Atomic force microscope based infrared spectroscopy with multiple laser pulse repetition rate excitation

Abstract

An apparatus for characterizing sub-micron regions of a sample with an atomic force microscope (AFM) includes a probe of the AFM having a tip that interacts with a sample. A light source is provided to illuminate a tip-sample region with light pulses at least two pulse repetition rates to induce corresponding sample modifications. A detector measures corresponding probe deflection due to the induced sample modifications and generates signals corresponding to the light induced probe deflection changes. The AFM includes at least one controller, the controller extracting at least two sample responses to the light pulses from the measured probe deflection. And from the at least two sample responses, the system deduces a light induced surface pulse force that is substantially independent of damping.