Quantum Lunch Location:
T-Division Conference Room, TA-3,
Building 123, Room 121
Quantum Institute: Visitor Schedule
The Quantum Lunch is regularly held on Thursdays in the Theoretical Division Conference Room, TA-3, Building 123, Room 121.
For more information, contact Diego Dalvit.
July 19, 2007
Andrew J. Kerman
Optical Communications Technology Group
MIT Lincoln Laboratory
Superconducting NbN-Nanowire Single Photon Detectors
I will discuss our ongoing work at MIT on single-photon detectors based on superconducting NbN nanowires. These nanometer-scale devices exploit the ultrafast nonequilibrium electronic photoresponse in ultrathin films of the highly disordered superconductor NbN to produce a photon counter of unprecedented speed and sensitivity. With better than 30 ps timing resolution, few ns reset time after a detection, and high detection efficiency (> 70% demonstrated at 1550 nm), these devices show promise as an enabling technology in a number of areas, such as high data rate optical communications, spectroscopy of ultrafast quantum phenomena in biological and solid-state physics, quantum key distribution and quantum computation, astrophysics, laser radar, and high-speed noninvasive digital circuit testing. After providing an overview of the basic operating principles of these devices, I will present some of our recent results, including investigations into their detection mechanism, detection efficiency, and reset time; improvements to their optical design; and progress towards detector arrays. I will also show results from a demonstration experiment in which we used one of these detectors as a high-data-rate photon-counting optical receiver.
This work is sponsored by the United States Air Force under Air Force Contract #FA8721-05-C-0002. Opinions, interpretations, recommendations and conclusions are those of the authors and are not necessarily endorsed by the United States Government.