The neaSNOM system allows for recording infrared spectra with a thermal source at a resolution that is 100 times better than in conventional FT-IR infrared spectroscopy.
The absorption of infrared radiation is characteristic for the chemical composition and structure of materials. Infrared spectroscopy has thus become an important tool for characterizing and identifying materials and is widely applied in different sciences and technologies including materials sciences and biomedical diagnostics. However, with conventional optical instruments, such as Fourier-transform (FTIR) infrared spectrometers, the light cannot be focused to spot sizes below several micrometers.
Infrared nanospectroscopy with a thermal source based on the neaSNOM system enables infrared spectroscopy at a resolution far below the diffraction limit. The sketch shows an atomic force microscope tip probing a sample. The tip is illuminated with the broadband infrared radiation from of a thermal source and the backscattered light is analyzed with a Fourier-transform spectrometer, yielding local infrared spectra with a spatial resolution better than 100 nm. The displayed graph shows local infrared spectra of differently processed oxides in an industrial semiconductor device.
In future, the technique could be applied for analyzing the local chemical composition and structure of nanoscale materials in polymer composites, semiconductor devices, minerals or biological tissue.