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9/1/16 September 8, 2016 6.453 Quantum Optical Communication Lecture 1 Jeffrey H. Shapiro Optical and Quantum Communications Group www.rle.mit.edu/qoptics 6.453 Quantum Optical Communication Lecture 1 Handouts Syllabus,

  1. 9/1/16 September 8, 2016 6.453 Quantum Optical Communication Lecture 1 Jeffrey H. Shapiro Optical and Quantum Communications Group www.rle.mit.edu/qoptics 6.453 Quantum Optical Communication — Lecture 1 § Handouts § Syllabus, schedule/policy, probability chapter, lecture notes, slides, problem set 1 § Sign-up on class list § Introductory Remarks § Subject organization § Subject outline § Technical Overview § Optical eavesdropping tap — quadrature-noise squeezing § Action at a distance — polarization entanglement § Long-distance quantum state transmission — qubit teleportation 2 www.rle.mit.edu/qoptics 1

  2. 9/1/16 Optical Homodyne Detection — Semiclassical § Signal is weak, LO is strong Balanced Homodyne Receiver § Energy conservation § Detectors are noisy square laws § Output mean and variance 3 www.rle.mit.edu/qoptics Optical Waveguide Tap — Semiclassical § Coupler is a beam splitter Fused Fiber Coupler § Tap input is zero § Homodyne SNR at signal input § Homodyne SNR at signal output § Homodyne SNR at tap output 4 www.rle.mit.edu/qoptics 2

  3. 9/1/16 Quantum Homodyne Detection and Waveguide Tap Balanced Homodyne Receiver Fused Fiber Coupler Homodyne SNR at signal output Homodyne SNR at tap output 5 www.rle.mit.edu/qoptics Billiard-Ball Photons and the Poincaré Sphere § Polarization of -going photon: § Poincaré sphere representation § polarization measurement 6 www.rle.mit.edu/qoptics 3

  4. 9/1/16 Classical Correlation vs. Quantum Entanglement § Classically-Correlated, Randomly-Polarized Photons § Source produces photon pair with completely random r § Conditional probability given photon 1 is instead of § Maximally-Entangled Photons § Source produces photon pair with completely random r § Conditional probability given photon 1 is instead of 7 www.rle.mit.edu/qoptics Properties of Single-Photon Polarization States § Polarization cannot be perfectly measured → § Polarization cannot be perfectly cloned ← Photons can be lost in propagation: § 8 www.rle.mit.edu/qoptics 4

  5. 9/1/16 Photon Polarization States Can Be Teleported Alice Bob 9 www.rle.mit.edu/qoptics The Road Ahead: Problem Set 1, Lectures 2 and 3 § Problem Set 1 § Reviews of essential probability theory and linear algebra § Lectures 2 and 3: Fundamentals of Dirac-Notation Quantum Mechanics § Quantum systems § States as ket vectors § State evolution via Schrödinger’s equation § Quantum measurements — observables § Schrödinger picture versus Heisenberg picture 10 www.rle.mit.edu/qoptics 5

  6. MIT OpenCourseWare https://ocw.mit.edu 6.453 Quantum Optical Communication Fall 2016 For information about citing these materials or our Terms of Use, visit: https://ocw.mit.edu/terms.

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