Thermoreflectance imaging of electronic and optoelectronic devices is a technique that offers excellent spatial and thermal resolution. The thermoreflectance technique exploits the change in material reflectivity due to a change in temperature. This approach employs a probing light source in the visible range to detect the change in magnitude of the reflected light. The relationship between the reflectivity and temperature is related by the thermoreflectance coefficient, a property of the material. Once this coefficient is determined for a specific material, the coefficient can then be used for all future measurements and calibration for each individual measurement is not necessary. The short wavelength light source provides better spatial resolution compared to other thermal imaging techniques but does require proper sample preparation for best results. This application note provides recommendations for sample preparation and measurement procedures for thermoreflectance thermal imaging using the Microsanj NT200 series high performance image analyzers.