Direct Visualization of Molecularly Thin Lubricant Films Using Low-Coherence Phase-Shifting Interferometry

We have developed a method utilizing low-coherence phase-shifting interferometry for directly visualizing molecularly thin lubricant films coated on diamond-like carbon surfaces. By introducing a high-precision feedback controlling phase-shifting system and an image subtraction technique, the method was improved to be capable of providing real-time three-dimensional measurements with a thickness resolution of sub-nanometer and a spatial resolution of several micrometers