This presentation describes recent activities on ultra-high speed Optical Wireless Communications (OWC) using Gallium-Nitride micro-LEDs designed and fabricated at CEA-Leti. Micro-LEDs are one of the most promising OWC optical sources due to their high illumination efficiency and their large modulation bandwidths. Pre-liminary work focused on the implementation of a 10-μm single blue micro-LED on sapphire wafer within an experimental OWC setup, mixing software generation of direct-current optical orthogonal frequency division multiplexing (DCO-OFDM) patterns and hardware optical components for light collection, high speed photo-detection and digital acquisitions. Intensity modulation conveys DCO-OFDM waveform and direct detection is used at reception. A high current density of 25.5 kA/cm² provided a modulation bandwidth of 1.8 GHz. Associated to bit and power loading with up to a 256-QAM subcarrier modulation, it enabled a new data rate of 7.7 Gb/s, compared to the previous record of 5.37 Gb/s reached with a blue 21-μm microLED in 2016. Towards a better understanding of the micro-LED design impact on OWC performance, next investigations will study the electrical modelling of such micro-LEDs in the high frequency regime. Future works will cover the use of large arrays of more than 10 thousands micro-LEDs. The first objective is to open the way to new digital-to-optical modulations by independently driving each pixel, to remove digital-to-analogue converter and target highly integrated system-on-chips for ultra-high speed OWC transmitters. Secondly, higher emitted optical power is expected to open such technology to indoor multiple access applications where light collection and emitter-receiver alignment may not be possible anymore.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.