Zhenguo Lu - IEEE Xplore Author Profile

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This paper presents a photonic analog-to-digital converter (ADC) tailored for RF and mmWave signals, featuring down-conversion to intermediate frequency (IF) to reduce bandwidth requirements for the photodetector (PD) and ADC sampling rate. Demonstrating an operational range of 18-32 GHz, including the 5G NR band, the system achieves a maximum effective number of bits (ENOB) of 11, limited by the ...Show More
We propose and investigate two methodologies for the design and realization of scalable low-footprint multi-band antenna arrays through the interleaving of electric and magnetic currents on mutually shared radiating surfaces. In our earlier approach, we successfully engineered and fabricated a highly isolated dual-wideband prototype operating over Ku-band, respectively showcasing impedance and gai...Show More
We will present different-type InAs/InP quantum dot (QD) coherent comb lasers (CCLs) and semiconductor optical amplifiers (SOAs) around 1550 nm with their detailed technical specifications. By using those QD-CCLs and -SOAs, we have experimentally demonstrated bi-directional millimeter-wave-over-fiber wireless fronthaul transmission links and optical superchannel coherent systems, which have clearl...Show More
The phase noise of a radio frequency (RF) signal generated by beating two optical comb lines from an InAs/InP quantum-dash mode-locked laser (QD-MLL) in a radio over fiber (RoF) link is studied theoretically and experimentally. At the central office (CO), a QD-MLL with equidistant comb lines is employed. By selecting two comb lines and sending them to a remote radio unit (RRU) via an optical fiber...Show More
We have experimentally demonstrated a bidirectional radio-over-fiber (RoF) 5G new radio (NR) fronthaul transmission link based on an InAs/InP quantum dash mode-locked laser (QD-MLL), which provide low noise and highly coherent optical carriers. Two of the optical carriers are used for heterodyne based millimeter wave (MMW) RoF downlink transmission. The signal of the downlink is a 2-GBaud 16-QAM s...Show More
We have designed, epitaxy-grown, nano-fabricated and investigated several different-type InAs/InP quantum dash / dot (QD) multi-wavelength lasers (MWLs) around 1550 nm with very low relative intensity noise and ultra-narrow optical linewidth. By using those QD MWLs, we have experimentally demonstrated optical-heterodyne millimeter-wave-over-fiber fronthaul systems with high data throughput wireles...Show More
We review recent work on developing quantum dash optical frequency comb sources for applications on coherent WDM transmission as well as microwave photonic signal processing, including filtering and photonic beamforming.Show More
The performance of InP/InAs quantum dash (QDash) multi-wavelength lasers is improved through modification of the growth scheme. We demonstrate that high performance QDash lasers exhibit high quality constellation diagrams at 32 GBaud 16QAM base-band signal.Show More
The performance of InP/InAs quantum dash (QDash) and quantum dot (QDot) multi-wavelength lasers, using identical structural design, are investigated and compared to each other. The QDash lasers show a lower threshold current and cavity loss. On the other hand, the QDot lasers show higher internal quantum efficiency, as well as lower average integrated relative intensity noise (RIN) and average opt...Show More
Semiconductor monolithic mode-locked lasers (MLLs) are potential solutions for generating high-speed optical pulses in future mobile fronthaul networks in the millimeter-wave (mmW) bands. Our previous studies have investigated using buried heterostructure (BH) quantum dash (QDash) multi-wavelength lasers for photonic mmW applications. Here we present results from monolithic chip-scale ridge wavegu...Show More
The mode-locking and noise characteristics of InP/InAs quantum dash (QDash) and quantum dot (QDot) multi-wavelength lasers, showing identical structural design, operating at the C-band, are investigated and compared to each other. The QDash lasers exhibit improved repetition frequency stability with a lower threshold current and cavity loss. On the other hand, the QDot lasers show higher quality r...Show More
We develop and experimentally demonstrate a microwave photonic-based directional phased antenna array using quantum dash mode-locked laser. Thanks to the 25 GHz free spectral range, this system has higher band utilization. With these comb lines, two types of directional antenna arrays, uniform linear array (ULA) and uniform circular array (UCA), are designed and simulated. It is found that these t...Show More
We experimentally demonstrate a duplex millimeter-wave-over-fiber (MMWoF) link for duplex wireless communications using a free-running InAs/InP quantum-dash passively-mode-locked laser (QD-MLL) as a light source. The QD-MLL is able to generate a frequency comb with a comb spacing of 0.2 nm (25.08 GHz). In the downlink, a microwave vector signal at 3 GHz is modulated on one comb line and transmitte...Show More
