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Local excitation and interference of surface phonon polaritons studied by near‐field infrared microscopy
Author(s) -
HUBER A.J.,
OCELIC N.,
HILLENBRAND R.
Publication year - 2008
Publication title -
journal of microscopy
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.569
H-Index - 111
eISSN - 1365-2818
pISSN - 0022-2720
DOI - 10.1111/j.1365-2818.2008.01917.x
Subject(s) - near field scanning optical microscope , optics , materials science , polariton , interference microscopy , surface phonon , interference (communication) , surface plasmon polariton , infrared , excitation , scattering , microscopy , heterodyne (poetry) , photolithography , interferometry , phonon , optoelectronics , optical microscope , physics , surface plasmon , plasmon , scanning electron microscope , channel (broadcasting) , electrical engineering , engineering , quantum mechanics , acoustics , condensed matter physics
Summary We demonstrate that mid‐infrared surface phonon polariton excitation, propagation and interference can be studied by scattering‐type near‐field optical microscopy (s‐SNOM). In our experiments we image surface phonon polaritons (SPPs) propagating on flat SiC crystals. They are excited by weakly focused illumination of single or closely spaced metal disks we fabricated on the SiC surface by conventional photolithography. SPP imaging is performed by pseudo‐heterodyne interferometric detection of infrared light scattered by the metal tip of our s‐SNOM. The pseudo‐heterodyne technique simultaneously yields optical amplitude and phase images which allows us to measure the SPP wave vector – including its sign – and the propagation length and further to study SPP interference. High resolution imaging of SPPs could be applied to investigate for example SPP focusing or heat transfer by SPPs in low dimensional nanostructures.