Institut des
NanoSciences de Paris
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Nanostructures and optics

Fluorescence microscopes

Contact : Agnès Maitre

These two microscopes are used to study the fluorescence of single nanocrystals.

We can work in the visible and near-IR ranges with appropriate sets of optics and filters.

The sample is excited by a laser (400, 450 or 600 nm, pulsed or continuous) or a mercury lamp (line at 436 nm).

Fluorescence can be directed towards a CCD camera to image a portion of the sample, or a 100 µm diaphragm which spatially filters the fluorescence from a 1-µm portion of the sample, corresponding to a single emitter. The light can then be focused onto a fiber connected to a spectrometer or onto two avalanche photodiodes in Hanbuty-Brown and Twiss configuration, connected to a Picoharp acquisition card providing intensity, lifetime and antibunching measurements with a few 100-ps resolution.

It is also possible to perform polarization analysis, either by rotating a polarizer in front of the photodiodes, or by imaging the outputs of a polarizer cube.

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A standard example of such measurements performed on our setup can be found here.