We demonstrate wide-angle, broadband and efficient reflection holography by utilizing coupled dipolepatch nano-antenna cells to impose an arbitrary phase profile on of the reflected light. High fidelity images were projected at angles of 45 0 and 20 0 with respect to the impinging light with efficiencies ranging between 40%-50% over an optical bandwidth exceeding 180nm. Excellent agreement with the theoretical predictions was found at a wide spectral range. The demonstration of such reflectarrays opens new avenues towards expanding the limits of large angle holography.

Abstract-Uniplanar compact electromagnetic bandgap (UC-EBG) substrate has been proven to be an effective measure to reduce surface wave excitation in printed antenna geometries. This paper investigates the performance of a microstrip antenna phased array embedded in an UC-EBG substrate. The results show a reduction in mutual coupling between elements and provide a possible solution to the "blind spots" problem in phased array applications with printed elements. A novel and efficient UC-EBG array configuration is proposed. A probe fed patch antenna phased array of 7 5 elements on a high dielectric constant substrate was designed, built and tested. Simulation and measurement results show improvement in the active return loss and active pattern of the array center element. The tradeoffs used to obtain optimum performance are discussed.Index Terms-Electromagnetic bandgap (EBG), microstrip antenna phased array, mutual coupling, uniplanar compact electromagnetic bandgap (UC-EBG) geometry.

We introduce an ultrasensitive detection technique for refractive index (RI) sensing based on an array of nanometer scale slot-antennas milled in a thin gold layer using a single lithographic step. Our experimental figures of merit (FOMs) of 140-210 in the telecom wavelength range approach the fundamental limit for standard propagating SPR sensors (~250).The underlying mechanism enabling this is the combination of a narrowband resonance of the slot-antennas with degeneracy breaking of Wood's anomaly under slightly non-perpendicular illumination. In addition, we explore the sensitivity of the device to the depth of the analyte layer. This concept can be easily tuned to any desired wavelength and RI range by modifying the slot dimensions and the array spacing, thus rendering it highly useful for numerous sensing applications.

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