Near-Field Spectroscopy with Infrared Synchrotron Radiation Source

Abstract

We report the results of near-field spectroscopy measurements performed using a scanning near-field optical microscopy system combined with an infrared synchrotron radiation source. The infrared synchrotron radiation is a highly brilliant white light source, and is tightly focused onto the probe tip. Strong background scattering is suppressed by modulating the distance between the probe and the sample. Higher harmonic components are extracted from the scattered light using a lock-in amplifier and examined for the presence of near-field signals. Near-field spectra in the mid-infrared region are measured by loading the higher harmonic components into a Fourier transform infrared spectroscopic apparatus. A striped metal pattern with a width of 1 μm printed on a glass substrate is found to be resolved at a wavelength of 9.8 μm. [DOI: 10.1380/ejssnt.2011.63]