The growing demand for high-speed data transmission and efficient energy transfer has driven the advancement of innovative communication technologies.  In physical communication systems, devices often operate with limited energy resources, and their lifespan depends on both the available energy and the power efficiency of sensor nodes.  Consequently, extending the operational lifetime of communication nodes has become a key research focus.

Energy harvesting, the process of capturing energy from ambient or external sources and converting it into electrical power, plays a crucial role in sustaining Internet of Things (IoT) devices. Within this context, simultaneous lightwave information and power transfer (SLIPT) has emerged as a promising solution in optical wireless communication (OWC) systems. Unlike traditional radio frequency (RF) systems, which rely on simultaneous wireless information and power transfer (SWIPT), SLIPT leverages the unique properties of lightwaves to utilise the largely unused optical spectrum. This approach enables high data rate transmission while minimising electromagnetic interference with RF systems, making it suitable for diverse applications in indoor, outdoor and underwater environments.

GREENCOM addresses the key challenge of limited device lifetime by advancing the performance limits of optical wireless links for simultaneous energy harvesting and communication. This innovative approach enhances system sustainability, reduces dependence on external power sources and significantly extends the operational lifetime of wireless nodes. By integrating efficient power conversion with high-speed data transmission, GREENCOM paves the way for green connectivity, unlocking the potential for energy-efficient, high-speed OWC systems that support the next generation of sustainable wireless technologies.

Objectives

With the aim of harnessing the uncharted capabilities of free-space optical technologies, as an increasingly important pillar within a green digital revolution for future sustainable and connected societies, the project objectives are to develop:

• A unique semiconductor device enabling simultaneous power harvesting and data reception, offering unprecedented photovoltaic conversion efficiency and digital data detection capabilities – Fraunhofer Institute for Solar Energy Systems (ISE)
• Advanced OWC techniques, algorithms and protocols designed to achieve optimal energy harvesting and high data rates – the University of Cambridge (LRDC)

Methodology

GREENCOM integrates semiconductor device engineering, optical system design and advanced communication protocol development to achieve simultaneous energy harvesting and high-speed data transmission, targeting 1 watt of harvested power and a 10 Gbps link data rate over a 10m distance.  To accomplish this, the system employs a multiple input, multiple output (MIMO) architecture, in which multiple optical links operate concurrently. Each link contributes to both energy harvesting and data communication, enhancing overall system robustness, throughput and energy efficiency.

Impact

The GREENCOM system enables simultaneous energy-efficient and high-speed optical wireless links by combining novel, high-efficiency photonic power converter devices with advanced communication algorithms.  It establishes a new research field in green OWC, integrating high-speed data transmission with energy harvesting.  The project also supports high data rate transmission (e.g. 10 Gb/s) over practical distances while maintaining efficient energy harvesting, paving the way for sustainable, high-performance OWC links for space, indoor, free-space and IoT applications.

Project partners: Fraunhofer Institute for Solar Energy Systems (ISE) and the LRDC at the University of Cambridge

The GREENCOM project is funded by the EPSRC for a duration of two years.