Tip-enhanced coherent anti-stokes Raman scattering for vibrational nanoimaging.
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.
Ichimura
Taro
T
Department of Applied Physics, Osaka University, Suita, Osaka 565-0871, Japan.
Hayazawa
Norihiko
N
Hashimoto
Mamoru
M
Inouye
Yasushi
Y
Kawata
Satoshi
S