10 th International Congress on Advanced Electromagnetic Materials in Microwaves and Optics – Metamaterials 2016 Crete, Greece, 17-22 September 2016 Metasurface-enabled Pyroelectric Detection of 140 GHz Radiation with Strong Polarization Discrimination S. A. Kuznetsov 1,2,3 , M. Navarro-Cía 4,5 , A. G. Paulish 3 , A. V. Arzhanikov 1,2 1 Novosibirsk State University, Pirogova St. 2, Novosibirsk, 630090, Russian Federation 2 Budker Institute of Nuclear Physics SB RAS, Lavrentiev Ave. 11, Novosibirsk, 630090, Russian Federation 3 Institute of Semiconductor Physics SB RAS, Novosibirsk Branch “TDIAM”, Lavrentiev Ave. 2/1, Novosibirsk, 630090, Russian Federation 4 School of Physics and Astronomy, University of Birmingham, Birmingham B15 2TT, UK 5 Optical and Semiconductor Devices Group, Department of Electrical and Electronic Engineering, Imperial College London, London SW7 2BT, UK. m.navarro-cia@bham.ac.uk Abstract – Despite the potential of the millimeter- and submillimeter-wave region for fundamental science and industrial applications, its technology is well behind microwaves and optics in terms of performance and cost. We propose to improve a millimeter-wave technology by engineering cost effective solutions from neighboring spectral regions. Specifically, a pyroelectric infrared sensor is transformed into a polarization-selective millimeter-wave detector of 140 GHz radiation by integrating to it a metasurface absorber, which is 136 times as thin as the operating wavelength λ and has the overall dimensions near λ. It is demonstrated that, due to the small thickness and hence the thermal capacity of the absorber, the novel detector keeps high values of the response speed and sensitivity to polarized mm- wave radiation changed insignificantly against the regime of IR detection. I. INTRODUCTION Engineering the microscopic structure of artificial materials and surfaces to manipulate macroscopically electromagnetic waves is a powerful idea championed by the metamaterial community [1], [2]. After great deal of effort on its fundamentals, this philosophy has triggered the interest to develop technology, especially at radiofrequency and microwaves where fabrication is less stringent than at higher frequencies. In addition, the focus has been reoriented toward metasurfaces, the two-dimensional equivalent of metamaterials, given their easier manufacture and integration [3]. At the top end of microwaves, the so-called millimeter-wave regime, low-cost devices are hardly found commercially [4] given the difficulty to find suitable inexpensive materials and to fabricate with micrometer precision centimeter size samples. A possible solution that we propose to overcome this problem is to extend the range of infrared devices with the help of metasurfaces. To illustrate our approach, an off-the-shelf pyroelectric infrared detector insensitive to millimeter-wave radiation is converted into a highly selective 140 GHz (millimeter-wave) polarization dependent detector by simply covering the top electrode with an ultrathin metasurface-based absorber [5]. A remarkable finding from the tested prototypes is that the detector keeps its high performance at millimeter waves despite the fact the absorbing area is restricted to the original package size having λ × λ dimensions. We conclude that this is a consequence of the strong metasurface-ground plane capacitive coupling inherent for the deep-subwavelength- thinness regime. II. ABSORBER: DESIGN CRITERIA AND RESULTS In pyroelectric sensors, a temporary voltage signal is generated by a pyroelectric film as a result of a its temperature change due to radiation absorption. To maximize the absorption of millimeter waves, we designed an ultrathin three-layer absorber composed of a metasurface on top of a grounded dielectric slab. Several types of metasurfaces are considered, but our analysis distinguished a simple array of rectangular patches to attain the required performance and polarization discrimination. In particular, the advantage of the “patch array” absorber