The Experts below are selected from a list of 2055 Experts worldwide ranked by ideXlab platform

Ninghua Zhu - One of the best experts on this subject based on the ideXlab platform.

  • microwave photonic bandstop Filter with wide tunability and adjustable bandwidth
    Optics Express, 2015
    Co-Authors: Chengwu Yang, Jianguo Liu, Ling Wang, Zhilin Yuan, Ninghua Zhu
    Abstract:

    A microwave photonic bandstop Filter is proposed and experimentally demonstrated in this work. The Filter exhibits promising performance combination of reconfigurability, frequency tunability, and bandwidth adjustment. The phase modulation on two orthogonal polarization states produces a Bandpass and a lowpass MPF, respectively. The key concept of destructive interference between the Bandpass and lowpass MPF enables the reconfiguration of MPF from Bandpass to bandstop. By adjusting the wavelength of two orthogonally polarized Optical carriers and the bandwidth of an Optical Bandpass Filter, the bandstop Filter is tunable in terms of center frequency and bandwidth.

  • Optically controlled microwave phase shifter based on nonlinear polarization rotation in a highly nonlinear fiber
    Optics Letters, 2014
    Co-Authors: Wen Hui Sun, Wenting Wang, Ninghua Zhu
    Abstract:

    This Letter reports an Optically controlled microwave phase shifter with an ultra-wideband working bandwidth and a full 360° phase shifting range based on nonlinear polarization rotation (NPR) in a highly nonlinear fiber (HNLF). A continuous wave probe light is modulated by a polarization modulator (PolM) that is driven by a microwave signal to be phase shifted. The Optical carrier and the first-order sidebands of the probe light experience different phase shifts due to the NPR induced by the control light in the HNLF. An Optical Bandpass Filter is used to realize single-sideband modulation of the probe light by removing one of the first-order sidebands, as well as to reject the control light. After detecting by a photodetector, the phase of the recovered microwave signal is continuously tunable by adjusting the power of the control light. The proposed approach is theoretically analyzed and experimentally verified. A full 360° tunable phase shift is realized over an ultra-wideband frequency range from 8 to 38 GHz when the power of the control light is tuned from 0 to 570 mW.

  • photonic assisted microwave phase shifter using a dmzm and an Optical Bandpass Filter
    Optics Express, 2014
    Co-Authors: Wen Hui Sun, Wenting Wang, Lixian Wang, Jianguo Liu, Ninghua Zhu
    Abstract:

    We propose and demonstrate a photonic-assisted wideband 360° microwave phase shifter based on a conventional dual-drive Mach-Zehnder modulator (DMZM) and an Optical Bandpass Filter (OBPF). The two arms of the DMZM are driven by the fundamental microwave signal to be phase shifted and its frequency doubled component, respectively. The OBPF followed after the DMZM is used to remove the Optical carrier and the sidebands at either side of the Optical carrier. As a result, only two sidebands corresponding to the fundamental microwave signal and its frequency doubled component, respectively, are left. Moreover, the phase shift between the two sidebands can be continuously tunable by adjusting the bias voltage of the DMZM. This phase shift is mapped to the fundamental microwave signal which is recovered by beating the two sidebands in a photodetector (PD). The proposed approach is theoretically analyzed and experimentally verified.

  • Continuously Tunable Microwave Photonic Notch Filter With a Complex Coefficient
    IEEE Photonics Journal, 2011
    Co-Authors: Ninghua Zhu, Lixian Wang
    Abstract:

    This paper presents a continuously tunable microwave photonic notch Filter with a complex coefficient. The complex coefficient is generated using a radio-frequency (RF) phase shifter that consists of a dual-parallel Mach-Zehnder modulator (DPMZM) and a tunable Optical Bandpass Filter (TBPF). By simply controlling the bias voltage of the DPMZM, the frequency response of the Filter can be continuously tuned over a full free spectral range (FSR) without changing the shape of the frequency response.

H.j.s. Dorren - One of the best experts on this subject based on the ideXlab platform.

Dexiu Huang - One of the best experts on this subject based on the ideXlab platform.

