WE WILL DESIGN AND TEST A PROTOTYPE CHIP-BASED CM-SCALE METASURFACE OPTICAL ANTENNA WITH 4 PI STERADIAN ELECTRONIC BEAM STEERING CAPABILITY OPERATING IN THE C-BAND. OUR DESIGN IS BASED ON GATE-TUNABLE PLASMONIC REFLECTARRAY METASURFACES THAT ENABLE BEAM STEERING OF 1550 NM LIGHT REFLECTED FROM A TUNABLE PHASED ARRAY METASURFACE MODULATED VIA DYNAMIC ELECTRICAL CONTROL OF THE PHASE AND AMPLITUDE OF LIGHT REFLECTED FROM THE METASURFACE. TUNABILITY ARISES FROM FIELD-EFFECT MODULATION OF THE COMPLEX REFRACTIVE INDEX OF CONDUCTING OXIDE LAYERS INCORPORATED INTO REFLECTARRAY METASURFACE ANTENNA ELEMENTS EACH OF WHICH IS INDEPENDENTLY ELECTRICALLY CONTROLLED. BY MOUNTING TWO REFLECTARRAY METASURFACES IN A BACK-TO-BACK ULTRACOMPACT CONFIGURATION WE WILL ACHIEVE 4 PI STERADIAN ANGULAR RANGE VIA ELECTRONIC BEAM STEERING AT SPEEDS UP TO 10 GBPS. WE WILL ALSO EXPLORE HIGH-RESOLUTION ANGULAR BEAM STEERING CONTROL WITH METASURFACE OPTICAL ANTENNA ARRAYS THAT IS SUITABLE FOR ADDRESSING COMMUNICATIONS RECEIVERS WITHIN A SMALL FIELD-OFREGARD OF<0.3 RADIANS WITH MICRORADIAN POINTING STABILITY. ELECTRONIC BEAM CONTROL WILL ALLOW US TO POINT AND RE-POINT THE BEAM WITH A RECONFIGURATION TIME<20 MILLISECONDS. WE CAN ALSO ENABLE TIME-MODULATED TUNING WHICH WILL RESULT IN OPERATION AT MULTIPLE WAVELENGTHS MANAGING MULTIPLE-ACCESS CONTROL OVER THE C-BAND. WE WILL PERFORM THEORY AND MODELING DESIGN AND WILL DEMONSTRATE AN EXPERIMENTAL PROOF-OF-CONCEPT METASURFACE OPTICAL ANTENNA. WE WILL PERFORM TUNABLE ANTENNA ARRAY DESIGN PROTOTYPE REFLECTARRAY ANTENNA METASURFACE CHIP FABRICATION AND CHARACTERIZATION OF THE PHASE AND AMPLITUDE RESPONSE OF REFLECTARRAY ANTENNA METASURFACE CHIPS AS WELL AS TIME-RESOLVED MEASUREMENTS OF THE ANGLE AND INTENSITY OF THE STEERED FAR FIELD BEAM.