Sub-Shot-Noise Quntum Imaging
speaker: Ivano Ruo Berchera (INRIM)abstract: We exploited spatial quantum correlation between twin beams generated by Parametric Down Conversion (PDC) for realizing sub-shot -noise quantum imaging of weak absorbing objects. The idea of quantum imaging consists in measuring the intensity pattern on one branch of PDC, where an object has been inserted, and then subtracting the correlated noise pattern measured in the other branch that does not interact with the object. The image of the object, previously hidden in the noise, can be restored because the noise has been washed away by the subtraction. The method, proposed theoretically few years ago, has never been realized before, because of the difficulties of measuring a level of spatial correlation under the standard quantum limit. In Phys. Rev. Lett. 102, 213620(2009) we showed that this limit can be achieved, by using a low noise CCD array, loss-limited optical channel and a control of the coherence area of PDC. Moreover, very recently we realized a real sub-shot noise imaging experiment showing an improvement of the signal to noise ratio from 30% to 70% with respect to the classical imaging schemes operating at the same illumination level.
timetable:
Thu 5 Nov, 18:00 - 18:30, Aula Dini
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