Radiometric temperature measurement with Si and InGaAs single-photon avalanche photodiode

We experimentally demonstrate the use of single-photon avalanche photodiode (SPAD) for radiometric temperature measurement. The low dark count rate CMOS SPAD and a commercial InGaAs/InP SPAD can detect the thermal radiation from a blackbody down to the temperatures of 510 and 405 K, respectively. Our work shows that current SPADs are cost-effective thermal sensors for various applications.