Antenna coupled Kinetic Inductance arrays for space and ground based imaging arrays

Abstract

Very large arrays of Microwave Kinetic Inductance Detectors (MKIDs) have the potential to revolutionize ground and space based astronomy. They can offer in excess of 10000 pixels with large dynamic range and very high sensitivity in combination with very efficient frequency division multiplexing at GHz frequencies. In this paper we present the development for a ∼100 pixel MKID demonstration array based upon an single pixel consisting of an integrated MKID‐antenna detector, with the antenna placed in the second focus of an elliptical Si lens. The design presented can be scaled to any frequency between 80 GHz and >5 THz because there is no need for superconducting structures that become lossy at frequencies above the gap frequency of the materials used. We present measurements of the optical coupling efficiency, sensitivity and discuss array development. We have obtained a dark sensitivity of 7×10−19W/Hz1/2 using 100 nm thick A1 devices and an optical coupling efficiency of 35% referring to the power of a single polarization optical signal in front of the Si lens of the detector.