ABSTRACT
This chapter focuses on the infrared (IR) region, for which there are compelling reasons to improve spatial resolution at which point spectra can be obtained. It outlines research into circumventing this so-called far-field diffraction limit by using near-field probe-based approaches. Motivations to overcome the limitation are abundant and have led to the development of systems that can image from high-energy x-rays, commonly used in medical diagnostics, to lower-than-visible energy IR wavelengths, the spectra of which have long been used for chemical identification and purity testing. The benefits of nanoscale IR spectroscopy described herein needs to be stated within the context of other vibrational spectroscopic methods. Initial attempts to directly measure thermally based IR spectra below the resolution limit of light were performed. This technique is called photothermal microspectroscopy and couples a conventional Fourier transform infrared spectrometer with an atomic force microscope.
