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Department of Physics M. V. Lomonosov Moscow State University. Laboratory of Spontaneous Parametric Down Conversioon. High-visibility multi-photon interference for classical light. M. V . Chekhova T. Sh. Iskhakov I. N. Agafonov. Introduction.
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Department of Physics M. V. Lomonosov Moscow State University Laboratory of Spontaneous Parametric Down Conversioon High-visibility multi-photon interference for classical light M. V . Chekhova T. Sh. Iskhakov I. N. Agafonov
Introduction • Classical visibility limit for two-photon interference: 50%. • Multi-photon Interference of nonclassical light • Classical visibility limit for multi-photon Interference
Principal scheme 1 Single counts A CC 2 B 3 Double counts Triple counts
S YAG:Nd 2w GP1 CaCO3 EOM GP2 BS2 P3 A3 BS1 A2 P1 D3 A1 D2 D1 TCC Experimental set-up • Source: 532 nm, 3kHz rep. rate, pulse 5 ns • EOM: bias voltage ~ 50 Hz, 85V • Slit: 150 microns; separation 1.3 mm • BS1: 33%, BS2: 50%; P1,P3: 60 mm thick glass plates • CC: 4.2 ns window
Third-order interference Vth =70.5%, Coherent statistics two detectors moving Coherent statistics one detector moving
Third-order interference Thermal statistics two detectors moving
Hidden polarization: three-photon case 1 L CC Coherent statistics two rotating polarizers 2 R 3
Rotating disc Fourth-order interference: setup CaCO3 YAG:Nd EOM 50 Hz Canon PowerShot S2 IS 1:60 s per frame, 500 frames
Conclusions • Classical multi-photon visibility limit (81.8% for 3-photon, 94.4% for 4-photon interference) is much higher than in the two-photon case (50%). • If visibility of interference pattern is recognized as a “signature” of nonclassicality, it should exceed 81.8% in the three-photon case and 94.4% in the four-photon one.