A5101587852- Optical Network Technologies
- Advanced Photonic Communication Systems
- Semiconductor Lasers and Optical Devices
- Advanced Fiber Laser Technologies
- Optical measurement and interference techniques
- Advanced Measurement and Metrology Techniques
- PAPR reduction in OFDM
- Advanced Optical Network Technologies
- Photonic and Optical Devices
- Image Processing Techniques and Applications
- Advancements in Photolithography Techniques
- Infant Development and Preterm Care
- Advanced Image and Video Retrieval Techniques
- Image Retrieval and Classification Techniques
- Children's Physical and Motor Development
- Photorefractive and Nonlinear Optics
- Solid State Laser Technologies
- Attention Deficit Hyperactivity Disorder
- Climate Change Policy and Economics
- Advanced optical system design
- Microbial Fuel Cells and Bioremediation
- Advanced Surface Polishing Techniques
- Chromium effects and bioremediation
- Video Analysis and Summarization
- Graphene and Nanomaterials Applications
University of St Andrews
1992-2025
Tianjin University of Technology
2025
Shenzhen Institutes of Advanced Technology
2025
Shanghai University of Sport
2022-2023
Institute of Optics and Electronics, Chinese Academy of Sciences
2011-2022
University of Chinese Academy of Sciences
2022
Central South University
2018
Chinese Academy of Sciences
2011-2017
Ministry of Environmental Protection
2012
Ministry of Ecology and Environment
2012
A 1-Tb/s single-channel coherent optical OFDM (CO-OFDM) signal consisting of continuous 4,104 spectrally-overlapped subcarriers is generated using a novel device recirculating frequency shifter (RFS). The RFS produces 320.6-GHz wide spectrum single laser with superior flatness and tone-to-noise ratio (TNR). CO-OFDM comprised 36 uncorrelated orthogonal bands achieved by adjusting the delay to an integer number symbol periods. 1- Tb/s spectral efficiency 3.3 bit/s/Hz successfully received...
Phase estimation is one of the enabling functionalities in coherent optical orthogonal frequency-division-multiplexing (CO-OFDM) receivers. In this letter, we compare pilot-aided and data-aided phase methods for a CO-OFDM transmission experiment at 8 Gb/s over 1000-km standard single-mode fiber without dispersion compensation. We also show that as few five subcarriers are sufficient
We study the transmission performance of recently proposed multiband discrete-Fourier-transform spread orthogonal frequency-division multiplexing (MB-DFT-S-OFDM) format in which each subband is essence a single-carrier signal with Nyquist bandwidth. have found that optimal bandwidth for 428-Gb/s MB-DFT-S-OFDM 15 and 3 GHz inline dispersion compensated (IDC) nondispersion (NDC) fiber links, respectively. The optimized outperforms coherent by 1 dB (0.8 dB) after 1000-km over IDC links.
A 1-Tb/s single-channel coherent optical OFDM (CO-OFDM) signal consisting of continuous 4104 spectrally-overlapped subcarriers is generated using a recirculating frequency shifter (RFS). Theoretical and experimental analysis the RFS performed to study its effectiveness in extending bandwidth. In particular, produces 320.6-GHz wide comb from single laser with superior flatness tone-to-noise ratio (TNR). The CO-OFDM consisted 36 uncorrelated orthogonal bands achieved by adjusting delay an...
1-Tb/s per channel coherent optical OFDM transmission over 600-km SSMF fiber is demonstrated assisted with a recirculating frequency shifter. Record spectral efficiency and reach achieved at rate without Raman amplification.
In this letter, we conduct analysis on the optimum design for RF-to-optical up-converter in coherent optical OFDM systems using an I/Q modulator. We first derive closed-form expressions nonlinearity modulator, represented by two-tone intermodulation products as a function of bias point and modulation index. Additionally, perform numerical simulation to identify Q-penalty excess insertion loss under various transmitter conditions. find that contrast direct-detected system, optimal modulator...
Orthogonal frequency-division multiplexing (OFDM) is a multicarrier modulation format in which the data are transmitted with set of orthogonal subcarriers. Recently, this has been actively explored field optical communications to take advantages its high spectral efficiency and resilience chromatic polarization dispersion. However, realize OFDM at 100 Gb/s beyond requires extremely electronic bandwidth for signal processing elements. In paper, we investigate orthogonal-band-multiplexed...