  • bandwidth and wavelength tunable Optical Bandpass Filter based on silicon microring mzi structure
    Optics Express, 2011
    Co-Authors: Yunhong Ding, Xinliang Zhang, Liu Liu, Christophe Peucheret, Dexiu Huang
    Abstract:

    A novel and simple bandwidth and wavelength-tunable Optical Bandpass Filter based on silicon microrings in a Mach-Zehnder interferometer (MZI) structure is proposed and demonstrated. In this Filter design, the drop transmissions of two microring resonators are combined to provide the desired tunability. A detailed analysis and the design of the device are presented. The shape factor and extinction ratio of the Filter are optimized by thermally controlling the phase difference between the two arms of the MZI. Simultaneous bandwidth and wavelength tunability with in-band ripple control is demonstrated by thermally tuning the resonance offset between the two microring resonators.

  • experimental study of soa based nrz to prz conversion and distortion elimination of amplified nrz signal using spectral Filtering
    Optics Communications, 2008
    Co-Authors: Jianji Dong, Xinliang Zhang, Fei Wang, Wei Hong, Dexiu Huang
    Abstract:

    Abstract We experimentally study both reshaping of nonreturn-to-zero (NRZ) signal and NRZ to pseudoreturn-to-zero (PRZ) format conversion based on self-phase modulation of a semiconductor Optical amplifier (SOA) and detuning an Optical Bandpass Filter (OBF). When an OBF with 1 nm bandwidth is blue shifted by 0.8 nm, the distortion of the amplified NRZ signal at 10 Gbit/s is shown to be eliminated completely. When an OBF with 0.32 nm bandwidth is red shifted by 0.42 nm from the carrier frequency, NRZ-to-PRZ conversion at 10 Gbit/s is obtained. A holding beam is used to suppress the SOA noise and improve the output extinction ratio (ER). The output ER of both the reshaped NRZ and the converted PRZ is larger than 10 dB when the signal wavelength is longer than 1540 nm, and an input power dynamic range from −7 dBm to 2 dBm is obtained at a signal wavelength of 1563.6 nm. The average power of the reshaped NRZ signal is about 3 dBm at an input power dynamic range of 13 dB. The amplitude fluctuation of the converted PRZ signal is around 1.6 dB.

  • ultrafast all Optical signal processing based on single semiconductor Optical amplifier and Optical Filtering
    IEEE Journal of Selected Topics in Quantum Electronics, 2008
    Co-Authors: Jianji Dong, Ping Shum, Songnian Fu, Jing Xu, Xinliang Zhang, Dexiu Huang
    Abstract:

    We propose and demonstrate several all-Optical signal-processing technologies, including wavelength conversion (WC), leading/trailing edge detection, and logic gates based on a semiconductor Optical amplifier (SOA) and a detuning Optical Bandpass Filter (OBF). The system is based on pump-probe scheme. When the pump signal is return-to-zero (RZ) format, both inverted WC and noninverted WC at 40 Gb/s are obtained, and the polarity variation is highly dependent on the OBF detuning. When the pump signal is nonreturn-to-zero (NRZ) format, both the inverted WC and leading/trailing edge detection are obtained. In the inverted WC, the OBF detuning is small, and it helps to accelerate the amplitude recovery. However, in the noninverted WC and pulse edge detection, the OBF detuning is relatively large, and it acts as frequency-amplitude conversion. Finally, we present all- Optical reconfigurable logic gates based on various nonlinearities in an SOA. The logic gates including AND, NOR/NOT, and OR are obtained by four-wave mixing, cross-gain modulation, and transient cross-phase modulation in the SOA, respectively. The NOR and OR gates are capable of operating at 40 Gb/s with the help of the OBF detuning. The XNOR gate is implemented by combining the AND output and NOR output.

