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Chemical Imaging: Chemical Imaging Beyond the Diffraction Limit: Experimental Validation of the PTIR Technique (Small 3/2013)
Author(s) -
Lahiri Basudev,
Holland Glenn,
Centrone Andrea
Publication year - 2013
Publication title -
small
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.785
H-Index - 236
eISSN - 1613-6829
pISSN - 1613-6810
DOI - 10.1002/smll.201370017
Subject(s) - photothermal therapy , cantilever , nanoscopic scale , diffraction , materials science , laser , optics , chemical imaging , photothermal effect , total internal reflection , resolution (logic) , wavelength , reflection (computer programming) , optoelectronics , nanotechnology , hyperspectral imaging , physics , remote sensing , geology , computer science , composite material , programming language , artificial intelligence
Photothermal‐induced resonance for chemical imaging at the nanoscale is described by A. Centrone and co‐workers on page 439 . An AFM cantilever measures instantaneous thermal expansion induced by light absorption in a sample. A pulsed laser, tunable across the mid‐IR is used to illuminate the sample in a total internal reflection confi guration. If the laser wavelength matches the sample vibrational absorptions, the sample heats, expands, and deflects the cantilever faster than the AFM feedback. The tip deflection is proportional to the energy absorbed, and it allows extraction of spectroscopic information with nanoscale resolution, many‐fold better than the diffraction limit. Topological images and chemical images are obtained simultaneously.