Subsurface nanoimaging by broadband terahertz pulse near-field microscopy.

Combined with terahertz (THz) time-domain spectroscopy, THz near-field microscopy based on an atomic force microscope is a technique that, while challenging to implement, is invaluable for probing low-energy light-matter interactions of solid-state and biomolecular nanostructures, which are usually embedded in background media. Here, we experimentally demonstrate a broadband THz pulse near-field microscope that provides subsurface nanoimaging of a metallic grating embedded in a dielectric film. The THz near-field microscope can obtain broadband nanoimaging of the subsurface grating with a nearly frequency-independent lateral resolution of 90 nm, corresponding to ∼ λ/3300, at 1 THz, while the AFM only provides a flat surface topography.

[1]  E. Bakkers,et al.  Nanoscale free-carrier profiling of individual semiconductor nanowires by infrared near-field nanoscopy. , 2010, Nano letters.

[2]  M. Vitiello,et al.  Device Concepts for Graphene-Based Terahertz Photonics , 2014, IEEE Journal of Selected Topics in Quantum Electronics.

[3]  Haewook Han,et al.  Terahertz Near-Field Microscope: Analysis and Measurements of Scattering Signals , 2011, IEEE Transactions on Terahertz Science and Technology.

[4]  G. Shvets,et al.  Near-Field Microscopy Through a SiC Superlens , 2006, Science.

[5]  M. Colocci,et al.  Different contrast mechanisms induced by topography artifacts in near-field optical microscopy , 2001 .

[6]  Martin Koch,et al.  THz near-field imaging , 1998 .

[7]  K. Nelson,et al.  Resonant and nonresonant control over matter and light by intense terahertz transients , 2013, Nature Photonics.

[8]  X. Zhang,et al.  Semiconductor dynamic aperture for near-field terahertz wave imaging , 2001 .

[9]  Michael Nagel,et al.  Tapered Sommerfeld wire terahertz near-field imaging , 2009 .

[10]  Oliver G Schmidt,et al.  Intersublevel spectroscopy on single InAs-quantum dots by terahertz near-field microscopy. , 2012, Nano letters.

[11]  M. Stockman,et al.  Nanofocusing of optical energy in tapered plasmonic waveguides. , 2004, Physical review letters.

[12]  Paul C. M. Planken,et al.  Electro-optic detection of subwavelength terahertz spot sizes in the near field of a metal tip , 2002 .

[13]  Michael D. Perry,et al.  Methods for fabricating arrays of holes using interference lithography , 1997 .

[14]  R. V. Aguilar,et al.  Temporal correlations of superconductivity above the transition temperature in La 2−x Sr x CuO 4 probed by terahertz spectroscopy , 2011, 1110.2097.

[15]  R. Hillenbrand,et al.  Enhanced resolution in subsurface near-field optical microscopy. , 2012, Optics express.

[16]  Gerhard Schwaab,et al.  Setup of a scanning near field infrared microscope (SNIM): imaging of sub-surface nano-structures in gallium-doped silicon. , 2006, Physical chemistry chemical physics : PCCP.

[17]  J. Aizpurua,et al.  Terahertz near-field nanoscopy of mobile carriers in single semiconductor nanodevices. , 2008, Nano letters.

[18]  A Doi,et al.  Real-time terahertz near-field microscope. , 2011, Optics express.

[19]  Antonio H. Castro Neto,et al.  Near-field spectroscopy of silicon dioxide thin films , 2011, 1110.4927.

[20]  Thomas Taubner,et al.  Nanoscale-resolved subsurface imaging by scattering-type near-field optical microscopy. , 2005, Optics express.

[21]  Thomas Feurer,et al.  Terahertz near-field microscopy of complementary planar metamaterials: Babinet's principle. , 2011, Optics express.

[22]  T. Jin,et al.  Association between Gαi2 and ELMO1/Dock180 connects chemokine signalling with Rac activation and metastasis , 2013, Nature Communications.

[23]  M. Nagel,et al.  Terahertz near-field vectorial imaging of subwavelength apertures and aperture arrays. , 2009, Optics express.

[24]  F. Keilmann,et al.  Broadband-infrared assessment of phonon resonance in scattering-type near-field microscopy , 2011 .

[25]  Lukas Novotny,et al.  Theory of Nanometric Optical Tweezers , 1997 .

[26]  Meehyun Lim,et al.  Quantitative coherent scattering spectra in apertureless terahertz pulse near-field microscopes , 2012 .

[27]  D. W. van der Weide,et al.  Spectroscopic THz near-field microscope. , 2008, Optics express.

[28]  M. Koch,et al.  Terahertz spectroscopy and imaging – Modern techniques and applications , 2011 .

[29]  Alexander Argyros,et al.  Metamaterial fibres for subdiffraction imaging and focusing at terahertz frequencies over optically long distances , 2013, Nature Communications.

[30]  F. Keilmann,et al.  Near-field probing of vibrational absorption for chemical microscopy , 1999, Nature.

[31]  R. Hillenbrand,et al.  Analytical model for quantitative prediction of material contrasts in scattering-type near-field optical microscopy. , 2007, Optics express.

[32]  Sergey I. Bozhevolnyi,et al.  Nanofocusing of electromagnetic radiation , 2013, Nature Photonics.

[33]  Terahertz probe for spectroscopy of sub-wavelength objects. , 2012, Optics express.

[34]  Alexander J. Macfaden,et al.  3 μm aperture probes for near-field terahertz transmission microscopy , 2014 .

[35]  Lyubov V. Titova,et al.  An ultrafast terahertz scanning tunnelling microscope , 2013, Nature Photonics.

[36]  R. Kersting,et al.  Terahertz imaging with nanometer resolution , 2003 .

[37]  P. Weiss,et al.  A double lamellae dropoff etching procedure for tungsten tips attached to tuning fork atomic force microscopy/scanning tunneling microscopy sensors , 2003 .

[38]  Haewook Han,et al.  Quantitative analysis and measurements of near-field interactions in terahertz microscopes. , 2011, Optics express.

[39]  E. Hendry,et al.  Carrier dynamics in semiconductors studied with time-resolved terahertz spectroscopy , 2011 .

[40]  David J. Nesbitt,et al.  Enhanced sensitivity near-field scanning optical microscopy at high spatial resolution , 1998 .