Characterization of RGB LEDs as Emitter and Photodetector for LED-to-LED Communication

Visible Light Communication (VLC) has rapidly grown over the last decade. However, unlike RF technologies, VLC has a simplex channel since two different devices are used for transmitting and receiving. This increases the cost and complexity of the transceiver circuit when a bidirectional link is required. LED-to-LED communication is a potential solution for a half-duplex channel. It utilizes the LED as photodetector for detection. This paper practically examines the RGB LED characteristics with emphasis on responsivity, wavelength sensitivity and angular response. The LED photodetector has a bandwidth of 6 MHz, responsivity of 256 nA/mW and FWHM of 18°.