A. Mink, S. Frankel, and R. Perlner, " Quantum Key Distribution (QKD) and Commodity Security Protocols: Introduction and Integration ", International Journal of network security and its applications, Vol. 1, No. 2, July 2009.

Lijun Ma, Oliver Slattery, Tiejun Chang and Xiao Tang, " Non-degenerated sequential time-bin entanglement generation using periodically poled KTP waveguide ", Optics Express, Vol. 17 Issue 18, pp.15799-15807 (2009).

Lijun Ma, Oliver Slattery and Xiao Tang, " Experimental study of high sensitivity infrared spectrometer with waveguide-based up-conversion detector ", Optics Express Vol. 17, Issue 16, pp. 14395–14404 (2009).

Xiao Tang, Lijun Ma, Oliver Slattery, “Single photon detection and spectral measurement in near infrared region using up-conversion technology” invited talk, presented at LPHYS09, Barcelona, Spain, July 13-17, 2009.

Lijun Ma, Oliver Slattery, Tiejun Chang and Xiao Tang, “Sequential time-bin entanglement generation using periodically poled KTP waveguide”, CLEO/ IQEC (Optical Society of America, Washington, DC, 2009), JWA85.

Xiao Tang, Lijun Ma, Oliver Slattery, “Single photon detection and spectral measurement in near infrared region using up-conversion technology” invited talk, presented at LPHYS09, Barcelona, Spain, July 13-17, 2009.

Burm Baek, Lijun Ma, Alan Mink, Xiao Tang and Sae Woo Nam, " Detector performance in long-distance quantum key distribution using superconducting nanowire single-photon detectors ", Proc. SPIE, Vol. 7320, 73200D (2009).

Oliver Slattery, Alan Mink, and Xiao Tang, " Low noise up-conversion single photon detector and its applications in quantum information systems ", Proc. of SPIE Vol. 7465, 74650W, 2009.

Oliver Slattery, Lijun Ma and Xiao Tang, " Optimization of photon pair generation in dual-element PPKTP waveguide ", Proc. of SPIE Vol. 7465, 74650K, 2009.

Oliver Slattery, Lijun Ma and Xiao Tang, “High-Speed Coincidence Photon Pair Generation by Dual-Element PPKTP Waveguide over GHz repetition rate”, submitted to Frontier in Optics 2009 (the 93rd annual meeting of Optical Society of American, San Jose, October, 2009). WERB review approved.

All Publications.

NIST QKD system at 1310 nm combines speed and distance

In the 1310-nm QKD system, the quantum key is encoded by 1310-nm photons using the B92 protocol, as shown in the figure below. The QKD system uses a custom printed circuit board with a field-programmable gate array (FPGA) to generate a random stream of quantum key data as well as to transmit and receive classical data, which will be encoded and decoded by the quantum key. The classical data is carried as an optical signal in the 1550-nm band.

NIST 1310 nm QKD system

To polarization-encode the quantum channel from the random quantum key, we first modulate a 1306-nm CW light into a 625-MHz pulse train which is evenly split into two polarization channels. Each pulse train is further modulated by one of two complementary 625-Mbit/s quantum channel data streams. The two quantum channels are combined by a 45-degree polarization-maintaining combiner and attenuated to a mean photon number of 0.1 per bit, then multiplexed with the classical channel and transmitted over a standard single-mode fiber.

At Bob, another WDM is used to demultiplex the quantum and the classical channels. The quantum channels are polarization-decoded and detected by the up-conversion single-photon detectors, generating the raw key. Bob's board informs Alice of the location of the raw key data via the classical channel. After reconciliation and error correction, Alice and Bob obtain a common version of the secure key, which is further used to encode and decode the classical signal.
In the 1310-nm QKD system we have achieved approximately 500 Kbit/s and 9.1 Kbit/s of secure-key rates at 10 km and 50 km, respectively. We also generated secure keys in real time for one-time-pad encryption at a continuous rate of 200 Kbit/s encrypted video transmission over 10 km (potentially the key rates can reach 500 Kbit/s).

The figure of merit of the 1310-nm QKD system can be described in three key characteristics. First, the dark count (noise) is small. Second, transmission of the quantum and the classical channel can be achieved using a single fiber. Third, the chromatic dispersion is nearly zero at 1310 nm for the standard single-mode fiber.

Hai Xu, Lijun Ma, Alan Mink, Barry Hershman and Xiao. Tang. "1310-nm quantum key distribution system with up-conversion pump wavelength at 1550 nm", Optics Express, Vol. 15, Issue 12, pp. 7247-7260 (June 11, 2007).