Localized thermal mapping using coherent anti-Stokes Raman spectroscopy

Coherent anti-Stokes Raman scattering (CARS) spectroscopy is explored as a tool for obtaining microscale thermal measurements. A single femtosecond oscillator is used to pump a photonic crystal fiber to provide the broadband Stokes pulse. The CARS signals from the broad OH-stretching modes between 3000 and 3600 cm(-1) are shown to correlate with temperature with an accuracy of +/- 1 degrees C for water and +/- 1.5 degrees C for phosphate-buffered saline. Local variation of temperature is mapped on a microscopic level, using black-dyed microspheres as thermal sources. (C) 2012 Society of Photo-Optical Instrumentation Engineers (SPIE). [DOI: 10.1117/1.JBO.17.8.080501]