Observation of Quantized Voltage Steps Using a Josephson Junction Array Driven by Optoelectronically Generated Pulses. - Chiharu Urano; Nobu-hisa Kaneko; Masaaki Maezawa; Taro Itatani; Sucheta Gorwadkar; Hiroshi Saitou; J. Maeda; Shogo Kiryu (IEEE Trans. Instrum. Meas., 2007)