Optical OFDM With Single-Photon Avalanche Diode

In this letter, an optical orthogonal frequency division multiplexing (OFDM) system based on a single-photon avalanche diode (SPAD) receiver is presented. SPAD detectors do not require a transimpedance amplifier as they operate in the Geiger mode. This poses challenges on detecting continuous data carrying signals. However, in this letter, we show that OFDM signals can indeed be detected, and the bit error ratio performances of both dc-biased optical OFDM and asymmetrically clipped optical OFDM are investigated. The investigations are carried out in the absence of background light. The results are compared with those of standard optical OFDM with convetional photodiode receivers. The SPAD-based OFDM system shows superior power efficiency over the state-of-the-art counterpart, and it can reach receiver sensitivities that are comparable with existing radio frequency systems.