Institut des
NanoSciences de Paris
insp
insp
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SNOM setup

In the nanostructures and optics group, we recently installed a near field scanning optical microscope (NSOM) based on the concept of near field probes. Very much like the STM (Scanning Tunneling Microscope), some optical information only exist and can be acquired in the near field. Through the use of near field probes (for instance pulled optical fibres), NSOM microscopy can collect and study the behaviour of light at deep sub-wavelength scales. In particular, in our group we became experts in fabricating and using nanostructured tips in order to magnify the near field signal obtained. This technological increase allows us to place in a deterministic fashion an optical nanostructure in close proximity to single quantum emitters and therefore fully study the coupling between these two elements. To do so, the NSOM is connected to different kind of detectors such as APDs (avalanche photo diodes), a spectrometer and an ultra sensitive camera.

 

NSOM microscopie principles. A near field tip is placed in close proximity (less than 15 nm) to a sample in order to detect/collect evanescent waves that only exist at its surface. Doing so, a subwavelength optical information about the latter can be achieved.

 

Exemples of nanostructured tips magnifying the optical near field signal. Theirs extraordinary electromagnetic properties come from their peculiar designs, dimensions and materials.