Applied Physics Letters

Optoelectronic generation and detection of single-flux-quantum pulses

Chia-Chi Wang, Marc Currie, D. Jacobs-Perkins, M. J. Feldman, Roman Sobolewski, Thomas Y. Hsiang

Published Jun 12, 1995• 34 citations

Abstract

We report on the direct observation of a single-flux-quantum (SFQ) pulse. The response of a metal–semiconductor–metal photodiode to a femtosecond laser pulse was used to switch Josephson junctions and to generate an SFQ voltage pulse on a superconducting microstrip line. The detailed shape of the pulse was measured optoelectronically, using a cryogenic electro-optic sampling system. The measured SFQ pulse had a width of 3.2 ps, an amplitude of 0.67 mV, and a total pulse content of 2.1±0.2 mV×ps, corresponding to the quantum of magnetic flux h/2e. With larger excitation, multiple SFQ pulses were observed. Numerical simulations are shown to be qualitatively similar to our experimental results.

DOI: 10.1063/1.113745

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