The Experts below are selected from a list of 8595 Experts worldwide ranked by ideXlab platform
Jianjun Yu - One of the best experts on this subject based on the ideXlab platform.
-
Phase Factor Optimization for QPSK Signals Generated from MZM Based on Optical Carrier Suppression
IEEE Photonics Journal, 2017Co-Authors: Jianjun Yu, Long ChenAbstract:We propose and experimentally demonstrate one novel scheme to improve the performance of the vector millimeter-wave (mm-wave) signal generated by intensity modulator based on Optical Carrier suppression. The phase distribution of the vector mm-wave signal after one square-law photodiode detection becomes nonuniform. We optimize the phase factor at the transmitter side and make the phase distribution of the quadrature phase-shift keying signal to be symmetrical at the receiver.
-
Wavelength Conversion Based on Copolarized Pumps Generated by Optical Carrier Suppression
IEEE Photonics Technology Letters, 2009Co-Authors: Jianjun Yu, Ming-fang HuangAbstract:Polarization-insensitive wavelength conversion based on four-wave mixing for 112-Gb/s polarization- multiplexed return-to-zero quadrature phase-shift keying signals (PolMux-RZ-QPSK) with digital coherent detection is experimentally demonstrated. The dual-pumps always have the same polarization direction and fixed frequency spacing because they are generated by the Optical Carrier suppression technique. The conversion efficiency at different pumping powers and signal wavelengths has also been investigated. A tuning range of a signal wavelength of wider than 18 nm is realized with the same conversion efficiency in this proposed architecture. There is no obvious Optical signal-to-noise ratio penalty for the converted 112-Gb/s PolMux-RZ-QPSK signals.
-
DSB Optical mm-wave with signal only on Optical Carrier generated by embedded LiNbO3 Mach–Zehnder modulator
Optics Communications, 2008Co-Authors: Jianxin Ma, Jianjun Yu, Lin Chen, Chongxiu Yu, Kuiru WangAbstract:We have investigated the generation of the 40-GHz double-sideband Optical millimeter (mm)-wave with signal carried only by its Optical Carrier via an embedded LiNbO3 Mach–Zehnder modulator (LN-MZM). Since the Optical Carrier and its two first-order sidebands are dominant and their powers are well balanced, the first-order harmonic in the photocurrent gets maximal. As the Optical mm-wave signal is transmitted along the fiber, there is no code outline distortion because the signal is only modulated on the Optical Carrier. Although the first-order harmonic shows the periodical fading effect when the Optical mm-wave signal is transmitted along the fiber, its degradation on the radio-over-fiber link can be avoided by adjusting the position of the fading nodes via varying the main MZM bias voltage, and the signal still keeps much good eye diagram even after 50-km fiber transmission. The experimental results prove our theory.
-
frequency upconversion of multiple rf signals using Optical Carrier suppression for radio over fiber downlinks
Optics Express, 2007Co-Authors: Zhenbo Xu, Xiupu Zhang, Jianjun YuAbstract:We propose and analyze a technique of an Optical Carrier transmitting two RF signals using Optical Carrier suppression. A single Optical Mach-Zehnder modulator is used for both Optical Carrier suppression and signal modulation, and Optical Carrier suppression modulation is also used for frequency conversion of RF signals. This work shows that in contrary to the case of an Optical Carrier transmitting a single RF signal with Optical Carrier suppression where stronger Optical Carrier suppression improves the upconverted RF signal, weaker Optical Carrier suppression is preferred for an Optical Carrier transmitting two RF signals due to nonlinear distortion because the nonlinear distortion is reduced by using weaker Optical Carrier suppression. We find that the usable range of Optical Carrier suppression ratio is from 10 to 18 dB for RF signal upconverted to 20 GHz and beyond, and the best Optical Carrier suppression ratio is around 10 dB. We verify the concept and analysis with experiment. In experiment, we used two RFs at 6 and 18 GHz transmitting two 750 Mb/s signals. The experiment for the first time demonstrated that an Optical Carrier can transmit two RF signals using Optical Carrier suppression and showed that upconverted RF signals are degraded by nonlinear distortion, particularly for upconverted RF signal at 12 GHz, i.e. the RF signal at the lower frequency.
