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Optical processing in images using vectorial second harmonic generation

Non linear media have been used for a long time to process images. For example, up-conversion of optical images from the infrared to the visible has been proposed and realized in order to take advantage of the higher quality of CCD detectors in the visible. IMEDEA has investigated this domain at the quantum level, in the specific configuration of vectorial second harmonic generation.

They have shown, both in the intracavity and travelling wave configurations, that the up-conversion of any image to the second harmonic field was possible without distortion by sending the image on one polarisation of the fundamental wave, and a plane wave on the other. Image processing functions like contrast enhancement or contour recognition are possible with this scheme.

Furthermore, they have found that, in some circumstances, the up-conversion operation can be made without adding quantum noise to the initial image.

Reported by

ENS Laboratoire Kastler Brossel
UPMC Case 74
75252 Paris