1.
Safi, Hossein; Babadi, Sina; Osahon, Isaac N. O.; Sparks, Adrian; Kostakis, Ioannis; Powell, Denise; Meredith, Wyn; Missous, Mohamed; Missous, Medi; Tavakkolnia, Iman; Haas, Harald
Chip-scale beam-shaped optical wireless system for high-speed and energy-efficient connectivity Journal Article
In: Advanced Photonics Nexus, vol. 5, no. 02, 2026, ISSN: 2791-1519.
Links | BibTeX | Tags: LRDC, optical wireless communication (OWC), orthogonal frequency-division multiplexing, Photonics, vertical-cavity surface-emitting lasers
@article{safi_chip-scale_2026,
title = {Chip-scale beam-shaped optical wireless system for high-speed and energy-efficient connectivity},
author = {Hossein Safi and Sina Babadi and Isaac N. O. Osahon and Adrian Sparks and Ioannis Kostakis and Denise Powell and Wyn Meredith and Mohamed Missous and Medi Missous and Iman Tavakkolnia and Harald Haas},
url = {https://www.spiedigitallibrary.org/journals/advanced-photonics-nexus/volume-5/issue-02/026018/Chip-scale-beam-shaped-optical-wireless-system-for-high-speed/10.1117/1.APN.5.2.026018.full},
doi = {10.1117/1.APN.5.2.026018},
issn = {2791-1519},
year = {2026},
date = {2026-03-01},
urldate = {2026-03-18},
journal = {Advanced Photonics Nexus},
volume = {5},
number = {02},
keywords = {LRDC, optical wireless communication (OWC), orthogonal frequency-division multiplexing, Photonics, vertical-cavity surface-emitting lasers},
pubstate = {published},
tppubtype = {article}
}
2.
Osahon, Isaac N. O.; Kostakis, Ioannis; Powell, Denise; Meredith, Wyn; Missous, Mohamed; Haas, Harald; Tang, Jianming; Rajbhandari, Sujan
Neural Network Equalisation for High-Speed Eye-Safe Optical Wireless Communication with 850 nm SM-VCSELs Journal Article
In: Photonics, vol. 11, no. 8, pp. 772, 2024, ISSN: 2304-6732, (Publisher: Multidisciplinary Digital Publishing Institute).
Abstract | Links | BibTeX | Tags: digital equalisation, multilayer perceptron, multilevel pulse amplitude modulation, neural network, optical wireless communications, vertical-cavity surface-emitting lasers
@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}
}
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.