Feng Zhao

Xi`an University of Posts & Telecommunications. · Department of Measurement and Control Technology and Instruments.

We experimentally realized a high-speed nested anti-resonant nodeless fiber (NANF) transmission with the assistance of the polarization division multiplexing (PDM) and probabilistic shaping (PS) technology. In this system, a low-complexity multiple-input multiple-output (MIMO) real-valued equalizer (RVE) is integrated with decision-directed carrier...

In this Letter, we propose a dual-polarized coherent millimeter-wave system based on differential delta-sigma modulation (D-DSM) intended for long-distance wireless transmission in the W-band. The proposed system can transmit polarization-division-multiplexed (PDM) D-DSM signals with modulation orders up to 4194304QAM over a wireless channel for 4....

We experimentally demonstrated Chromatic Dispersion (CD) robust Delta-Sigma Modulation (DSM) for high-order QAM mobile fronthaul. By using Duobinary (DB) encoding technology, the anti-dispersion ability of the DSM signal is effectively enhanced. At the same time, the DB coding technology can compress the signal bandwidth to a certain extent, thereb...

Photonics-assisted generation of millimeter-wave (MMW) signals can support larger modulation bandwidths compared with electronic algorithms so that it is considered as a key technology for future Radio-over-Fiber (RoF) communications. Meanwhile, multi-input multi-output (MIMO) system can concentrate the signal energy in an extremely narrow beam in...

The Carrier-less Amplitude and Phase (CAP) modulation is an advanced modulation technology with the advantages of high spectrum utilization, low cost, and low complexity. In this paper, based on photonics-aided technology and envelope detection, we experimentally demonstrate the wireless transmission of 4.6 km of 8Gbaud CAP-4QAM signal and 1.2 km o...

We experimentally demonstrate ultra-large-capacity hybrid fiber and THz-Wave wireless fronthaul over 2-km hollow-core fiber and 2-m wireless distance based on 80 channel WDM and DSM, achieving CPRI-equivalent data rate of 3.12 Tbit/s.

We experimentally demonstrate a photonics-aided THz IM/DD transmission system using a large-bandwidth envelope detector and delta-sigma modulation. The proposed system can support 4096-QAM DSM modulation and simple and low-cost receiver architecture.

We implement a multi-dimensional masking encryption scheme with an ultra-large key space of 10 ¹⁴³ in a photonics-aided millimeter radio-over-fiber (ROF) system. The equivalent 1.67GBaud encrypted-4096QAM signal is successfully transmitted and decrypted over a 4.6-km wireless link in the DSM-based D-band wireless fronthaul system.

We demonstrate 32 GBaud QPSK signal transmission over a 2 m wireless range at 93.5 GHz using CMA and MRC techniques with over 7 dB gain in a photon-assisted millimeter wave 2×2 MIMO communication system.

A 4.6-km 2×2 MIMO wireless system at D-band is experimentally demonstrated with a total data rate of 200 Gbps and a record-breaking capacity-distance product of 920 Gbps·km at D-band.

We experimentally demonstrate the dual functionality of OFDM signals for both communication and sensing. Photonics-aided ISAC system in W-band achieves range-Doppler imaging with 0.0102m resolution and data rate of 48.04 Gbit/s over wireless link.

Photon-assisted generation of terahertz (THz) signals can support larger modulation bandwidths in future ultrahigh-speed wireless communication systems. Single-input–multiple-output (SIMO) or multiple-input–multiple-output (MIMO) technology effectively uses the spatial dimension to improve the quality of the received signal, such as signal-to-noise...

We propose a non-uniform-digital-analog radio-over-fiber (NUDA-RoF) scheme based on a low-complexity 4-fold symmetric non-uniform quantization method and demonstrate it experimentally in a polarization-division-multiplexed (PDM) coherent transmission system. The 50-Gbaud PDM-NUDA-RoF signal with a net rate of 391 Gb/s/λ and a record single-channel...

