Quantum Image Generation by c.w. Optical Parametric Amplification

In this paper, experimental evidence of cw amplification of images in the quantum regime, using a phase sensitive optical parametric amplification operating inside transverse degenerate cavities. Injecting various images (mismatched Gaussian modes and double slits of different orientations) at the input of the device, showed that the output image was amplitude squeezed by 30% in the regime of deamplification of a type II frequency-degenerate OPO operating below threshold in a semi-confocal cavity, when the polarization of the input image is at 45deg from the crystal axes. The authors showed also that, in the regime of amplification, the two polarization components along the signal and idler axes had quantum correlated intensity fluctuations (intensity difference fluctuations measured at 30% below the standard quantum noise level).