Published in September 15th issue of Optics Express :
It’s the first experimental and theoretical report of a new effect : the 3-axis subwavelength confinement of light by a high refractive index microsphere. Freely available for download !
Abstract: Latex microspheres are used as a simple and low-cost means to achieve three axis electromagnetic confinement below the standard diffraction limit. We demonstrate their use to enhance the fluorescence fluctuation detection of single molecules. Compared to confocal microscopy with high numerical aperture, we monitor a detection volume reduction of one order of magnitude below the diffraction limit together with a 5-fold gain in the fluorescence rate per molecule. This offers new opportunities for a broad range of applications in biophotonics, plasmonics, optical data storage and ultramicroscopy.
Paris September 29th – October 2nd, several talks related to my work are planned :
- 09/29 TOM1 12:50 : J. Wenger et al “Dielectric microspheres to enhance single molecule fluorescence detection”
- 10/01 TOM4 13:50 : P. Ferrand et al “Direct observation of photonic nanojets”
- 10/01 TOM3 16:45 : P. Schoen et al “Nonlinear SHG enhancement in isolated metal nanoapertures”
- 10/01 TOM4 16:45 : A. Devilez et al “Beaming light with a single dielectric microsphere”
- Poster TOM4 677 : D. Gérard et al “Single-molecule fluorescence in subwavelength apertures: enhanced emission and photokinetics alteration”
Just published in September 1 issue of Analytical Chemistry :
An inexpensive low numerical aperture lens is used instead of a costly conventional high NA microscope objective to detect single molecule fluorescence, thanks to a latex microsphere set at the lens focus. The graphs below show fluorescence intensity correlation functions obtained with a 0.25NA doublet and a 3 µm microsphere and reference correlation function with a standard water-immersion 1.2NA microscope objective and no microsphere.
We demonstrate viable FCS experiments at concentrations 1−1000 nM with different objectives costing less than $40. This offers a simple and low-cost alternative to the conventional complex microscope objectives.