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Seminar: Wednesday, Sep 21, 2011 at 3:30pm

Single Photon Frequency Up-Conversion and its Applications in Quantum Information Research
Xiao Tang
Information Technology Laboratory, National Institute of Standards and Technology

In this talk, we will present the recent efforts at NIST on the single photon frequency upconversion technique and its applications in quantum information research.

Silicon-based single photon detectors (Si-APDs) are high efficiency and low noise detectors for visible and near visible wavelengths, but do not work at the near infrared (NIR) wavelength range where the important telecom bands (mainly 1310 and 1550 nm) are. The performance of InGaAs based detectors for NIR photons needs to be improved. Upconversion detectors provide a good alternative, in which the NIR photons are converted to visible first and then detected by a Si-APD.

The single photon upconversion technique is based on the sum frequency generation (SFG) in nonlinear optics. A few years ago, NIST adapted the optical frequency upconversion technique to develop single photon detectors for the illusive NIR photons and used the detectors in a fiber-based high speed quantum key distribution (QKD) system. Since then, the devices have been significantly improved. In the recent years, the team’s effort is focused on the applications of the up-conversion technique in quantum information research. We will briefly introduce the applications in the research areas including the QKD system, the ultra sensitive NIR spectrometer, the entangled photon source, quantum dots, and higher-order NIR photon temporal correlations. A multiple wavelength pump technique for increasing system date rates beyond the initial limitation will be mentioned. We will also point out some potential applications of the upconversion technique in future quantum information systems.

Location: Physics Bldg., Room 401