1.5 Gbit/s multi-channel visible light communications using CMOS-controlled GaN-based LEDs

An on-chip multi-channel visible light communication (VLC) system is realized through a blue (450 nm) GaN-based micron-size light-emitting diode (μLED) array integrated with complementary metal-oxide-semiconductor (CMOS) electronics. When driven by a custom-made CMOS driving board with 16 independent parallel data input ports, this μ LED array device is computer controllable via a standard USB interface and is capable of delivering high speed parallel data streams for VLC. A total maximum error-free data transmission rate of 1.5 Gbit/s is achieved over free space by modulating four μ LED pixels simultaneously using an on-off key non-return to zero modulation scheme. Electrical and optical crosstalk of the system has also been investigated in detail and the further optimization of CMOS design to minimize the crosstalk is proposed.