1. Quantum Coherent Control with Non-classical Light Department of Physics of Complex Systems The Weizmann Institute of Science Rehovot, Israel Yaron Bromberg, Barak Dayan, Avi Pe’er, Itai Afek, Yaron Silberberg The Ultrafast Optics Group

2. 10 fs pulses @ 800 nm ~130 nm FWHM THG images of biological specimen Femtosecond Pulse Shaping SLM Phase, amplitude and polarization synthesizer Spectral plane

3. QCC with Non-classical Light Can we shape a single photon? … what does it really mean? … and what is it good for?

4. Spontaneous Parametric Down-conversion a pump photon is spontaneously converted into two lower frequency photons energy conservation momentum conservation (phase matching) non linear crystal pump signal idler

5. Continuous Broadband Down-conversion: Time-Energy Entangled Photons PUMP (cw)  (2) SIGNAL (cw) IDLER (cw) The two-photon wavefunction

6. Gate The time DIFFERENCE between the photons behaves as a fs pulse Time-Energy Entangled Photons non linear crystal pump (cw) signal (cw) idler (cw) … so lets shape the two-photon correlation function ! But electronics limits temporal resolution to ~ns Shaper

7. 1. Hong-Ou-Mandel Interference 2. Instantaneous nonlinear interaction between photons How can we get fs resolution?

8. “Measurement of Subpicosecond Time Intervals between Two Photons by Interference” C.K. Hong, Z.Y. Ou and L. Mandel, PRL 59 (1987) IDLER SIGNAL PUMP  (2) d Two-Photon Coincidence Interference : Hong-Ou-Mandel Dip Shaper

9. HOM in polarization Pump 364 nm Computer SLM Fourier Plane PBS V 1 2 H V φ 2 type-I crystals generate polarization entanglement and broad spectrum H X V Y A. V. Burlakov et. al., PRA 64, (2001)

10. Experimental Setup Pump 364 nm Computer crystals SLM Fourier Plane PBS V 1 2 H Phase-and-polarization SLM Controls independently the ±45° axes (X,Y)

11. Experimental Results B. Dayan, Y. Bromberg, I. Afek and Y. Silberberg, in preparation.

12. 1. Hong-Ou-Mandel Interference 2. nonlinear interaction between photons (instantaneous) How can we get fs resolution?

13. Coincidence detection through Sum-Frequency Generation (SFG) CW PUMP  (2) SIGNAL (CW) IDLER (CW)  (2) typical fluxSFG efficiencySFG signal Delay

14. A photon-pair per time-bin The photon-pair arrives within 1/  How many ‘single photons’ can arrive in one second ? (How high can ‘low light levels’ be ?) (n=1 photon per mode)

15. Quantum mechanical analysis of SFG - photons per mode entangled photons

16. 1995: Kimble’s group measures a slope of 1.3 at low photon numbers

17. Down-converting crystal SFG crystal pump 532nm 5W IR detector SPCM Beam dump Dispersion compensation Computer SFG with Entangled Photons PP-KTP SFG 532nm ~40,000 s -1

18. 0 Intensity Dependence of SFG with Entangled Photons "Nonlinear Interactions with an Ultrahigh Flux of Broadband Entangled Photons", B. Dayan, A. Pe’er, A.A. Friesem and Y. Silberberg, Phys. Rev. Lett. 94, 043602 (2005)

19. Down-converting crystal up-converting crystal Pump 532nm IR detector SPCM Beam dump Computer Shaping of Entangeled Photons Fourier plane SLM

20. "Temporal Shaping of Entangled Photons", A. Pe’er, B. Dayan, A.A. Friesem and Y. Silberberg, Phys. Rev. Lett. 94, 073601 (2005) Temporal shaping of the two-photon wavefunction

21. We have seen… Control of HOM interference Shaping of two-photon correlation functions Linear SFG for low light levels SFG as coincidence detection Pulse shaping offers a new tool for quantum information Pulse Shaping Nonlinear interactions