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ENCODING and decoding images
Figure 2. a, Simplified experimental setup. A collimated blue continuous-wave diode laser( 405 nm) illuminates an object, which is Fourier imaged by a lens onto a β-Barium-Borate nonlinear crystal( 0.5 mm thick). The down-converted photon pairs have the same wavelength( 810 nm) and polarization( perpendicular to the pump). A spectral filter after the crystal removes the pump photons. A second lens Fourier images the crystal onto a single-photon-sensitive camera, here an Electron Multiplied Charge-Coupled Device( EMCCD) camera. b, Intensity and correlation images without the object and the lens in front of the crystal. c, Intensity and correlation images with only the lens. d, Intensity and correlation images with both the lens and the object.
Figure 3. Preliminary results obtained by replacing the EMCCD by a Tpx3cam camera in the quantum encodingdecoding image scheme described in Figure 1a. a, b et c, Correlations images of three different objects( cross, flower and standing cat) reconstructed from 10 seconds of acquisition. Direct intensity images are shown in inset.
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