60 Mb/s, 2 meters visible light communications in 1 klx ambient using an unlensed CMOS SPAD receiver

Abstract

We demonstrate an optical link operating in indoor ambient lighting conditions using a CMOS single photon avalanche diode (SPAD) optical receiver and a RGB light emitting diode (LED). The high sensitivity of the SPAD receiver allows the link to operate at 2 m distance at a total 60 Mb/s and bit error rate (BER) of 1×10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">−3</sup> without lensing. The transmitter implements color shift keying (CSK) using a custom 4-channel current mode CMOS digital to analog converter (DAC). The miniaturized, low cost components employed at transmitter and receiver are suited to integration in portable electronic devices or chip-in-a-bulb respectively.