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Characterizing Photonic Spatial States
Sebastião Pádua
Physics Department - Federal University of Minas Gerais – Belo Horizonte - Brazil
Paraty 2009, September 08 2009
Informação Quântica
Enlight and Quantum Optics Laboratory
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Outline
• Transfer of information from the pump beam• Generation and propagation of qudits• Quantum Tomography of qubits with SLM• Progress in four photons production
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Two photon state
Angular Spectrum Transference
ks = ki = kp/2
ms = mi = 1/2
R = (rs+ri)/2
NaNa 21
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D. Prichard, et. al, Phys. Rev. Lett. (1995)
Lithography
Double-slit – proof of principleM. D’Angelo, M. V. Chekhovaand Y. Shih, Phy. Rev. Lett. 87 013692 (2001).
OBJECT: DOUBLE SLIT
Laser, = 826 nm
Laser, = 413 nm
Twin Photons = 826 nm
Optics Communications
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Quantum Tomography with a Spatial Light Modulator
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-1500 -1000 -500 0 500 1000 15000
2000
4000
6000
8000
10000
12000
14000
sfundo25 sfundo130 sf25x130 sf130x25
Cou
nts
in 5
s
Position (mm)
Phases: 0, 0 , -60.7 , 80,6
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=
The values of pi are obtained from measurements.
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=
Slits are partially blocked and phases are changed by the SLM
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LiIO3
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Laser He-Cd
LiIO3
M1
M2
CSLM
L1
L2
DoubleSlit
f
f
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Goal: 2 qubits and 2 qutrits.
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• Students: Juliana Gontijo, Wanderson Pimenta, Mariana Barros, Marco Aurélio Carvalho, Breno Teixeira – Physics Department - UFMG
• Pos-doc : Dr. José Ferraz• Prof. Marcelo Terra Cunha – Mathematics Department – UFMG
• Univ. De Concepción - Chile: Profs. Leonardo Neves, G. Lima, A. Delgado, and Carlos Saavedra
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PPKTP – SPDC – Type II
Angular Spectrum Transference
Controlling the transverse correlation in QPM parametric down-conversion, O. Cosme, A. Delgado, G. Lima, C. H. Monken and S. Pádua – arXiv: 0906.473v1(2009)[quant-ph].
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PPKTP
Quantum image formation
Image of a double-slit placed in the pump beam path and detected at the image plane by coincidence
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Profile of the laser beam and 4-photon coincidence count in the horizontal direction
SPDC state with four photons- PPKTP
Transfer of the pump angular spectrum to the four photon SPDC quantum state
Profile of the laser beam and 4-photon coincidence count in the vertical direction
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Image of a displaced wire in the pump beam path and 4-photon counts
SPDC state with four photons- PPKTP
Transfer of the pump angular spectrum to the four photon SPDC quantum state
