Application of evanescent wave optics to the determination of absolute distance in surface force measurements using the atomic force microscope

A combined scanning near field optical/atomic force microscope (AFM) is used to obtain surface force measurements between a near field sensing tip and a tapered optical fibre surface, whilst simultaneously detecting the intensity of the evanescent field emanating from the fibre. The tapered optical fibre acts as a compliant sample to demonstrate the possible use of the near field intensity measurement system in determining ‘real’ surface separations from normal AFM surface force measurements at sub-nanometer resolution between deformable surfaces.