Room temperature photon-counting lidar at 3  µm

Abstract

A midinfrared single-photon-counting lidar at 3 µm is presented. The 3 µm photons were upconverted to 790 nm in a periodically poled rubidium-doped K T i O P O 4 crystal through intracavity mixing inside a 1064 nm N d : Y V O 4 laser and detected using a conventional silicon single-photon avalanche detector (SPAD). The lidar system could distinguish 1 mm deep features on a diffusely reflecting target, limited by the SPAD and time-tagging electronics. This technique could easily be extended to longer wavelengths within the transparency of the nonlinear crystal.

Advances in Mid-Infrared Single-Photon Detection

“…For lidar, VIS-NIR single-photon avalanche photodiodes with high temporal resolutions are commonly used for the detection of very weak optical pulses. The extension of lidar to the MIR [4,24] allows gas concentration measurements in the molecular fingerprint region [25], as well as higher transmission through scattering media, such as fog and smog [26]. The emergence of MIR SPDs is encouraging the extension of the fluorescence imaging technique, realized in the NIR second region band exploiting superconductive single-photon detectors [27,28], to new MIR fluorescence spectroscopy schemes, with all its countless applications, such as monitoring volcanos, infrared chemiluminescence, thermal microscopy, and infrared telescopy [6].…”