High-Speed Visible Light Communication Using GaN-Based Light-emitting Diodes With Photonic Crystals

Abstract

Recent research and progress have shown that using light-emitting diodes (LEDs) as a high-speed transmitter is a promising candidate in a high-speed data system. The photonic crystal (PhC) LED (PhCLED) can improve the performance of the devices for visible light communication (VLC) due to its unique spatial and temporal management of photonic modes. In this paper, the dynamic behaviors of PhCLEDs at both small- and large-signal modulation are studied. Room-temperature time-resolved photoluminescence (TRPL) and Raman scattering measurements were carried out to understand the photon lifetime and strain in the PhC structure. PhCLEDs demonstrate much better high-frequency performance than conventional planar LEDs. Our study also shows that the common wisdom of shrinking the mesa size of LEDs to achieve high-frequency operation has its limit since the spontaneous emission rate has to be increased accordingly to maintain high light output efficiency in VLC LEDs.