Visible light communication (VLC) is an emerging technology that intends to enable high speed internet access primarily in the indoor environment and works on the principle of intensity modulation of existing solid-state lighting infrastructure often provided by light-emitting diodes (LEDs). VLC offers several key advantages over traditional radio-frequency based access networks including approximately 300 THz of license free bandwidth carried on visible wavelengths, ~10,000´ larger than that available in radio, which is also substantially oversubscribed. According to the latest forecasts, mobile data traffic is expected to grow at a compound annual growth rate of 47% between 2016–2021. Considering the highly-congested nature of the radio spectrum, a complementary solution is clearly required, and VLC is one of the leading candidates to provide the additional spectrum.

Our aims at Pi-Lab, in collaboration with the both the Communications and Information Systems (CIS) and Organic Semiconductors and Nanostructures (OSN) groups at UCL, are to disrupt the conventional approaches to VLC, which have mostly been focused on extending the data rates supported by LED infrastructure. We are developing new approaches to VLC links including the development of polymer LEDs (PLEDs), which are provided by OSN. PLEDs offer numerous advantages over their traditional counterparts including unique mechanical characteristics such as flexibility and arbitrarily shaped photoactive areas. They can be deposited in any shape or pattern and hence, it is possible to build up large matrices of devices. In turn this unlocks unique communications capabilities including massively parallel transmission. We are particularly interested in Wavelength Division Multiplexing (WDM) methods to increase data rate in VLC systems and we are designing and fabricating the optical components, including gratings and microlenses, that underpin this technology.

Funding

• EPSRC grant: EP/P006280/1, Multifunctional Polymer Light-Emitting Diodes with Visible Light Communications (MARVEL).

Publications

• Haigh, P. A. et al. Wavelength-Multiplexed Polymer LEDs: Towards 55 Mb/s Organic Visible Light Communications. IEEE J. Sel. Areas Commun. 33, 1819–1828 (2015).
• Haigh, P. A. et al. A Multi-CAP Visible-Light Communications System With 4.85-b/s/Hz Spectral Efficiency. IEEE J. Sel. Areas Commun. 33, 1771–1779 (2015).
• Haigh, P. A. et al. Multi-band Carrier-less Amplitude and Phase Modulation for Bandlimited Visible Light Communications Systems. IEEE Wirel. Commun. 22, 46–53 (2015)

• Haigh, P. A. et al. Visible light communications: real time 10 Mb/s link with a low bandwidth polymer light-emitting diode. Opt. Express 22, 2830–2838 (2014).
• Haigh, P. A. et al. A 20-Mb/s VLC Link With a Polymer LED and a Multilayer Perceptron Equalizer. Photonics Technol. Lett. IEEE 26, 1975–1978 (2014).
• Haigh, P. A. et al. A 1-Mb/s visible light communications link with low bandwidth organic components. IEEE Photonics Technol. Lett. 26, 1295–1298 (2014).
• Haigh, P. A., Ghassemlooy, Z., Rajbhandari, S., Papakonstantinou, I. & Popoola, W. Visible light communications: 170 Mb/s using an artificial neural network equalizer in a low bandwidth white light configuration. J. Light. Technol. 32, 1807–1813 (2014).
• Le, S. T. et al. 10 Mb/s visible light transmission system using a polymer light-emitting diode with orthogonal frequency division multiplexing. Opt Lett 39, 3876–3879 (2014).

• Ghassemlooy, Z. et al. Visible light communications: 3.75Mbits/s data rate with a 160kHz bandwidth organic photodetector and artificial neural network equalization [Invited]. Photon. Res. 1, 65–68 (2013).
• Haigh, P. A., Ghassemlooy, Z. & Papakonstantinou, I. 1.4-Mb/s White Organic LED Transmission System Using Discrete Multitone Modulation. Photonics Technol. Lett. IEEE 25, 615–618 (2013).
• Haigh, P. A., Ghassemlooy, Z., Papakonstantinou, I. & Le Minh, H. 2.7 Mb/s With a 93-kHz White Organic Light Emitting Diode and Real Time ANN Equalizer. Photonics Technol. Lett. IEEE 25, 1687–1690 (2013).
• Haigh, P. A., Ghassemlooy, Z., Rajbhandari, S. & Papakonstantinou, I. Visible light communications using organic light emitting diodes. Commun. Mag. IEEE 51, (2013).

• Haigh, P. et al. Exploiting Equalization Techniques for Improving Data Rates in Organic Optoelectronic Devices for Visible Light Communications. Light. Technol. J. 30, 3081–3088 (2012).