MIT OpenCourseWarehttp://ocw.mit.edu 6.453 Quantum Optical Communication Spring 2009 For information about citing these materials or our Terms of Use, visit: http://ocw.mit.edu/terms.December 4, 2008Optical and Quantum Communications Groupwww.rle.mit.edu/qoptics6.453 Quantum Optical CommunicationLecture 22Jeffrey H. Shapiro2www.rle.mit.edu/qoptics6.453 Quantum Optical Communication - Lecture 22! Announcements! Pick up lecture notes, slides! Term papers are due in class on Tuesday, December 9th! Quantum Signatures from Parametric Interactions! Hong-Ou-Mandel dip produced by parametric downconversion! Polarization entanglement produced by parametric downconversion! Photon twins from parametric amplifiers3www.rle.mit.edu/qopticsQuantum Interference Between Single Photons! Input State to 50/50 Beam Splitter:! Output State from 50/50 Beam Splitter:4www.rle.mit.edu/qopticsHong-Ou-Mandel Interferometer! Type-II Experiment:! PPKTP: 795 nm output wavelength,Coincidence CounterIDLERw /2PSIGNALw /2PHWPT50/50ParametricDevice5www.rle.mit.edu/qopticsHong-Ou-Mandel Coincidence Dip! Average Low-Flux Coincidence Count in -Sec-Long Gate:! Low-Flux Gaussian-State Coincidence Counting Theory:6www.rle.mit.edu/qopticsPolarization-Entanglement From Downconversion! Anti-Phased Coherently-Pumped Type-II Downconverters:OPA 1OPA 2S1S1S2S2I1I1I2I2PBS(a)DC 1DC 27www.rle.mit.edu/qopticsType-II Optical Parametric Amplifier! Doubly-Resonant Operation at Frequency Degeneracy! Normally-Ordered and Phase-Sensitive Covariances:c(2)SIGNAL, w /2PPUMP, wPIDLER, w /2P50/50PUMP,IDLER,SIGNAL,8www.rle.mit.edu/qopticsPhoton Twins from a Parametric Amplifier! Signal-Minus-Idler Photon Count Difference! Unity-Quantum-Efficiency Detectionsignalidler9www.rle.mit.edu/qopticsPhoton Twins from a Parametric Amplifier! Signal-Count and Signal-Minus-Idler Count Variances10www.rle.mit.edu/qopticsComing Attractions: Lecture 23! Lecture 23:More Quantum Optical Applications! Binary optical communication with squeezed states! Phase-sensing interferometry with squeezed states! Super-dense coding with entangled states! Quantum lithography with “N00N”
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