Quantum processing of images by continuous wave optical parametric amplification.

We have experimentally shown that a degenerate optical parametric oscillator pumped by a cw laser, inserted in a cavity having degenerate transverse modes such as a hemiconfocal or confocal cavity, and operating below the oscillation threshold in the regime of phase sensitive amplification, is able to process input images of various shapes in the quantum regime. More precisely, when deamplified, the image is amplitude squeezed; when amplified, its two polarization components are intensity correlated at the quantum level. In addition, the amplification process of the images is shown to take place in the noiseless regime.