There is a common belief that coherent optical orthogonal frequency-division multiplexing (CO-OFDM) has inferior nonlinear performance in the fiber optic channel due to its high peak-to-average power ratio (PAPR). In this paper, we show uniqueness of chromatic dispersion fiber, properly designed CO-OFDM can, fact, possess nonlinearity advantage over single carrier (SC) for ultrahigh-speed transport at 100 Gb/s and beyond. particular, propose novel approach called multiband DFT-spread OFDM...
Coherent optical frequency-division multiplexing (CO-OFDM) is one of the promising pathways toward future ultrahigh capacity transparent networks. In this paper, numerical simulation carried out to investigate feasibility 1 Tb/s per channel CO-OFDM transmission. We find that, for signal, performance difference between single and wavelength division (WDM) transmission small. The maximum Q 13.8 13.2 dB respectively WDM also on upgrade 10-Gb/s 100-Gb/s based DWDM systems with 50-GHz spacing...
<para xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> In this letter, we analyze the transmitter design for coherent optical orthogonal frequency-division multiplexing (CO-OFDM) employing predistortion. Digital clipping and digital predistortion processes are introduced to radio frequency OFDM compensate nonlinearity effect by in-phase/quadrature modulator. We first provide a detailed description of signal processing involved in then carry out...
1-Tb/s per channel coherent optical OFDM transmission over 600-km SSMF fiber is demonstrated assisted with a recirculating frequency shifter. Record spectral efficiency and reach achieved at rate without Raman amplification.
The significance of the study British agriculture is mainly reflected in benefits brought about by introduction a policy as well its management. Firstly, UKs agricultural and management experience great to other countries, especially developing countries. Secondly, investment education training, technical support guidance farmers, has helped improve farmers skills knowledge, which turn improved efficiency production quality products. This an important inspiration for countries strengthen...
ABSTRACT To foster sustainable development, a pivotal trend lies in harnessing energy supplies that propel modern economic and societal progress. Recent advancements living materials for applications have sparked groundbreaking research area: engineered (ELEMs), which seamlessly integrate biological artificial systems efficient conversion storage. consolidate this area, herein, we summarize delve into the evolution of ELEMs. Firstly, provide an overview structural features mechanisms...
This paper aims to deal with a four-quadrant gratings alignment method benefiting from phase demodulation for proximity lithography, which combines the advantages of interferometry image processing. Both mask mark and wafer consist four sets gratings, bring convenience simplification realization coarse fine alignment. Four moiré fringes created by superposing are highly sensitive misalignment between them. And can be easily determined through demodulating fringe without any external...
A new optical parametric oscillator based on the pumping of noncritically phase-matched lithium triborate at 266 nm is reported. Tunable in UV near 314 and IR 1.74 μm, pump pulse energies 0.5 mJ (~10-ns pulses nm) are sufficient to reach oscillation threshold, depletions ~25% 3–4 times threshold obtained.
We consider Active Constellation Extension to reduce the PAPR in CO-OFDM systems. find that nonlinearity threshold is improved by 1.5 dB at a reach of 400 km SSMF fiber.
The first 107 Gbit/s coherent optical OFDM transmission over optically non-repeated and repeated multimode fibre link is experimentally demonstrated. A record performance of 10 Tb/s·km has been achieved using centre launching equalisation.
We show the first experimental demonstration of coherent optical OFDM systems (CO- OFDM). 128 subcarriers with nominal data-rate 8 Gb/s are successfully processed and recovered after 1000-km transmission through SSMF fibre without dispersion compensation.
We extended a pilot symbol frequency offset estimation scheme and applied it in combination with subcarrier compensator. Optimum system sensitivity was found up to few 100MHz offset.
We propose DFT-spread (DFT-S) OFDM within each sub-band of multiband-CO-OFDM to mitigate fiber nonlinearity. For 1000-km standard-single-mode-fiber transmission at 420-Gb/s, 32-band DFT-S CO-OFDM outperforms conventional and coherent single-carrier by 1.1 0.8 dB, respectively.
We propose DFT-spread OFDM (DFT-S-OFDM) to mitigate fiber nonlinearity in long-haul transmission systems. For 1000-km standard-single-mode-fiber at 420-Gb/s, 32-band DFT-S-OFDM outperforms conventional coherent optical-OFDM (CO-OFDM) and single-carrier by 1.1 0.8 dB, respectively.
We experimentally demonstrate optical performance monitoring through channel estimation in coherent OFDM systems without the need for separate devices. The results of OSNR, Q-factor, fiber chromatic dispersion, and PMD are presented.