Atmospheric thermometry for metallic surfaces by laser-induced second-harmonic generation

To the best of our knowledge we report the first demonstration of surface thermometry using laser-induced second-harmonic generation (SHG) on a realistic metallic surface at atmospheric pressure. The surface is probed with a pulsed infrared laser beam and the SHG signal is monitored in reflection. For metallic silver, the SHG signal is found to be temperature dependent in the 25-120 [degrees] C range. The current accuracy of the method is [+ or -]5 [degrees] C. Future work with platinum should permit the application of SHG thermometry to much higher surface temperatures. Key words: Nonlinear optics, second-harmonic generation, surface thermometry.