@article{liu_ultralow_2025,

title = {Ultralow Photon Flux OWC Links Using UV-C Single-Photon Detection},

author = {Feng Liu and James Farmer and Grahame Faulkner and Jonathan J. D. McKendry and Enyuan Xie and Qianfang Zheng and Zhaoming Wang and Jianming Wang and Jordan Hill and Johannes Herrnsdorf and Martin D. Dawson and Dominic O'Brien},

url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/lpor.202401804},

doi = {10.1002/lpor.202401804},

issn = {1863-8899},

year  = {2025},

date = {2025-01-01},

urldate = {2025-10-08},

journal = {Laser & Photonics Reviews},

volume = {19},

number = {13},

pages = {2401804},

abstract = {Low photon flux optical wireless communication (OWC) links are difficult to operate under normal daylight conditions as the interference from daylight will overwhelm any signal. However, in the UV-C region of the spectrum, light from the sun is highly attenuated, offering the possibility of link operation. In this paper, ultralow photon flux OWC links using a UV-C micro-LED and a silicon photomultiplier (SiPM) based UV-C single-photon detector (SPD) are reported. A 1 megabaud per second (MB s−1) symbol rate 128-pulse-position modulation (128-PPM) link is demonstrated with 7.7 transmitted photons per bit, corresponding to 0.97 detected photon per bit. A maximum bit rate of 120 Mbit s−1 is achieved in 8-PPM links with a transmitted power of 1.7 nW. In addition, a 500 MHz single-photon link is established with a bit error rate (BER) of textbackslash4.32 textbackslashtimes 10ˆ - 2textbackslash and a measured bit rate of 2.12 Mbit s−1, showing the potential for a quantum key distribution (QKD) system operating at the UV-C region.},

note = {_eprint: https://onlinelibrary.wiley.com/doi/pdf/10.1002/lpor.202401804},

keywords = {micro-LED, optical wireless communications, silicon photomultiplier (SiPM), single-photon detector, ultralow photon flux, UV-C},

pubstate = {published},

tppubtype = {article}

}

@article{mckendry_eye_2025,

title = {Eye and skin-safe 150 Mbps Optical Wireless Communications over 1 m using UVC LEDs},

author = {Jonathan J. D. McKendry and Hichem Zimi and Yingjie Shao and Sujan Rajbhandari and Johannes Herrnsdorf and Martin D. Dawson},

url = {https://ieeexplore.ieee.org/document/11007139},

doi = {10.1109/LPT.2025.3571619},

issn = {1941-0174},

year  = {2025},

date = {2025-01-01},

urldate = {2025-10-08},

journal = {IEEE Photonics Technology Letters},

pages = {1–1},

abstract = {We demonstrate an eye and skin-safe optical wireless communication link, at a transmission distance of 1 m, using ultraviolet-C (UVC) light-emitting diodes (LEDs) emitting at 235 and 255 nm, with error-free data rates up to 150 Mbps. Irradiance levels at the receiver were maintained within eye and skin-safe exposure limits. Operating at these short wavelengths confers an improvement in received peak signal-to-noise ratio (SNR) compared to previous demonstrations around 270-280 nm, thanks to the higher permitted exposure limits at shorter UVC wavelengths.},

keywords = {Bandwidth, Current measurement, Light emitting diodes, Light-Emitting Diodes, OFDM, Optical receivers, Optical sensors, Optical transmitters, Optical variables measurement, optical wireless communications, OWC, Power measurement, Stimulated emission, Ultraviolet, UVC, Wireless communication},

pubstate = {published},

tppubtype = {article}

}

@article{osahon_neural_2024,

title = {Neural Network Equalisation for High-Speed Eye-Safe Optical Wireless Communication with 850 nm SM-VCSELs},

author = {Isaac N. O. Osahon and Ioannis Kostakis and Denise Powell and Wyn Meredith and Mohamed Missous and Harald Haas and Jianming Tang and Sujan Rajbhandari},

url = {https://www.mdpi.com/2304-6732/11/8/772},

doi = {10.3390/photonics11080772},

issn = {2304-6732},

year  = {2024},

date = {2024-08-01},

urldate = {2025-10-08},

journal = {Photonics},

volume = {11},

number = {8},

pages = {772},

publisher = {Multidisciplinary Digital Publishing Institute},

abstract = {In this paper, we experimentally illustrate the effectiveness of neural networks (NNs) as non-linear equalisers for multilevel pulse amplitude modulation (PAM-M) transmission over an optical wireless communication (OWC) link. In our study, we compare the bit-error-rate (BER) performances of two decision feedback equalisers (DFEs)—a multilayer-perceptron-based DFE (MLPDFE), which is the NN equaliser, and a transversal DFE (TRDFE)—under two degrees of non-linear distortion using an eye-safe 850 nm single-mode vertical-cavity surface-emitting laser (SM-VCSEL). Our results consistently show that the MLPDFE delivers superior performance in comparison to the TRDFE, particularly in scenarios involving high non-linear distortion and PAM constellations with eight or more levels. At a forward error correction (FEC) threshold BER of 0.0038, we achieve bit rates of textasciitilde28 Gbps, textasciitilde29 Gbps, textasciitilde22.5 Gbps, and textasciitilde5 Gbps using PAM schemes with 2, 4, 8, and 16 levels, respectively, with the MLPDFE. Comparably, the TRDFE yields bit rates of textasciitilde28 Gbps and textasciitilde29 Gbps with PAM-2 and PAM-4, respectively. Higher PAM levels with the TRDFE result in BERs greater than 0.0038 for bit rates above 2 Gbps. These results highlight the effectiveness of the MLPDFE in optimising the performance of SM-VCSEL-based OWC systems across different modulation schemes and non-linear distortion levels.},

note = {Publisher: Multidisciplinary Digital Publishing Institute},

keywords = {digital equalisation, multilayer perceptron, multilevel pulse amplitude modulation, neural network, optical wireless communications, vertical-cavity surface-emitting lasers},

pubstate = {published},

tppubtype = {article}

}