Single photon interference
with a Fresnel biprism

Jean-François Roch
François Treussart
Philippe Grangier

Single-photon interference


Single photons emitted by the N-V colour centre are sent on a Fresnel biprism, as an incident plane wave. Each part of the BK7 glass biprism, with summit angle of 0.43°, deviates the beam by a small angle. Interference fringes appear in the intersection volume of the two separated wavefronts.

Interference patterns are detected by registering the photons one at a time, using an image intensified CCD camera (iStar, Andor Technologies) cooled at -25 °C. For each exposure time of the camera lasting a duration of 1s, three to four photons are detected on the CCD array. The image is then transfered to a buffer and saved. Each snapshot is added to the previous one. It ends in an accumulated image corresponding to 2000 acquisitions, equivalent to 6000 to 8000 detected photons. It clearly shows how the interference pattern emerges.




Movies showing the built-up of the interference pattern

Gradual build-up of the interference pattern can be observed in the animated movies presented hereafter.

Quicktime movie - recommended for best resolution.

Zip file
31.51 Mo

.avi movie - resolution is lower compared to the Quicktime movie

Zip file
5.87 Mo