A5074013462- Optical Network Technologies
- Advanced Photonic Communication Systems
- Photonic Crystal and Fiber Optics
- Semiconductor Lasers and Optical Devices
- Photonic and Optical Devices
- Advanced Fiber Laser Technologies
- Advanced Optical Network Technologies
- Advanced Fiber Optic Sensors
- Optical Wireless Communication Technologies
- Advanced Data Compression Techniques
- Orbital Angular Momentum in Optics
- Speech Recognition and Synthesis
- Gyrotron and Vacuum Electronics Research
- Digital Filter Design and Implementation
- Acoustic Wave Resonator Technologies
- Speech and Audio Processing
- Spectroscopy Techniques in Biomedical and Chemical Research
University of Southampton
2018-2024
Kasetsart University
2023-2024
We report a Nested Antiresonant Nodeless hollow-core Fiber (NANF) operating in the first antiresonant passband. The fiber has an ultrawide operational bandwidth of 700 nm, spanning 1240-1940 nm wavelength range that includes O-, S-, C- and L- telecoms bands. It minimum loss 6.6 dB/km at 1550 ≤7 between 1465-1655 ≤10 1297-1860 nm. By splicing together two structurally matched fibers by adding single mode (SMF) pigtails both ends we have produced ~1 km long span. concatenated connectorized...
Extension in the reach of 1.3 μm optical communication systems has traditionally been restricted by availability suitable low-noise fiber amplifiers. Addressing this challenge, we present first repeatered wavelength division multiplexing (WDM) experiments using a bismuth-doped exhibits 8.4 THz (50 nm) gain bandwidth O-band. WDM signals arranged either with coarse or dense spacings are transmitted over lengths single-mode fibre (SMF)-28e ranging between 100 and 140 km.
We report on what is to the best of our knowledge longest 50-Gb/s/λ O-band wavelength-division multiplexed (WDM) transmission. A pair in-house built bismuth-doped fiber amplifiers (BDFAs) and use Kramers-Kronig detection-assisted single-sideband transmission are adopted overcome loss chromatic dispersion, respectively, in a reach-extended coarse WDM (CWDM) system with channel spacing ∼10 nm. Through experiments an amplified 4×50-Gb/s/λ direct-detection based booster pre-amp BDFAs, we show...
We demonstrate U-band Raman amplification in non-zero dispersion shifted fibre, exploiting the amplified spontaneous emission of an erbium-doped fibre amplifier as a broad-bandwidth, incoherent pump for low-noise amplification. By doing so, we achieve high overall gain ∼22 dB over 3-dB bandwidth ∼2.6 THz and obtain noise figures better than 4.3 5 40 km-long, discrete configuration, forward pumped backward scenarios, respectively. The performance is also studied through transmission coherent...
We report a Nested Antiresonant Nodeless hollow-core Fiber with 700nm bandwidth (1240–1940nm) and minimum loss of 6.6dB/km at 1550nm. Penalty-free 100-Gb/s PAM4 data transmission from O- to L-band is demonstrated over ∼1km fiber.
In this article, we experimentally demonstrate dual O+C-band direct-detection wavelength division multiplexed (WDM) transmission over 50 km of standard single-mode fibre, wherein 4 × 40-Gb/s Nyquist on-off keying (OOK) modulation is used in the O-band whilst single-sideband (SSB) subcarrier (SCM) with Kramers-Kronig (KK) detection C-band. A bismuth-doped fibre amplifier (BDFA) as pre-amplifier to extend reach system. It demonstrated that exhibits superior receiver sensitivity relative C-band...
The recent emergence of bismuth-doped fiber amplifiers (BDFAs) offers the potential to transmit high-speed WDM signals over long distances in O-band spectral region, thereby greatly enhancing scope systems utilizing these wavelengths. In this paper, we present a comprehensive experimental study on several basic characteristics an BDFA based phosphosilicate optical fiber, including frequency-dependent noise figure, gain tilt (static and dynamic), transient response, polarization dependent...
Hollow-core fibers offer a range of beneficial properties for high-speed optical communication applications, including low latency, chromatic dispersion and nonlinearity. Based on system employing ∼5-km span hollow-core nested antiresonant nodeless fiber (NANF), we demonstrate in this paper, penalty-free Nyquist 4-ary pulse amplitude modulation transmission relative to the back-to-back at 80, 100 112 Gb/s over S+C+L-bands. Furthermore, using multi-carrier direct-detection orthogonal...
In this article, we report high-speed multi-band direct-detection (DD) transmission over a hollow-core nested antiresonant nodeless fiber (NANF). Thanks to the ultrawide bandwidth of NANF, demonstrate dual-band across O- and C-bands ~1-km length for first time. Eight wavelength-division multiplexed (WDM) channels were transmitted using 100-Gb/s/λ Nyquist 4-ary pulse-amplitude modulation (PAM4) signals, which best our knowledge, is highest aggregate capacity ever in DD fiber-based system....
