GaN based μLED drive circuit for Visible Light Communication (VLC) with improved linearity using on-chip optical feedback

Abstract

Solid-state lighting is a rapidly developing field. Visible Light Emitting Diodes (LEDs) are becoming more efficient, have high reliability and can be incorporated into many lighting applications. LED is predicted to become the main source of general illumination due to its high energy efficiency. Such source can also modulate at high speed, thus offering a prospect of illumination and communications simultaneously. Various modulation techniques have been employed such as OOK and OFDM, where the latter has shown ability to transmit into Gb/s region. However, OFDM requires high linearity response from the driver's optical power output. In this paper, we present a drive circuit for GaN μLED which employs on-chip optical feedback technique to suppress non-linearity of the optical power output from the μLED for Visible Light Communication (VLC) with OFDM modulation.