Painter et al. demonstrate quantum cascade laser sensor

Virginie Moreau, Raffaele Colombelli, Raviv Perahia, Oskar Painter, Luke R. Wilson, and Andrey B. Krysa (2008) Proof-of-principle of surface detection with air-guided quantum cascade lasers. Optics Express 16(9):6387-6396, 28 April 2008. CaltechAUTHORS.