In this article, we have experimentally demonstrated a fiber-wireless-integration $D$ -band (110–170 GHz) transmission system. To extend the wireless transmission distance while maintaining the wireless bit rate as high as possible, we designed high-gain lens horn antenna modules consisting of a pair of dielectric plano-convex lenses and horn ant...

MXenes are a class of two-dimensional layered structure ternary metal carbide or/and nitride materials. Recently, the MXene V2CTx has demonstrated excellent long-term stability, strong saturable absorption, and fast optical-switching capability, used to generate Q-switched and ultrashort pulsed lasers. However, bound-state fiber lasers based on V2C...

In this Letter, we propose the application of delta-sigma modulation (DSM) higher-order quadrature amplitude modulation (QAM) technology in long-distance transmission of W-band wireless communication, and demonstrate, for the first time to the best of our knowledge, the wireless transmission of millimeter wave signals in the W-band based on 1-bit D...

We propose a digital-delta-sigma-modulation radio-over-fiber (DDSM-RoF) scheme for wireless fronthaul and validate it experimentally in a D-band photonics-aided RoF transmission system. The 10-Gbaud DDSM-RoF signal with a common public radio interface equivalent data rate (CPRI-EDR) of 55.8 Gb/s is successfully transmitted in a 130-GHz 4.6-km wirel...

We present a low-cost intensity-modulated direct detection (IM/DD) system for the transmission of high-order Quadrature Amplitude Modulation (QAM) signals. By adopting the 1-bit quantized Delta-sigma modulation (DSM) technology, we quantized the Discrete Multi-Tone modulation (DMT) time-domain waveform carrying the higher-order QAM signal into on-o...

We have implemented a large-capacity, long-haul, and high spectral efficiency photonics-based polarization multiplexing communication system at W-band. The signal delivery up to 119.1 Gb/s with spectral efficiency of 9.9 bit/s/Hz is achieved over a 10 km optic-fiber link and 4600 m wireless link. In our study, we utilize an orthogonal frequency div...

Terahertz (THz) photonics technique can break through the bandwidth limitation of electronic mixing method and be seamless integrated with optical access networks, which has bright prospects in future 6G broadband communication. However, due to the bottleneck of photoelectric conversion efficiency of uni-travelling photodiode (UTC-PD), the power of...

Terahertz band (0.1 to 10 THz) with high carrier frequency and large available bandwidth has become a promising candidate to meet the 100 Gbit/s or even 1 Tbit/s data rate required by the future six-generation (6G) mobile communication networks. Compared with the all-electrical methods to generate terahertz signals, the photon-assisted technology c...

We propose and experimentally verify a photonics-aided W-band millimeter wave (MMW) radio-over-fiber (RoF) polarization-multiplexed envelope detection system for high-order quadrature amplitude modulation (QAM) signals. To solve the problem of low spectral efficiency of common public radio interface (CPRI) and severe distortion of high-order QAM of...

Chromium oxide (Cr2O3) is a promising material used in the applications such as photoelectrochemical devices, photocatalysis, magnetic random access memory, and gas sensors. But, its nonlinear optical characteristics and applications in ultrafast optics have not been studied yet. This study prepares a microfiber decorated with a Cr2O3 film via magn...

We experimentally realized a 320-GHz 320-Gbps/λ terahertz (THz) radio-over-fiber (RoF) system based on a photonics-aided scheme with the help of polarization-division multiplexing (PDM) technology and multiple-input, multiple-output (MIMO) transmission. In this system, the low-complexity MIMO single-carrier frequency-domain equalizer (SCFDE) is imp...

For the first time, we successfully transmit 1.25GBaud OFDM-256QAM/1024QAM signals over 20km SMF and 400m wireless link at the terahertz band with 1-bit DSM. The BER of OFDM-256QAM/1024QAM can satisfy the FEC threshold of 3.8×10 ⁻³ /4.0×10 ⁻² .

