Probing thermal evanescent waves on dielectric surfaces

Our passive near-field microscope probes thermal evanescent waves due to local phenomena on material´s surface. With the microscope, we study dielectric samples since they have surface phonon resonances whose resonance wavelengths are very close to our detection wavelength. From the results, GaAs, SiC, and AlN show reasonable signals due to thermal fluctuations, whereas GaN show very unique characteristics. In this report, we show and discuss the results.