▎ 摘　　要

Midinfrared spectrum region has proved its great potential in various fields including security, medical examination, product inspection, and materials characterization. However, midinfrared detectors, one of the most important components, have not been fully developed and their performance can be much improved. In contrast to well-known nanostructured semiconductor detectors, graphene-based detectors are emerging and are proposed to tackle shortcomings of earlier detectors. Nevertheless, they still suffer from obstacles due to low light absorption originating from a single atomic layer. Recently, the introduction of plasmonic antennas is changing the situation and is attracting much interest. We present a midinfrared photodetector based on a multiresonant frequency bull's eye antenna coupled with monolayer graphene. The bull's eye antenna is one of the plasmonic antennas that can achieve high concentration of electric field and enhanced transmission of incident light. Though conventional bull's eye antennas exhibit only single resonant frequency that restricts to a measured frequency range, we here designed and fabricated the bull's eye antenna with wider band transmission so that various frequency regions can be studied with a single device. We demonstrated that the graphene device integrated with the multifrequency plasmonic antenna enabled the room-temperature midinfrared detection, together with the ability of frequency filtering in a desirable band. Our device design is also applicable to other frequency regions including visible light and terahertz waves by adjusting structural parameters. (C) 2018 Society of Photo-Optical Instrumentation Engineers (SPIE)