An optically coupled superconducting analog to digital converter

A superconducting analog-to-digital converter has been coupled with a laser diode also operating at 4.2 K to provide a serial output data stream via an optical fiber. The optical signal is converted to a room temperature electrical signal using standard optical fiber receiver techniques. After amplification these signals are fed into a fast comparator circuit. The output of the comparator is a TTL level signal suitable for connection to conventional electronic equipment.