The exponential growth of global data traffic has created an urgent demand for compact, energy-efficient optical transmitters capable of supporting ultra-high-speed communication.  Optical wireless communications (OWC), and in particular light fidelity (LiFi), provides a promising solution by exploiting the vast, unregulated optical spectrum, and offering improved security and energy efficiency compared to conventional radio frequency (RF) systems.  However, current LiFi transmitters rely on static optical components that limit scalability, dynamic control and integration potential.

META-LIFI tackles these challenges through the development of metasurface-integrated vertical cavity surface emitting lasers VCSELS (meta-VCSELs).  This innovative platform enables the generation of tuneable orbital angular momentum (OAM) light beams within a compact semiconductor structure, offering a transformative pathway towards next-generation high-capacity, free-space optical communication systems.

Objectives

The primary objective is to design, fabricate and characterise a Meta-VCSEL optical transmitter, capable of dynamically generating and controlling OAM beams. The specific objectives are to:

• Design and simulate metasurface-VCSEL architectures that enable real-time phase and amplitude modulation of emitted light
• Fabricate high-precision dielectric metasurfaces, optimised for integration with bottom-emitting VCSELs
• Integrate metasurfaces on-chip with VCSEL structures to produce tuneable, high-purity OAM beams
• Characterise the optical, structural and modulation performance of the transmitter for LiFi-relevant communication scenarios

Methodology

The research with META-LIFI integrates advanced nanophotonic design, micro-/nanofabrication and optical characterisation techniques, namely:

• Design and modelling – employing multi-physics simulations to optimise coupling between the VCSEL emission and the metasurface to achieve efficient OAM generation with minimal optical loss
• Fabrication – realising high-index dielectric metasurfaces using electron-beam lithography and dry etching, enabling precise sub-wavelength phase modulation
• Integration – monolithically or hybridly integrating metasurfaces with VCSELs to form compact emitters capable of producing tuneable optical vortex beams
• Characterisation – conducting optical and spectral measurements to assess beam purity, tunability and modulation bandwidth, establishing a proof-of-concept for an adaptive LiFi transmitter

The resulting Meta-VCSEL OAM transmitter represents a major advancement in photonic integration, combining compactness, scalability and reconfigurability within a single semiconductor platform.

Impact

The outcomes of META-LIFI are expected to deliver significant advances in optical communication technology and generate impact in the following areas:

• Scientific: establishment of a novel metasurface-VCSEL platform for tuneable OAM beam generation
• Technological: creation of compact, energy-efficient, scalable transmitters suitable for next-generation LiFi and free-space optical communication systems
• Industrial and societal: contribution to the realisation of intelligent, high-capacity wireless networks supporting future digital infrastructures

Project partners: Tampere University, Middle East Technical University and the LRDC at the University of Cambridge

The META-LIFI project is funded under the CHIST-ERA Programme, under Call Topic: Nano-Opto-Electro-Mechanical Systems for ICT, with support from AKA, Finland, TÜBİTAK, Turkey, and UKRI in the UK. The project duration is 36 months.