-
Milimeter-Wave Optical SubCarrier Generation by Using an External Modulator and Optical Carrier Suppression
2007 9th International Conference on Transparent Optical Networks, 2007Co-Authors: Chongxiu Yu, Jianjun Yu, Xinzhu Sang, Qi Zhang, Junying ZengAbstract:In this paper, we have theoretically investigated the transmission performance of the Optical millimeter (mm)- wave generated by using an external modulator based on Optical Carrier suppression for the first time. According to our theory, the data signals carried by the Optical mm-wave are transmitted in the dispersion fiber without fading but are degraded greatly because of the time shift of the code edges, which still limits the transmission distance. The experimental results agree well with our theory.
Gee-kung Chang - One of the best experts on this subject based on the ideXlab platform.
-
Heterodyne Optical Carrier Suppression for Millimeter-Wave-over-Fiber Systems
Journal of Lightwave Technology, 2013Co-Authors: Gee-kung ChangAbstract:Optical Carrier suppression (OCS) has been considered one of the most promising modulation schemes used in radio-over-fiber femto-cell systems to generate millimeter-wave (mmwave) in V-band (60 GHz) or E-band (71 to 93 GHz) for its low bandwidth requirement, simplicity, robustness, and Optical-to-radio conversion efficiency. A novel mmwave generation scheme based on a superheterodyne OCS structure is introduced to overcome the limitations of the conventional homodyne OCS scheme, including vector-signaling, uplink Optical-millimeter conversion, and inter-radio-frequency band interferences. The transmission performance and characteristics of conventional and newly-introduced mmwave generation schemes are investigated thoroughly in this research to fulfill the requirements of various applications.
-
Full-duplex 60 GHz vector-signal radio-over-fiber system using heterodyne Optical-Carrier suppression
OFC NFOEC, 2012Co-Authors: Yu-ting Hsueh, Ting Wang, Gee-kung ChangAbstract:To overcome the fundamental limitation of conventional Optical-Carrier-suppression, we proposed a novel heterodyne Optical-Carrier-suppression to achieve centralized up/down-conversion in the radio-over-fiber system. Full-duplex 60-GHz BPSK transmission has been achieved after 25-km single-mode fibers.
-
Novel 100Gbps Ethernet Systems for Next-generation Metro Transport and Wide-area Access Networks using Optical Carrier suppression and separation Technique
2007 Digest of the IEEE LEOS Summer Topical Meetings, 2007Co-Authors: Arshad Chowdhury, Gee-kung Chang, Richard YounceAbstract:A novel, dispersion tolerant, spectrally efficient scheme of transmitting 100 Gbps per wavelength channel by exploiting Optical Carrier suppression and separation technique and Optical duobinary or DQPSK modulation is proposed and evaluated through numerical simulation.
-
A full-duplex radio-over-fiber system based on Optical Carrier suppression and reuse
IEEE Photonics Technology Letters, 2006Co-Authors: Jianjun Yu, Gee-kung ChangAbstract:We have experimentally demonstrated a full-duplex radio-over-fiber system using a single light source at central station (CS). Optical Carrier suppression modulation scheme was employed to generate 40-GHz Optical millimeter wave and up-convert the baseband signal simultaneously at CS for downlink transmission while the same Optical Carrier was reused at base station for uplink connection. The bidirectional full-duplex 2.5-Gb/s data was successfully transmitted over 40-km standard single-mode fiber (SMF-28) for both upstream and downstream channels with less than 2-dB power penalty. This system shows simple cost-efficient configuration and good performance over long-distance delivery
-
Transmission performance of the Optical mm-wave signals generated by Optical Carrier suppression
LEOS 2006 - 19th Annual Meeting of the IEEE Lasers and Electro-Optics Society, 2006Co-Authors: Chongxiu Yu, Jianjun Yu, Gee-kung Chang, Xinzhu SangAbstract:We theoretically investigated the transmission performance of Optical mm-wave signals generated by Optical Carrier suppression (OCS). Our results show that the signals carried by OCS Optical millimeter-wave is not suffered from fading effect, but it will be degraded by the code-edges' time shift, hence the maximum transmission distance is limited
Ningbo Huang - One of the best experts on this subject based on the ideXlab platform.
