SUPERCONDUCTING TERAHERTZ DETECTORS AND GENERATORS

THIS PHASE I PROGRAM IS INTENDED TO DEMONSTRATE EXPERIMENTALLY AND THEORETICALLY THE TECHNICAL FEASIBILITY OF BUILDING HIGH-FREQUENCY GENERATORS AND RECEIVERS FROM THE HIGH TEMPERATURE SUPERCONDUCTORS SUCH AS YBA(2)CU(3)O(7). THE EXPERIMENTAL METHOD PROPOSED IS TO CONSTRUCT ORIENTED THIN FILMS OF THE MATERIAL BY VACUUM VAPOR DEPOSITION OF THE ELEMENTS IN THE PRESCRIBED RATIOS UPON AN APPROPRIATE SUBSTRATE, AND TO STUDY THE CURRENT-VOLTAGE CHARACTERISTICS AT HIGH FREQUENCIES. THE FILMS WILL BE PREPARED IN VARIOUS GEOMETRIES: (1) UPON A FLAT SUBSTRATE SURFACE FOR THE INVESTIGATION OF THE CURRENTVOLTAGE CHARACTERISTICS INTRINSIC TO THESE MATERIALS, AND (2) ENCLOSING SMALL (LESS THAN 1 MM(2) IN CROSS-SECTION) SOLID CRYSTALS OF THE SUBSTRATE CUT INTO VARIOUS GEOMETRIES, SO AS TO FORM A CAVITY SUITABLE FOR DETECTION AND GENERATION AT FREQUENCIES APPROACHING TERAHERTZ. IN ADDITION, THEORETICAL CALCULATIONS OF THE FEASIBILITY OF OBTAINING HIGH-FREQUENCY COHERENT JOSEPHSON RADIATION, AND THE ELECTROMAGNETIC RESPONSE OF A CAVITY ENCLOSED BY AN ANISOTROPIC SUPERCONDUCTOR WILL BE PERFORMED, WITH THE GOAL OF AIDING IN THE EXPERIMENTAL DESIGN.