High frequency lock-in thermography using single photon detectors

Abstract

Systems, methods, and computer readable media to improve the operation of thermographic imaging systems are described. Techniques are disclosed for generating thermograms using single low-noise photon detectors. More particularly, an array of single low-noise photon detectors operating in the Geiger mode may be used to accurately identify the time delay between the application of a periodic power stimulus to a device under test and the generation of photons resulting from that stimulus. In one embodiment an array of single photon detectors may be used to time-tag each detected photon. Thereafter, a high-speed counting circuit can correlate the detected photons to the applied stimulus. When operating at the frequencies possible in the Geiger mode, such measurements permit a higher degree of spatial resolution (e.g., in the x, y and z axes) of thermal hot-spots within the device under test than prior art approaches.