In a photonics-aided mm-wave communication system, we successfully achieved W-band long-distance transmission of PDM-1024QAM/2048QAM signals over 4.6 km by using a PTFE lenses and Delta-Sigma Modulator (DSM).

We have experimentally demonstrated photonics-aided bidirectional full-duplex delivery of 103Gbps PS-256QAM signals over 20-km single-mode fiber wireline link and 4600 m wireless link based on the polarization-division-multiplexing scheme and advanced DSPs.

We have experimentally demonstrated, for the first time, a single-channel 50 Gbit/s net rate THz-band transmission over an 850 m wireless link, which also creates the longest wireless distance and largest distance-rate product for a photonic THz-wireless transmission in the world.

We experimentally demonstrate a W-band photon-assisted millimeter-wave transmission system using delta-sigma modulation and envelope detection. The proposed IM/DD- MMW-RoF system can support 8192 QAM signaling over a 20-meter wireless link using DSM while meeting the SD-FEC threshold of 4.2×10 ⁻² .

In this paper, a support 65536 QAM signal mobile fronthaul (MFH) architecture based on the noise transfer function (NTF)-improved delta-sigma modulation (DSM) was proposed and demonstrated by experiment. In the NTF-improved DSM, the extended Lee's rule was used to optimize the NTF generated by the Closed-Loop Analysis of Noise-Shaping Coders (CLANS...

From the perspective of wireless transmission distance in the terahertz-band (THz-band), the 10-100 m, 100-1000 m, and ≥1000 m ranges are recommended for indoor communications, medium-distance communications, and long-distance communications, respectively. However, most existing photonic terahertz communication demonstrations reported in previous s...

We have proposed and experimentally implemented a photonics-aided large-capacity long-distance mm-wave bidirectional full-duplex communication system at the W-band based on polarization multiplexing. The same radio frequency (RF) carrier source is shared by both the uplink and the downlink, and a pair of orthomode transducers (OMTs) are used to sep...

We experimentally demonstrate 2-Gbaud 4096-ary quadrature amplitude modulation (4096QAM) signal transmission over 2-m wireless distance at 370 GHz in a photonics-aided terahertz (THz)-wave communication system. By using one-bit quantized delta-sigma modulation (DSM) and photonics-aided technology, we successfully achieve the transmission of high-or...

We proposed and established a large-capacity, long-distance wireless millimeter-wave (mm-wave) signal delivery system at W-band based on photonics-aided mm-wave generation technology, polarization-division-multiplexing (PDM), and advanced devices. We demonstrated the wireless transmission of 10-Gbaud PDM-QPSK, PDM-16QAM, and PDM-PS-64QAM mm-wave si...

Photonics technology is a promising way to generate high-frequency millimeter waves, which is also a key technology to realize the convergence of fiber-optic and wireless communication. To meet the actual application requirements, kilometer-level wireless distance, large-capacity, and high-spectral-efficiency systems are urgent requirements. Based...

The MEMS array-based inertial navigation module (M-IMU) reduces the measurement singularities of MEMS sensors by fusing multiple data processing to improve its navigation performance. However, there are still existing random and fixed errors in M-IMU navigation. The calibration method calibrates the fixed error parameters of M-IMU to further improv...

In order to investigate the decay of nonadiabatic molecular unidirectional rotation (UDR) for nitrogen molecules, we measured the time-resolved rotational Doppler spectroscopy in first four revival periods after instantaneous excitation by a polarization shaped femtosecond laser. The results show that the rotational Doppler shifts decrease with inc...

Integrating sensing function is becoming a key feature in the sixth generation (6G) radio access network. In this paper, we proposed and experimentally demonstrated a novel method that integrates high-resolution radar and long-distance communication in terahertz (THz) band. The THz communication and linear frequency modulation (LFM) signals were si...

