Pyroelectric Thermal Diffusion Microscope
Original Publication Date: 1982-Oct-01
Included in the Prior Art Database: 2005-Feb-10
The method detects localized thermal discontinuities in layered structures directly and measures the thermal wave rather than the associated thermoacoustic wave. Numerous publications (2-10) discuss the imaging of subsurface defects using photoacoustic, electron acoustic or thermoelastic techniques. Two types of imaging are presented: (a) Acoustic wave imaging uses an acoustic wave generated by thermoelastically using a laser or other energy source. The acoustic wave is scattered or otherwise disturbed by a defect, altering its properties. Analysis of the detected acoustic wave yields an acoustic image of the defect. (b) Thermal wave imaging uses an energy source (laser or electron beam, etc.) absorbed by the sample to produce a thermal wave. The thermal wave generates an acoustic wave thermoelastically which is detected.