  • ultrawideband monocycle generation using cross phase modulation in a semiconductor Optical amplifier
    Optics Letters, 2007
    Co-Authors: Jianji Dong, Songnian Fu, Jing Xu, Dexiu Huang, Xinliang Zhang, Ping Shum
    Abstract:

    We propose a novel scheme to generate ultrawideband (UWB) monocycle pulses based on cross-phase modulation (XPM) of a semiconductor Optical amplifier (SOA). The proposed system consists of a SOA and an Optical Bandpass Filter (OBF). Due to the XPM, a continuous wave (CW) probe signal is phase modulated by another Optical Gauss pulse in the SOA. The OBF will convert the phase modulation to intensity modulation. A pair of polarity-reversed UWB monocycle pulses is achieved by locating the probe carrier at the positive and negative linear slopes of the OBF. Both cases conform to the UWB definition of the Federal Communications Commission.

  • 40 gb s all Optical nrz to rz format conversion using single soa assisted by Optical Bandpass Filter
    Optics Express, 2007
    Co-Authors: Jianji Dong, Dexiu Huang, Xinliang Zhang, Ping Shum
    Abstract:

    We propose a novel all-Optical format conversion from nonreturn-to-zero (NRZ) to return-to-zero (RZ) based on single semiconductor Optical amplifier (SOA) and a detuning Optical Bandpass Filter (OBF). By adopting the ultrafast SOA model associated with intraband mechanism, the 40Gb/s NRZ-to-RZ format conversion is successfully demonstrated with numerical simulation. We investigate the influence of the Filter detuning, extinction ratio, conversion efficiency, output pulsewidth, and Filter bandwidth. These simulation results confirm the feasibility of our scheme. The proposed scheme is robust and potential for applications in future Optical networks.

Lixian Wang - One of the best experts on this subject based on the ideXlab platform.

  • Optical vector network analyzer based on single sideband modulation and segmental measurement
    IEEE Photonics Journal, 2014
    Co-Authors: Wei Li, Wenting Wang, Lixian Wang
    Abstract:

    We propose an Optical vector network analyzer (OVNA) based on single-sideband (SSB) modulation and segmental measurement. The motivation of this work lies in the fact that it is hard for the previous SSB-based OVNA to measure a device-under-test (DUT) with Bandpass response. In our scheme, the transmission response of the DUT is divided into several segments, which are measured one by one using the SSB modulation method. The frequency interval between adjacent segments is precisely controlled by a microwave source. The full transmission response of the DUT is obtained by combining the measured results of different segments. The adjacent segments are connected using the overlapped transmission responses. A proof-of-concept experiment was carried out to measure the transmission response of an Optical Bandpass Filter. It was successfully obtained over a frequency range of 80.05 GHz with a resolution of 25 MHz.

  • photonic assisted microwave phase shifter using a dmzm and an Optical Bandpass Filter
    Optics Express, 2014
    Co-Authors: Wen Hui Sun, Wenting Wang, Lixian Wang, Jianguo Liu, Ninghua Zhu
    Abstract:

    We propose and demonstrate a photonic-assisted wideband 360° microwave phase shifter based on a conventional dual-drive Mach-Zehnder modulator (DMZM) and an Optical Bandpass Filter (OBPF). The two arms of the DMZM are driven by the fundamental microwave signal to be phase shifted and its frequency doubled component, respectively. The OBPF followed after the DMZM is used to remove the Optical carrier and the sidebands at either side of the Optical carrier. As a result, only two sidebands corresponding to the fundamental microwave signal and its frequency doubled component, respectively, are left. Moreover, the phase shift between the two sidebands can be continuously tunable by adjusting the bias voltage of the DMZM. This phase shift is mapped to the fundamental microwave signal which is recovered by beating the two sidebands in a photodetector (PD). The proposed approach is theoretically analyzed and experimentally verified.

  • Continuously Tunable Microwave Photonic Notch Filter With a Complex Coefficient
    IEEE Photonics Journal, 2011
    Co-Authors: Ninghua Zhu, Lixian Wang
    Abstract:

    This paper presents a continuously tunable microwave photonic notch Filter with a complex coefficient. The complex coefficient is generated using a radio-frequency (RF) phase shifter that consists of a dual-parallel Mach-Zehnder modulator (DPMZM) and a tunable Optical Bandpass Filter (TBPF). By simply controlling the bias voltage of the DPMZM, the frequency response of the Filter can be continuously tuned over a full free spectral range (FSR) without changing the shape of the frequency response.