Tantalum disulfide (TaS2) has been employed for catalysis and optical switch due to its tunable band gap, strong photoluminescence, and controllable size. However, its nonlinear optical response and applications in ultrafast optics have not been exploited. In this work, TaS2 based saturable absorber (TaS2-SA) is prepared, which exhibits strong satu...

Orthogonal frequency division multiplexing (OFDM) is a promising solution in photonics-aided millimeter-wave (MMW) communication systems, which combine the features of fiber and wireless links. In such a fiber-wireless system, the broadband OFDM signals could be affected by the multipath effect, chromatic dispersion, frequency synchronization error...

The photonics-based technology has the advantages of wide bandwidth in millimeter wave (mm-wave) communication and radar sensing systems. In the present work, we propose a novel joint communication and radar sensing functions system based on photonics at the W-band. In the proposed system, the broadband linear frequency modulated (LFM) signal and h...

We successfully demonstrate 32-Gbaud Probabilistically Shaped 4096-ary Quadrature Amplitude Modulation (PS-4096QAM) TeraHertz (THz) signal wired transmission at 325 GHz over the 1-m Hollow-Core Fiber (HCF) in a photon-assisted THz-wave communication system. By employing advanced Digital Signal Processing (DSP) and the PS technique, the 352-Gbit/s l...

In this paper, we propose and experiment with a dual-functional system that can simultaneously implement vector signal generation and radar detection based on frequency quadrupling. In the experimental demonstration, a generated W-band quadrature-phase-shift-keying (QPSK) vector signal is transmitted wirelessly over 1 m with a bit-error rate (BER)...

A novel photonics-based THz band high-resolution radar sensing, and a long-distance communication system integrated architecture was proposed and experimentally demonstrated. To the best of our knowledge, 60 Gbit/s THz signals at 340 GHz band were delivered over 50 m wireless distance with an integrated 1.58 cm resolution radar for the first time.

We experimentally demonstrate 16-GBaud PS-256QAM signal transmission over 104-m wireless distance at 339 GHz in a photonics-aided THz-wave communication system, achieving a record single line rate of 124.8 Gbit/s and net SE of 6.2 bit/s/Hz.

We implement a digital chaos-based encryption scheme in a photonics-aided terahertz radio-over-fiber (ROF) system operating at 340 GHz. The encrypted PS-64QAM-OFDM signal is successfully transmitted over 20 km SSMF and 54 m wireless link.

We experimentally demonstrated the delivery of 103.2 Gb/s 4096QAM signal over 180m wireless distance at D-band employing truncated probabilistic shaping and MIMO Volterra Compensation, with the value of NGMI exceeds the threshold of 0.83

Reservoir computing (RC) is a novel computational framework derived from recurrent neural networks (RNN). It can reduce the training complexity of RNN and is suitable for time-series learning tasks. The echo state network (ESN) is one of the most popular forms of RC. In this paper, an ESN-based equalizer is applied to perform signal equalization in...

2D ternary transition metal dichalcogenides (TMDCs) have been studied widely by researchers from the fields of nanotechnology to materials science because of the extraordinary chemical/physical characteristics, and significant potential in nanoscale device applications. Here, the application of NbxRe(1−x)S2 nanosheets in ultrafast photonics is stud...

A photonics-aided dual-functional system that can simultaneously implement high-speed communication and high-resolution radar detection is proposed. In the proposed system, high-speed orthogonal frequency division multiplexing signals and broadband linear frequency modulated signals are simultaneously realized based on photonic heterodyning. Based...

A novel high birefringence hollow-core anti-resonant terahertz photonic crystal fiber based on cycloolefin copolymer (COC) is proposed. The cladding of the fiber is composed of four sector-type tubes with node-less structure. The properties of birefringence, confinement loss, effective material absorption loss, and power fraction are analyzed by us...

We performed numerical experiments to investigate the propagation of high-power optical flat-topped beams through a strongly nonlinear medium, accounting for the diffraction, nonlinearity, and multiphoton absorption capabilities of the beams. We found that the uniform irradiance distribution of flat-topped beams can remain constant near the centre...

