An optoelectronic pulse drive for quantum voltage synthesizer

Abstract

An optoelectronic pulse drive system based on commercially available telecoms optoelectronic components and a field-programmable gate array has been developed. In order to allow the use of ac-coupled optoelectronic components, a method of adding and subtracting complementary pulses was developed. The system was used to drive a Josephson junction array to synthesize quantum-Accurate voltage waveforms. These waveforms will be used in voltage waveform metrology applications. Results from the synthesis of sinusoidal unipolar voltage waveforms from 3 to 300 kHz are presented. The margin of operation was measured and shown to require an optical pulse height stability better than 0.15 mW. The use of delta-sigma code with repeated sections, suitable for a quantum voltage digitizer was also examined. A test code corresponding to a delta-sigma feedback loop rate of 250 MHz was used to synthesize a 3.125 kHz sinusoidal waveform.