We demonstrate WDM transmission on both a coarse and dense spacing over 100km 120km of SMF-28e, respectively, using mid-span amplification with Bismuth-doped fibre amplifier exhibiting 7THz (42nm) gain bandwidth. Negligible power penalties are observed for all signals.
The recent emergence of efficient O-band amplification technologies has enabled the consideration transmission beyond short reach. Despite being a low chromatic dispersion (CD) window, impact CD will become increasingly significant when extending reach direct-detection (DD) systems. In this work, we first numerically investigate 3-dB bandwidth single-mode fibers (SMF) and CD-restricted in intensity-modulation DD systems, confirming difference between low- high-dispersion wavelengths. We then...
We demonstrate an 80 nm bandwidth (extending from 1529 to 1609 nm), dual-stage, diode-pumped, lumped Raman amplifier using a relatively short total length (2 km) of highly nonlinear fiber. The impact Rayleigh back scattering is mitigated and the build-up thermally generated wavelength dependent noise controlled by suitably adjusting spectral gain profile in two stages. In this way high overall 27 dB with 2.6 flatness average figure 5.8 <; 1 variation achieved across full bandwidth.
Beam tracking-and-steering is crucial for the operation of high-speed, narrow beam, optical wireless communication (OWC) systems. Using a system based on two sets low-cost cameras continuous beam tracking and set mirrors steering, we demonstrate here high-capacity (>1Tbit/s) ten-channel wavelength-division multiplexed (WDM) OWC discrete multitone transmission. The results, which are achieved over 3.5-m perpendicular distance across lateral coverage up to 1.8 m, constitute best our knowledge,...
We propose a technique for modeling erbium-doped fiber amplifiers (EDFAs) in optical networks, where the amplifier unit is located at distant node outside laboratory. collect data on an point-to-point link with as only amplification stage. Different operating points are modeled using probe signals and by adjusting settings of through control network. The used to train machine learning algorithm integrated within physical EDFA model. obtained mathematical model all network links multiple...
We propose and demonstrate a bidirectional Vanilla recurrent neural network (Vanilla-RNN) based equalization scheme for O-band coarse wavelength division multiplexed (CWDM) transmission. Based on 4 × 50-Gb/s intensity modulation direct detection (IM/DD) system, we the significantly better bit error rate (BER) performance of Vanilla-RNN over conventional decision feedback equalizer (DFE) both Nyquist on-off keying (OOK) 4-ary pulse amplitude (PAM4) formats. It is shown that capable...
We present wavelength-division multiplexed coherent transmission in an O-band amplified link enabled by bismuth-doped fiber amplifiers (BDFAs). Transmission of 4 × 25 GBd DP-16QAM (4 200 Gb/s) is demonstrated over a single span 50-km length, occupying bandwidth 4.7 THz across the wavelengths 1323 nm to 1351 nm.
We demonstrate a record 1200km reach O-band transmission of 22.5GBd dual-pol QPSK signal using recirculating loop with in-line BDFA amplification and 50km spans standard single-mode fibre.
We report up to 1.165-Tb/s optical wireless WDM transmission using a wavelength-transparent beam tracking and steering system. Over 3.5-m perpendicular distance, beyond 1-Tb/s capacity was achieved across lateral coverage 1.8 m.
We implemented a bismuth-doped fiber amplifier (BDFA) based optical recirculating loop to investigate the performance of amplified O-band transmission over appreciable distances. Both single-wavelength and wavelength-division multiplexed (WDM) were studied, with variety direct-detection modulation formats. report on (a) lengths up 550 km in single-channel 50-Gb/s system operating at wavelengths ranging from 1325 nm 1350 nm, (b) rate-reach products 57.6 Tb/s-km (after accounting for forward...
Alternate-mark-inversion (AMI) has been used in the past to improve transmission performance of binary intensity modulation formats. In this work, we improved tolerance O-band 4-level pulse amplitude (PAM4) channel impairments through adoption an AMI scheme. Improvements receiver sensitivity were shown both semiconductor optical amplifier (SOA) and bismuth-doped fibre (BDFA) equipped links. We confirmed capability extend reach O-band, which was achieved mitigation nonlinear dispersive...
We demonstrate the transmission of 3 × 20 Gbaud PAM4 signals over a 360 km, field-deployed, amplified link.We compare dispersion compensation using optical phase conjugation (OPC) to compensating fibre (DCF) and find an improvement in received bit error ratio order magnitude our OPC implementation.
We utilise the alternate mark inversion (AMI) scheme to mitigate nonlinearity in O- band transmission. The results after transmission over 60km of SMF show that AMI outperforms duobinary and on-off keying formats.
We report beyond 100-Gb/s/λ adaptively-loaded discrete multitone (DMT) transmission over the S+C+L-bands using an ultra-wide bandwidth hollow-core Nested Antiresonant Modeless Fibre (NANF) with a low polarisation dependent loss. The results show up to 132.8-Gb/s penalty-free ∼lkm fibre length without optical amplification.