Ping Shum - One of the best experts on this subject based on the ideXlab platform.

  • ultrafast all Optical signal processing based on single semiconductor Optical amplifier and Optical Filtering
    IEEE Journal of Selected Topics in Quantum Electronics, 2008
    Co-Authors: Jianji Dong, Ping Shum, Songnian Fu, Jing Xu, Xinliang Zhang, Dexiu Huang
    Abstract:

    We propose and demonstrate several all-Optical signal-processing technologies, including wavelength conversion (WC), leading/trailing edge detection, and logic gates based on a semiconductor Optical amplifier (SOA) and a detuning Optical Bandpass Filter (OBF). The system is based on pump-probe scheme. When the pump signal is return-to-zero (RZ) format, both inverted WC and noninverted WC at 40 Gb/s are obtained, and the polarity variation is highly dependent on the OBF detuning. When the pump signal is nonreturn-to-zero (NRZ) format, both the inverted WC and leading/trailing edge detection are obtained. In the inverted WC, the OBF detuning is small, and it helps to accelerate the amplitude recovery. However, in the noninverted WC and pulse edge detection, the OBF detuning is relatively large, and it acts as frequency-amplitude conversion. Finally, we present all- Optical reconfigurable logic gates based on various nonlinearities in an SOA. The logic gates including AND, NOR/NOT, and OR are obtained by four-wave mixing, cross-gain modulation, and transient cross-phase modulation in the SOA, respectively. The NOR and OR gates are capable of operating at 40 Gb/s with the help of the OBF detuning. The XNOR gate is implemented by combining the AND output and NOR output.

  • ultrawideband monocycle generation using cross phase modulation in a semiconductor Optical amplifier
    Optics Letters, 2007
    Co-Authors: Jianji Dong, Songnian Fu, Jing Xu, Dexiu Huang, Xinliang Zhang, Ping Shum
    Abstract:

    We propose a novel scheme to generate ultrawideband (UWB) monocycle pulses based on cross-phase modulation (XPM) of a semiconductor Optical amplifier (SOA). The proposed system consists of a SOA and an Optical Bandpass Filter (OBF). Due to the XPM, a continuous wave (CW) probe signal is phase modulated by another Optical Gauss pulse in the SOA. The OBF will convert the phase modulation to intensity modulation. A pair of polarity-reversed UWB monocycle pulses is achieved by locating the probe carrier at the positive and negative linear slopes of the OBF. Both cases conform to the UWB definition of the Federal Communications Commission.

  • 40 gb s all Optical nrz to rz format conversion using single soa assisted by Optical Bandpass Filter
    Optics Express, 2007
    Co-Authors: Jianji Dong, Dexiu Huang, Xinliang Zhang, Ping Shum
    Abstract:

    We propose a novel all-Optical format conversion from nonreturn-to-zero (NRZ) to return-to-zero (RZ) based on single semiconductor Optical amplifier (SOA) and a detuning Optical Bandpass Filter (OBF). By adopting the ultrafast SOA model associated with intraband mechanism, the 40Gb/s NRZ-to-RZ format conversion is successfully demonstrated with numerical simulation. We investigate the influence of the Filter detuning, extinction ratio, conversion efficiency, output pulsewidth, and Filter bandwidth. These simulation results confirm the feasibility of our scheme. The proposed scheme is robust and potential for applications in future Optical networks.

  • single soa based all Optical adder assisted by Optical Bandpass Filter theoretical analysis and performance optimization
    Optics Communications, 2007
    Co-Authors: Jianji Dong, Ping Shum, Xinliang Zhang, Liren Zhang, Dexiu Huang
    Abstract:

    A simple and compact configuration of all-Optical adders implemented with a single semiconductor Optical amplifier (SOA) and Optical Bandpass Filter (OBF) is presented in this paper. A comprehensive SOA model is put forward to investigate the output characteristics of the all-Optical adders. The numerical simulation results demonstrate the influence of these key parameters, including input pulse peak power, pulsewidth, repetition rate, and OBF characteristics. Moreover some design rules are extracted for the proper selection of these parameters so as to ensure optimum performance. The obtained results confirm the feasibility of our configuration.