Colloquium: Sae Woo Nam

    Thursday, November 5, 2015 - 3:30pm - 5:00pm
    Meinel 307

    "Single Photon Detection Using Superconductors: Progress and Promise"


    Single-photon detectors are increasingly becoming an essential tool for a wide range of applications in physics, chemistry, biology, communications, medicine, and remote sensing.   Ideally, a single photon detector generates a measurable signal only when a single photon is absorbed.  Furthermore, the ideal detector would have 100% detection efficiency, no false positive (dark counts), and transform-limited timing resolution.  Recently, there has been tremendous progress in the development of superconducting nanowire single-photon detectors (SNSPDs or SSPDs) towards nearly ideal performance.  The SNSPD is an alternative to conventional semiconductor avalanche photodiodes (APDs) especially for wavelengths in the near-infrared region of the spectrum.  Since the first demonstration of single photon detection with a superconducting nanowire, there has been significant effort to package nanowire detectors into systems that could be used in real-world applications.  I will review a few technological breakthroughs in SNSPD designs and performance, will briefly review a few applications relevant to government/national science, security, and standards, and will describe potential future possibilities.

    Speaker Bio(s): 

    Dr. Sae Woo Nam attended the Massachusetts Institute of Technology, where he received a degree in Physics and a degree in Electrical Engineering in 1991. He did his graduate studies at Stanford University where he received two degrees in physics: M.S. (1998) and Ph.D. (1998). His thesis research focused on the development of large cryogenic detectors for direct detection of dark matter particles using superconducting transition-edge sensors for the Cryogenic Dark Matter Search experiment (CDMS). Following his degree, he was awarded an NRC Postdoctoral Fellowship at NIST to continue work on advanced applications of superconducting transition-edge sensor (TES) based detectors. The applications have included development of a high-energy resolution x-ray detector system which is being commercialized and the development of an advanced detector readout scheme that will be used in next generation ground-based sub-mm telescopes (e.g. SCUBA2). He was hired full time at NIST in 2001 to continue this and other advanced metrology work. He has been involved (both at Stanford and NIST) with the first demonstration of using TES sensors to directly detect optical photons, the first use of a TES optical photon sensor for astronomical observations, and the first use of TES detectors for photon number resolving detection in weak pulses of light at telecommunication and optical wavelengths. Recently, he has participated in the development of a superconducting qubit based on large area Josephson junctions.

    Dr. Sae Woo Nam received a 2002 PECASE (Presidential Early Career Award for Scientists and Engineers) for work on advanced photon detectors and contributions to the field of primary thermometry using Johnson noise. Dr. Nam was also recognized in 2003 as one of the “Brilliant 10” by Popular Science magazine.