Quasi-Optical Josephson Oscillators

HYPRES PROPOSES A PROGRAM TO DEVELOP AND DEMONSTRATE 100 GHz TO 2,000 GHz (SUBMILLIMETER) OSCILLATORS. THESE OSCILLATORS ARE BASED ON A NOVEL IMPLEMENTATION OF THE JOSEPHSON EFFECT IN NIOBIUM SUPERCONDUCTING INTEGRATED CIRCUITS: THE QUASIOPTICAL JOSEPHSON OSCILLATOR (QJO). THE QJO WILL RADIATE COHERENTLY INTHE SUBMILLIMETER RANGE WHEN LOW VOLTAGE DC POWER IS APPLIED TO IT, JUST AS THE LASER DIODE OPERATES IN THE INFRARED AND OPTICAL RANGE. THE QJO WILL HAVE A FEW OCTAVES OF FREQUENCY TUNING AVAILABLE BY CHANGING THE DC VOLTAGE APPLIED. THE EFFORT WE PROPOSE IS IN COLLABORATION WITH PROFESSOR WENGLER OF THE UNIVERSITY OF ROCHESTER. WENGLER'S NOVEL DESIGN INVOLVES A 2-DIMENTIONAL ARRAY OF JOSEPHSON JUNCTIONS WITH THE GENERATED POWER RADIATED THROUGH DIPOLE ANTENNAS. SUBMILLIMETER SOURCES CURRENTLY AVAILABLE TEND TO BE VERY LOW POWER WITH LIMITED TUNING, OR REQUIRE KILOVOLT POWER SUPPLIES. ON THE OTHER HAND, NIOBIUM THIN FILMS AND INTEGRATED CIRCUITS BEING DEVELOPED AT HYPRES HAVE MATURED INTO A MANUFACTURABLE AND RELIABLE TECHNOLOGY, WITH RECENT DEMONTRATIONS AT HYPRES OF FLASH AND COUNTER-TYPE ANALOG-TO-DIGITAL CONVERTERS, RSFQ SHIFT REGISTERS, SUPERCONDUCTING MEMORIES, AND A VARIETY OF LOGIC GATES. HYPRES HAS EARLIER SUCCESSFULLY INTRODUCED A 70 GHz SUPERCONDUCTING DIGITIZING OSCILLOSCOPE AND TDR WHICH TO THIS DATE RETAINS THE PERFORMANCE RECORD OF ANY COMPETING INSTRUMENT. OUR GOAL IS TO DEMONSTRATE THE WENGLER QJO WITH HYPRES' NIOBIUM TECHNOLOGY, AND TO TEST A NUMBER OF PARTICULARLY PROMISING QJO DESIGNS. WE WILL COMBINE HYPRES' PROCESS EXPERTISE WITH WENGLER'S JOSEPHSON SOURCES' EXPERTISE TO PRODUCE MONOLITHIC SUBMILLIMETER WAVE OSCILLATORS OF UNPRECEDENTED EFFICIENCY, TUNABILITY, AND CONVENIENCE.