-
Widely Tunable Single-Passband Microwave Photonic Filter Based on DFB-SOA-Assisted Optical Carrier Recovery
IEEE Photonics Journal, 2015Co-Authors: Ye Deng, Ming Li, Jian Tang, Ningbo HuangAbstract:A widely tunable single-passband microwave photonic filter (MPF) based on a distributed-feedback semiconductor Optical amplifier (DFB-SOA) is proposed and experimentally demonstrated in this paper. The fundamental principle is to recover the suppressed Optical Carrier from a passband Optical filter by the wavelength-selective amplification via a DFB-SOA. A microwave signal is then generated by beating the recovered Optical Carrier with the phase-modulated lower sideband, and thus, an MPF is achieved with the shape of the passband Optical filter that is mapped from the Optical domain to the electrical domain. By tuning the central wavelength of the passband Optical filter, a single-passband MPF with a frequency tuning range from 5 to 35 GHz is obtained. The 3-dB bandwidth and the out-of-band suppression ratio are measured to be 4 GHz and 20 dB, respectively. In addition, the tunability of the MPF that is dependent on the driven current of the DFB-SOA is also experimentally investigated.
Chun-kit Chan - One of the best experts on this subject based on the ideXlab platform.
-
A Centrally Controlled Survivable WDM-PON Based on Optical Carrier Suppression Technique
IEEE Photonics Technology Letters, 2011Co-Authors: Chun-kit ChanAbstract:A simple centrally controlled survivable wavelength-division-multiplexed passive Optical network (WDM-PON) architecture employing an Optical Carrier suppression technique is proposed. Protection switching at the Optical line terminal employs electrical switches to control the clock signal for the protection subCarrier generation, via Optical Carrier suppression. Both distribution and feeder fibers are protected simultaneously. By employing an inverse-return-to-zero format for the downstream transmission and nonreturn-to-zero for the upstream remodulated signal, the Optical network units are kept colorless and simple. The 10-Gb/s transmissions under both normal working and protection modes were experimentally demonstrated and traffic restoration time was measured to be about 5 ms.
-
A novel multicast overlay scheme for WDM passive Optical networks using Optical Carrier suppression technique
2009 35th European Conference on Optical Communication, 2009Co-Authors: Chun-kit ChanAbstract:A WDM-PON with simultaneous delivery of 10-Gb/s downstream unicast and upstream data as well as 10-Gb/s multicast data is proposed. Downstream multicast data is superimposed onto the subCarrier generated by Optical Carrier suppression technique.
Ye Deng - One of the best experts on this subject based on the ideXlab platform.
-
Tunable single passband microwave photonic filter based on DFB-SOA-assisted Optical Carrier recovery
2015 14th International Conference on Optical Communications and Networks (ICOCN), 2015Co-Authors: Ye Deng, Ming Li, Jian TangAbstract:A tunable single passband microwave photonic filter (MPF) based on a distributed-feedback semiconductor Optical amplifier (DFB-SOA) is proposed and experimentally demonstrated in this paper. The fundamental principle is to recover the suppressed Optical Carrier from a passband Optical filter by the wavelength-selective amplification of the DFB-SOA. A microwave signal is then generated by beating the recovered Optical Carrier with the phase modulated lower sideband and thus a MPF is achieved with the shape of the passband Optical filter which is mapped from Optical domain to electrical domain. By tuning the central wavelength of the passband Optical filter, a single passband MPF with frequency tuning range from 5 to 35 GHz is obtained. The 3-dB bandwidth and the out-of-band suppression ratio are measured to be 4 GHz and 20 dB, respectively.
-
Widely Tunable Single-Passband Microwave Photonic Filter Based on DFB-SOA-Assisted Optical Carrier Recovery
IEEE Photonics Journal, 2015Co-Authors: Ye Deng, Ming Li, Jian Tang, Ningbo HuangAbstract:A widely tunable single-passband microwave photonic filter (MPF) based on a distributed-feedback semiconductor Optical amplifier (DFB-SOA) is proposed and experimentally demonstrated in this paper. The fundamental principle is to recover the suppressed Optical Carrier from a passband Optical filter by the wavelength-selective amplification via a DFB-SOA. A microwave signal is then generated by beating the recovered Optical Carrier with the phase-modulated lower sideband, and thus, an MPF is achieved with the shape of the passband Optical filter that is mapped from the Optical domain to the electrical domain. By tuning the central wavelength of the passband Optical filter, a single-passband MPF with a frequency tuning range from 5 to 35 GHz is obtained. The 3-dB bandwidth and the out-of-band suppression ratio are measured to be 4 GHz and 20 dB, respectively. In addition, the tunability of the MPF that is dependent on the driven current of the DFB-SOA is also experimentally investigated.
