Tip-Enhanced Coherent Anti-Stokes Raman Scattering for Vibrational Nanoimaging

Abstract

An electric field enhanced by a metallic nanoprobe has locally induced coherent anti-Stokes Raman scattering (CARS) of adenine molecules in a nanometric DNA network structure. Owing to the third-order nonlinearity, the excitation of the CARS polarization is extremely confined to the end of the tip apex, resulting in a spatial resolution far beyond the diffraction limit of light. Our tip-enhanced CARS microscope visualized the DNA network structure at a specific vibrational frequency (approximately 1337 cm(-1)) corresponding to the ring-breathing mode of diazole of adenine molecules.

Light scattering under nanofocusing: Towards coherent nanoscopies

“…We wish to emphasize that these concepts are readily extendible to ultrafast and nonlinear techniques [63][64][65][66][67], as well as coherent control [68], whereby short laser pulses are efficiently converted into SPPs and nanofocused. Multidimensional correlation spectroscopies [69] may also be implemented at the nanoscale in this way, without the need for hybrid approaches [70].…”

Coherent anti-Stokes Raman scattering with single-molecule sensitivity using a plasmonic Fano resonance

“…The CARS emission was collected by an objective in transmission and analysed by a spectrometer. When the CARS polarizations are generated in a volume much smaller than its propagation wavelength, and/or in the focused laser fields, the phase matching requirements for nonlinear optics can be fulfilled automatically (|Dk  zo op| when zo ol) 16,28 .…”

Antenna-Based Optical Imaging of Single Ca2+ Transmembrane Proteins in Liquids

“…To overcome these barriers, so-called "tip-enhanced near-fieldopticalmicroscopy"(TENOM)hasbeenintroduced. [24][25][26][27][28] In contrast to aperture-type NSOM, this technique is capable of achieving superior optical resolution, but the application to biological samples in physiological conditions has yet to be demonstrated. The laser-irradiated metal tip employed in TENOM can be viewed as a special type of optical antenna.…”