Optical Sciences

Biomolecules and nanostructures

The Optical Sciences group studies the interaction of light and matter. Our current focus is on detection and sensing/imaging with an emphasis on the development of integrated photonics. We are part of Twente University's Department of Science and Technology and member of the MESA+ institute.

 

Near-field effects in single molecule emission


Gersen H, Garcia-Parajo MF, Novotny L, Veerman JA, Kuipers L, Van Hulst NF
JOURNAL OF MICROSCOPY-OXFORD
vol 202: p374-p378 part 2 MAY 2001

We present the first experimental proof of the influence of a nearby nano-sized metal object o­n the angular photon emission by a single molecule. A novel angular sensitive detection scheme is implemented in an existing near-field scanning optical microscope (NSOM). The positioning accuracy (similar to1 nm) of the NSOM allows a systematic investigation of the intensity ratio between two different half-spaces as a function of the position of the metal-glass interfaces of the probe with respect to the single emitter. The observed effects are shown to be particularly strong for molecules that are excited mainly below the rims of the aperture. An excellent agreement is found between experiments and numerical simulations for these molecules. The observed angular redistribution of the angular emission of a single molecule could explain the alteration of the emission polarization observed for certain molecules in earlier experiments (Veerman et al (1999) J. Microsc. 194, 477- 482).
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