Mid-infrared single-photon counting

Mid-infrared single-photon counting.

We report a procedure to detect mid-infrared single photons at 4.65 microm by means of a two-stage scheme based on sum-frequency generation, by using a periodically poled lithium niobate nonlinear crystal and a silicon avalanche photodiode. An experimental investigation shows that, in addition to a high timing resolution, this technique yields a detection sensitivity of 1.24 pW with 63 mW of ne...

Single Photon Avalanche Photodiodes for Near-Infrared Photon Counting

InP-based single photon avalanche diodes (SPADs) have proven to be the most practical solution currently available for many applications requiring high-performance photon counting at near-infrared wavelengths between 1.0 and 1.6 μm. We describe recent progress in the design, characterization, and modeling of InP-based SPADs, particularly with respect to the dark count rate vs. photon detection ...

Single-photon counting

High-sensitivity detectors that are able to generate an electrical signal when struck by a single photon have two main applications. The first is for tasks involving very low light levels, such as fluorescence microscopy for biological imaging, free-space optical communications or laser ranging. The second is for singlephoton counters in quantum optics, which must often capture individual photo...

Time-Correlated Single Photon Counting

Time-resolved fluorescence spectroscopy is a powerful analysis tool in fundamental physics as well as in the life sciences. Implementing it in the time domain requires recording the time dependent intensity profile of the emitted light upon excitation by a short flash of light, typically a laser pulse. While in principle, one could attempt to record the time decay profile of the signal from a s...

Near-Infrared Single-Photon Detection