Terahertz band has become a promising research field due to its advantages such as high frequency and large available bandwidth. In this paper, we realized the transmission of the 325 GHz 30 Gbaud terahertz quadrature phase shift keying (QPSK) signal with a bit error ratio (BER) less than the 7% hard-decision forward-error-correction (HD-FEC) thres...

The formation and breaking dynamics of dissipative solitons (DSs) are observed in a passive mode-locked fiber laser using dispersive Fourier transform technique. Q-switched instabilities are observed both in the formation of DS and the transition breaking dynamics of DSs on gradually increasing the pump power. The real time temporal and spectral dy...

The simultaneous generation of soliton molecules and singlets in an anomalous dispersion mode-locked fiber laser was investigated using the dispersive Fourier transform technique. With careful adjustment of the polarization controller and pump power, the soliton molecule, coexistence of a soliton molecule and a single soliton pulse with different d...

Millimeter-wave (mm-wave) has become an attractive technique in the fifth generation (5G) because it meets the demand of explosive increase in data traffic. In this study, we propose and demonstrate the generation of quadrature amplitude modulated (QAM) vector mm-wave signal employing optical orthogonal polarization single sideband (SSB) modulation...

Molecular unidirectional rotation (UDR) induced by femtosecond lasers has attracted significant attention in recent years. We monitored the molecular UDR for nitrogen molecules under ambient conditions in real time by observing time-resolved spectroscopic probes, based on the rotational Doppler effect. The time-dependent alignment degree of the mol...

We demonstrate the optical imaging of objects through highly scattering media using a subtractive optical Kerr gate (SOKG). The SOKG extracts ballistic light via a subtraction operation involving a speckle-suppressed image using supercontinuum illumination and a background image captured with the ballistic light temporally excluded. By using this m...

A bi-directional photonics-aided millimeter-wave (MMW) transmission system at E-band is proposed in this paper, which can be applied in future mobile networks. Only one pair of horn antennas are adopted in the experiment to support symmetrical wireless signal transmission. The center frequency of the downlink and uplink is set as 73.5 GHz and 83.5...

With the increasing demand of bandwidth, a higher capacity communication system is required for optical short link. Intensity modulation/direct detection (IM-DD) is considered as a reasonable method, due to its low cost and power consumption. In the aspect of digital signal processing (DSP), discrete Fourier transform-spread (DFT-s) precoding can b...

With the rapid development of cloud computing and other related services, higher requirements are put forward for network transmission and delay. Due to the inherent distributed characteristics of traditional networks, machine learning technology is difficult to be applied and deployed in network control. The emergence of SDN technology provides ne...

The geometrical attenuation factor (GAF) describes the effect of shadowing and masking on surfaces. The GAF is a crucial factor in achieving a high degree of realism in computer graphics and is important for the evaluation of the accuracy of the bidirectional reflectance distribution function (BRDF). The Smith GAF is a simplified algorithm that is...

We experimentally demonstrate a 40-510 GHz all-band wireless transmitter covering the Q-, V-, W-, D- and THz-band communication links simultaneously. This is the first demonstration that a single photo-mixer is used to support simultaneous multiple transmissions over millimeter and terahertz channels.

We experimentally demonstrated THz wired transmission over 1-m hollow-core fiber employing 32-Gbaud PS-4096QAM signal at 325 GHz and successfully achieved the single line rate of 352 Gbit/s and the net spectrum efficiency of 8.6 bit/s/Hz.

We experimentally demonstrate a bidirectional photonics-aided MMW transmission system at E-band (71-76 GHz and 81-86 GHz). The proposed full-duplex MMW-RoF system can support 7 GBaud PS-4096 QAM signal transmission over 2-m wireless link when satisfying the SD-FEC threshold at 4.2×10 ⁻² .

