low-gain SOA's were used to minimize ASE noise considering that no optical filters can be integrated in an SOA-based switch fabric, The system performance with and without a narrowband optical filter at the receiver were both studied, By assuming fixed wavelength transmitters and no optical filter can be used at the receiving end owing to the unpredictability of arriving packet wavelengths, our simulation results indicate that the dynamic ranges of 4 x 4 and 8 x 8 SOA-based packet switches at 2.5 Gb/s can only be about 3.2 and 0.8 dB, respectively, However, at 155 Mb/s, even without a receiving-end optical filter, the dynamic range of each switch size can be increased by more than 17 dB as compared to the cases of 2.5 Gb/s, Note that the dynamic ranges were estimated under the conditions of a bit error rate (BER) less than or equal to 10(-9) and a pulse distortion ratio less than or equal to 30%. We have also shown that, when an optical filter with a 1 nm bandwidth was used at the receiving end to simulate 1) a circuit-switched condition where the center wavelength of the filter can be adjusted according to the established circuit, or 2) a packet-switched condition where each receiver has a wavelength demultiplexer and a detector array, the dynamic range of 4 x 4 and 8 x 8 switches can be increased to 16.3 and 14 dB, respectively, at 2.5 Gb/s.
Eight-way, 70-km transmission of 33-channel 64-QAM signals utilizing a 1.3-mu m external modulation system and semiconductor optical amplifier
(1996-09-01)
Tai, C
;
Chiang, PY
;
Way, WI
;
電信工程研究所
;
電信研究中心
By using a 1.3-mu m external modulation system and a semiconductor optical amplifier, we experimentally demonstrated the feasibility of broadcasting 33 channels of 64-QAM digital CATV signals to eight 70-km optical fiber links, The presented results show that, with the vast momentum on developing M-QAM modems, potentially low-cost semiconductor optical amplifiers can possibly expedite the penetration pace of optical fibers in broad-band access networks.
Eight-way, 70-km transmission of 33-channel 64-QAM signals utilizing a 1.3-mu m external modulation system and semiconductor optical amplifier
(1996-09-01)
Tai, C
;
Chiang, PY
;
Way, WI
;
電信工程研究所
;
光電工程學系
By using a 1.3-mu m external modulation system and a semiconductor optical amplifier, we experimentally demonstrated the feasibility of broadcasting 33 channels of 64-QAM digital CATV signals to eight 70-km optical fiber links, The presented results show that, with the vast momentum on developing M-QAM modems, potentially low-cost semiconductor optical amplifiers can possibly expedite the penetration pace of optical fibers in broad-band access networks.
Novel electro-optical pre-distortion technique and its application in externally modulated CATV transmission systems
(1998)
Tsai, KT
;
Tai, C
;
Way, WI
;
電信工程研究所
;
Institute of Communications Engineering
Conventional linearization techniques such as electrical pre-distortion or optical feedforward methods have been applied to Mach-Zehnder interferometer (MZI) modulators for CATV transmission systems. However, both methods can only ensure that the output of the MZI modulator meet the standard CATV requirements on composite second-order (CSO) and composite triple beat (CTB), but cannot guarantee a satisfactory end-to-end system linearity. In this paper, we propose and demonstrate a novel linearization technique, which can simultaneously suppress the nonlinear distortions (NLDs) generated in a transmission system and increase the received carrier-to-noise ratio (CNR). This technique is based on offsetting the MZI bias voltage from its inflection point. Both analytical and experimental results are presented.
Reduction of nonlinear distortion in MQW semiconductor optical amplifier using light injection and its application in multichannel M-QAM signal transmission systems
(1998-04-01)
Tai, C
;
Tzeng, SL
;
Chang, HC
;
Way, WI
;
光電工程學系
By using an external light-injected multiple-quantum-well (MQW) semiconductor optical amplifier (SOA), we have demonstrated a 100-km optical fiber link that transports 77 channels of 63-QAM signals. This is equivalent to a system capacity of 2.3 Gb/s, while using a laser bandwidth of only 550 MHz. Under a requirement of carrier to noise and nonlinear distortion ratio of 30 dB per channel, the 1310-nm gain-peaked SOA input dynamic range was increased from 0 to 9 dB due to an injected light with 8.8 dBm and a wavelength of 1283 nm.