D Mehtani et al 2006 J. Opt. A: Pure Appl. Opt. 8 S183 doi:10.1088/1464-4258/8/4/S19
D Mehtani1, N Lee1, R D Hartschuh1, A Kisliuk1, M D Foster1, A P Sokolov1, F Čajko2 and I Tsukerman2
Show affiliationsResonant excitation of surface plasmons of a metal or metal-coated tip is crucial for achieving high enhancement of an optical signal with apertureless near-field optics. However, it remains a challenge to measure the optical spectrum of a tip with sub-wavelength dimensions. We present a technique based on total internal reflection microscopy to measure the optical properties of tips. A dependence of the optical resonance on the metal deposited is shown for silver-coated and gold-coated tips. These tips were also used to measure the tip-enhanced Raman spectra of silicon and a polymer blend of poly(3,4-ethylenedioxythiophene) and poly(styrenesulfonate) (PEDOT/PSS) at 514.5 and 647 nm incident wavelengths. Qualitative agreement was observed between the tip-enhanced Raman spectra and the optical resonance of the tip measured with the technique developed.
07.60.Pb Conventional optical microscopes
78.67.-n Optical properties of low-dimensional, mesoscopic, and nanoscale materials and structures
07.57.Ty Infrared spectrometers, auxiliary equipment, and techniques
Condensed matter: electrical, magnetic and optical
Issue 4 (April 2006)
Received 16 September 2005, accepted for publication 8 February 2006
Published 24 March 2006
D Mehtani et al 2006 J. Opt. A: Pure Appl. Opt. 8 S183
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