Without terahertz amplifier, we demonstrate the capability of over 54/104 meters wireless transmission with a record-breaking net data rate of 124.8/44.8 Gbit/s at THz-band by utilizing both suitable dielectric lenses and DSP algorithms.

In this paper, we show that if {\lambda }_{1},{\lambda }_{2},{\lambda }_{3} are non-zero real numbers, and at least one of the numbers {\lambda }_{1},{\lambda }_{2},{\lambda }_{3} is irrational, then the integer parts of {\lambda }_{1}{n}_{1}^{2}+{\lambda }_{2}{n}_{2}^{3}+{\lambda }_{3}{n}_{3}^{4} are prime infinitely often for integers {n}_{1},{n}...

5G mobile fronthaul (MFH) network requires data transmission with large bandwidth and ultra-low latency. Orthogonal frequency division multiplexing/offset quadrature amplitude modulation (OFDM/OQAM) passive optical network (PON) system is the 5G MFH solution with low spectrum efficiency and large bandwidth. The OFDM/OQAM-PON transmission performanc...

Microelectromechanical systems (MEMS) are widely used in the navigation field due to their low cost and easy integration. Its low positioning accuracy restricts its expansion into the high-end navigation field. To improve the performance of MEMS inertial devices, this paper proposes a nested Kalman fusion (NKF) for MEMS gyroscope array data fusion...

We use the generalized pair-wise optimization (PO) algorithm to optimize the geometrically shaped 32-ary quadrature amplitude modulation (GS-32-QAM) constellation and adopt the probabilistic fold shaping (PFS) scheme to generate the probabilistically shaped 32-QAM (PS-32-QAM) format. We present a detailed comparison among the application of GS-32-Q...

With the rapid development of microelectromechanical systems (MEMS) technology, low-cost MEMS inertial devices have been widely used for inertial navigation. However, their application range is greatly limited in some fields with high precision requirements because of their low precision and high noise. In this paper, to improve the performance of...

Currently, polarization visualization strategies are accomplished by mapping polarization information into a perceptually uniform color appearance model CAM02-UCS. However, the deviation of the CAM02-UCS space from the lightness prediction results in an inaccurate match between the polarization information and the perceptual information. In this pa...

A D-band vector millimeter wave (mm-wave) signal generation and propagation scheme employing cascaded intensity modulator (IM) and in-phase/quadrature (I/Q) modulator is proposed and implemented. In experiment, both the IM and I/Q modulator are operating on optical-carrier-suppressing (OCS) mode to generate two pairs of dual single-sideband (SSB) s...

A novel D-band vector signal generation and transmission scheme by using joint optical carrier suppression (OCS) and single sideband (SSB) modulation without a narrowband optical filter to remove the undesired optical sidebands is proposed and implemented. An intensity modulator operating on OCS mode is utilized to generate two carrier signals with...

We experimentally demonstrated single-lane 200G+ IM/DD PAM-N system at O-band using SOA and probabilistic shaping (PS) for high-speed short reach optical interconnects. 280 Gb/s PS-PAM-8 signals can transmit over 10 km SSMF.

We experimentally demonstrate a four-lane O-band IM/DD system. With the aid of semiconductor optical amplifiers and probabilistic shaping, a record bit rate of 1.12Tb/s (280Gbit/s×4) PS-PAM8 signal can be successfully transmitted over 40-km SSMF.

Time and wavelength-division multiplexed passive optical network (TWDM-PON) is expected to be the fronthaul networks of 5G, which requires low latency and large bandwidth. In this paper, we propose a Q-learning based dynamic wavelength and bandwidth allocation (DWBA) algorithm for TWDM-PON. Simulation results show that the proposed DWBA algorithm c...

A division of focal plane (DoFP) polarimeter includes an array of polarized pixels. The response characteristics of polarized pixels are directly affected by inherent defects of a DoFP polarimeter. Correspondingly, the response characteristics are crucial to correction of the inherent defects. However, research on the response characteristics is ra...