Sae Woo Nam

A Mo–Cu superconducting transition-edge microcalorimeter with 4.5 eV energy resolution at 6 keV ☆

We describe a superconducting transition-edge microcalorimeter with an energy resolution of 4.5±0.1xa0eV full-width at half-maximum (FWHM) for Mn Kα X-rays from an source. The thermometer consists of a photolithographically patterned Mo–Cu superconducting proximity bilayer with a 93xa0mK transition temperature. The device is fabricated on a Si3N4 membrane patterned as a “flyswatter” to control the thermal conductance to the heat bath. The sensor is voltage biased with an on-chip shunt resistor, and the current is measured by a two-stage SQUID amplifier consisting of a single first-stage SQUID and a series-array second-stage SQUID.

Real‐Time Data‐Acquisition Platform for Pulsed Measurements

We present an inexpensive and simple data acquisition platform based on Field Programmable Gate Arrays (FPGAs) designed to acquire and characterize fast digital or analog electrical signals in real time for processing on a generic personal computer. While the instrument was designed for electrical outputs of single‐photon detectors and is suited for high photon‐counting rates, it can also be used for characterization of similar digital electrical signals from other sources and for analog signals as well. The complete description of the platform is available for download at http://physics.nist.gov/fpga.

A heterogeneous III-V / Si_3N_4 quantum photonic integration platform

We develop a heterogeneous III-V/Si3N4 integration platform for photonic integrated circuits incorporating on-chip, InAs quantum dot-based single-photon sources.

Superconducting Transition-Edge Sensors for Waveguide Coupled Single Photon Detection

We present the design and important preliminary superconducting properties of an evanescently coupled number-resolving single photon detector operating near 1550 nm that is in development for integration into a silicon-on-insulator waveguide based optical system.