APPLICATION OF SURFACE-RELIEF DIFFRACTIVE OPTICS TO ACOUSTO-OPTIC SIGNAL PROCESSORS

RECENT ADVANCES IN DIFFRACTIVE (OR BINARY) OPTICS TECHNOLOGY STRONGLY SUGGEST THAT DIFFRACTIVE OPTICS MAY PROVIDE A REVOLUTIONARY SOLUTION TO THE PROBLEM OF DEVELOPING COMPACT, RUGGED OPTICAL ASSEMBLIES FOR ACOUSTO-OPTIC (AO) SIGNAL PROCESSORS. SURFACE-RELIEF DIFFRACTIVE LENSES PROVIDE THE OPTICAL DESIGNER WITH ENOUGH DEGREES OF FREEDOM TO CORRECT FOR HIGHER-ORDER ABERRATIONS. FABRICATION TECHNIQUES EXISTS TO TAILOR THE PHASE PROFILE OF EACH ZONE; THIS PROVIDES A DIFFRACTIVE LENS THAT EXHIBITS HIGH DIFFRACTION EFFICIENCY. FOR MANY CASES OF PRACTICAL INTEREST, WE HAVE SHOWN THAT A SINGLE DIFFRACTIVE LENS ACTUALLY PERFORMS BETTER THAN CONVENTIONAL LENS SYSTEMS CONSISTING OF SEVERAL AIR-SPACED GLASS ELEMENTS. THE PRIMARY OBJECTIVE OF THE PROPOSED RESEARCH IS TO DEMONSTRATE THE FEASIBILITY OF UTILIZING DIFFRACTIVE OPTICS TECHNOLOGY TO ANSWER PERFORMANCE CONSTRAINTS IN COMPACT SPECTRUM ANALYZERS AND MINIBENCH TIME-INTEGRATING CORRELATORS. WE PROPOSE TO IDENTIFY INNOVATIVE DESIGNS THAT EMPLOY A MINIMUM OF OPTICAL ELEMENTS WITHOUT SACRIFICING PERFORMANCE OR LIGHT EFFICIENCY WHILE MAINTAINING MECHANICAL STABILITY. A SIGNICICANT PORTION OF THE RESEARCH WILL BE TO HELP ENHANCE EXISTING PROCESSOR PERFORMANCE THROUGH THE USE OF COMBINATIONS OF DIFFRACTIVE AND CONVENTIONAL COMPONENTS IN CURRENT DESIGNS. WE ALSO PLAN TO INVESTIGATE NOVEL USES OF DIFFRACTIVE OPTICS IN DESIGNS FOR NEXTGENERATION SYSTEMS. THE MANUFACTURABILITY OF THE DIFFRACTIVE COMPONENTS WILL BE STUDIED. A FIRST-ORDER TOLERANCE ANALYSIS WILL BE UNDERTAKEN FOR THE MOST PROMISING DESIGNS. WE ALSO PLAN TO HELP DEFINE IMPORTANT ENVIRONMENTAL REQUIREMENTS INCLUDING STABLE MATERIALS AND RUGGED MECHANICAL MOUNTING TECHNIQUES. PHASE II RESEARCH AND DEVELOPMENT WILL CONCENTRATE ON FABRICATING PROTOTYPES OF A DESIGN USEFUL TO THE ARMY. IT IS EXPECTED THAT THE PHASE II DEVELOPMENT WILL LEAD TO SIGNIFICANTLY ENHANCE PROTOTYPE SYSTEMS.