News

Professor Berggren named as IEEE fellow

Congratulations to Professor Berggren on becoming an IEEE fellow, the highest grade of membership in IEEE. He has been recognized by IEEE for his contributions to nanofabrication and nanomanufacturing in the sub-10 nm regime. Read more about this award and the other MIT faculty to be named as fellows here.

Prof. Berggren becomes an AAAS Fellow

Professor Berggren has been elected as a fellow of the American Association for the Advancement of Science (AAAS) for his contributions to methods of nanofabrication, superconductive quantum circuits, photodetectors, high-speed superconductive electronics, and energy systems.

Prof. Berggren is one of 347 fellows elected by their peers nationwide, and among three professors at MIT to be elected this year. Read more about AAAS fellows and Prof. Berggren’s contributions here.

New Paper: “Free space-coupled superconducting nanowire single photon detectors for infrared optical communications”

This paper describes the construction of a cryostat and an optical system with a free-space coupling efficiency of 56.5% +/- 3.4% to a superconducting nanowire single-photon detector (SNSPD) for infrared quantum communication and spectrum analysis. A 1K pot decreases the base temperature to T = 1.7 K from the 2.9 K reached by the cold head cooled by a pulse-tube cryocooler. The minimum spot size coupled to the detector chip was 6.6 +/- 0.11 μm starting from a fiber source at wavelength λ = 1.55 μm. We demonstrated efficient photon counting on a detector with an 8 x 7.3 μm^2 area. We measured a dark count rate of 95 +/- 3.35 kcps and a system detection efficiency of 1.64% +/- 0.13%. We explain the key steps that are required to further improve the coupling efficiency.

Francesco Bellei, Alyssa P. Cartwright, Adam N. McCaughan, Andrew E. Dane, Faraz Najafi, Quinyuan Zhao, and Karl K. Berggren. Free space-coupled superconducting nanowire single photon detectors for infrared optical communications. ArXiv151105786 Phys. (2015). at <http://arxiv.org/abs/1511.05786>