Graphene-Based Antenna Coupled Terahertz Detector

Graphene-based optoelectronic devices has drawn great interest due to its atractive electromagnetic, mechanical, electrical, and thermal properties. Unlike semiconductors graphene has no band gap, therefore can absorb photons from a wide frequency bandwidth efficiently by impedance matching. In graphene photon energy can increase its temperature significantly and due to the very stiff carbon lattice the electron-phonon interaction is weak, making cooling contribution by phonon emission very small. All these characteristics make graphene a good candidate for thermal based photon detectors. Antennas are elements that can be used either to receive or to transmit electromagnetic waves, when used in reception mode electromagnetic waves induce currents in the antenna elements that can be later detected and used for various applications. Antennas have several unique advantages such as polarization sensitivity, directivity, small footprint, tunability and the possibility of integration into electronic and photonic circuits. Antennas have been coupled to thermal detectors, such as bolometers, to increase its frequency response and incorporate some desirable characteristics of the antenna into the antenna-coupled detector, such as a specific bandwidth or polarization dependence. In this work different types of antennas coupled to graphene nanostructures will be evaluated numerically using COMSOL Multiphysics. Results will show the bandwidth, polarization dependence and responsivity of square-spiral, log-periodic and Archymedean spiral antennas coupled to graphene nanostructures, and the advantages of using each one of those antennas in terahertz detection applications.