Two microwave photonic links (MPLs) with increased transmission capacity based on coherent detection and digital signal processing are proposed. In the first MPL, two microwave vector signals at the same microwave carrier frequency are applied to a dual-drive Mach-Zehnder modulator (DD-MZM) to modulate the two signals on an optical carrier. After transmission over a single-mode fiber, the optical ...Show More
We propose and demonstrate a novel spectrum-efficient radio-over-fiber (RoF) link based on a dual-drive Mach-Zehnder modulator and coherent detection for uplink transmission of mobile fronthaul. Compared with other RoF links, the proposed RoF link offers a two-fold increase in capacity without additional optical transceivers.Show More
In this paper, we experimentally demonstrate a photonic-assisted millimeter-wave-over-fiber (MMWoF) 2×2 MIMO wireless transmission system employing a low noise quantum dash (QDash) dual-wavelength DFB laser. The 2×2 MIMO structure is realized through optical polarization multiplexing and remote heterodyning of a single optical source together with cross-polarization configuration of two pairs of a...Show More
This paper presents the performance of InAs/InP quantum dash (QDash) mode-locked lasers with different number of QDash layers. Decreasing the number of QDash layers leads to a markedly reduced threshold and improved slope efficiency. This provides insight toward the application of QDash mode-locked laser to the field of optical transmission for all-optical networks.Show More
This paper presents results from an InAs/InP quantum dot (QDot) C-band passively mode-locked laser (MLL) for frequency comb generation. By using this single-section QDot-MLL we demonstrate an aggregate line rate of over ten Tbit/s 16QAM data transmission capacity for both back-to-back (B2B) and over 100-km of standard single mode fiber (SSMF). This finding highlights the viability for InAs/InP QDo...Show More
We investigate and present a very low-profile, high-efficiency, and high-gain 2-D leaky-wave antenna (2DLWA) implemented on a high permittivity substrate operating in the millimeter-wave range, paving the way for the seamless integration of a high-gain and high-efficiency antenna with a frontend. In contrast to the typical air-filled 2DLWA, where a perturbation of the first higher-order mode (TE1/...Show More
We demonstrate real-time broadband multi-Gb/s electrical RF synthesizer-free millimeter-wave (MMW) signals generation and wireless transmission at the 5G new radio (NR) frequency band of 47 GHz based on analog radio-over-fiber (A-RoF) fronthaul. This is enabled by a low noise, highly correlated, monolithic C-band semiconductor InAs/InP quantum-dash (QDash) dual-wavelength distributed feedback (DW-...Show More
We propose and investigate an easy technique to mitigate the mutual coupling of integrated antenna elements caused by surface waves in a high-permittivity grounded dielectric substrate, which can be deployed for high-density integration of antenna and front end on a substrate. Two approaches are examined to realize the proposed concept: 1) the removal of the ground plane between two collinear ante...Show More
We propose and demonstrate a reconfigurable microwave photonics (MWP) filter with negative coefficients using a quantum dash (QDash) mode-locked laser (MML). Thanks to the large number of comb lines $(\sim 50)$ generated by the QDash-MLL, we can easily tailor the optical frequency comb (OFC) spectrum and the filter responses. The negative taps are enabled through a balanced photodiode (BPD). In th...Show More
As quantum dash laser designs gain technological maturity, there is a need to investigate performance limiting factors. We simulate monolithic ridge waveguide quantum dash (QDash) and quantum well (QW) lasers in the InGaAsP/InP-system to investigate the mechanisms limiting device performance at elevated temperatures. Our findings are compared to experimental data obtained for representative device...Show More
This paper presents an InAs/InP buried heterostructure quantum dash (QDash) mode-locked lasers operating between $\boldsymbol{S}-$ and C-bands. By using this laser, we systematically investigate the static characteristics. This provides insight toward the application of buried heterostructure QDash mode-locked laser to the field of optical transmission for all-optical networks.Show More
This paper presents a real-time demonstration of all-optical broadband photonic wireless downlink and uplink transmissions at the K-band with data rates of 16-Gb/s and 4 to 12-Gb/s, respectively. The experimental configuration is comprised of optical fiber and RF wireless channel with a successful transmission and detection of 4 GHz 16-quadrature amplitude modulated (QAM) wireless signals at 25 GH...Show More