Single photon detectors are advantageous in many applications which require very high sensitivity. Single-photon avalanche diodes (SPADs) are capable of detecting single photons with a very good timing precision. SPADs are used in commercial applications such as time-of-flight imaging and in niche applications such as fluorescence lifetime imaging. SPADs can be fabricated in conventional CMOS technology which leads to low production costs and integration of electronic circuitry in the same chip.
My primary research is on novel type of SPADs which have features such as large detection volume and low junction capacitance. This is realized by integrating “current-assistance” technique with SPADs. This can lead to SPADs with improved near-infrared response, higher counting rates and negligible afterpulsing. I also research on special circuits which are used for quenching and recharging the SPADs. My secondary research is on CMOS based avalanche photo diodes (APDs) which have separate absorption and multiplication regions (SAM-APDs).