Generation of Constant Voltage Steps by a Josephson Array Driven by Optoelectronically Generated Pulses at BNM-LNE

Here we report the first results obtained at BNM-LNE on a Josephson array biased by optoelectronically generated pulse trains over repetition frequencies, f, from 0.5 to 1.75 MHz. For all the frequencies, we have observed quantized voltage steps as a function of the current pulse amplitude I_p. We demonstrate the independence of the step widths with f in close agreement with the numerical simulations and we confirm the flatness of a single voltage step