Department of Applied Physics;
Stanford University;
Stanford;
CA 94305;
USA;
National Laboratory of Solid State Microstructures;
School of Electronic Science and Engineering and Collaborative Innovation Center of Advanced Microstructures;
Nanjing University;
Nanjing 210093;
China;
Department of Materials Science and Engineering;
Massachusetts Institute of Technology;
MA 02139;
USA;
Department of Electrical and Computer Engineering;
University of Wisconsin-Madison;
Madison;
WI 53706;
USA;
Department of Electrical Engineering;
Ginzton Laboratory;
Stanford University;
Stanford;
CA 94305;
USA;
angle-selective perfect absorption; angle-selective thin optical element; graphene; mid-infrared; two-dimensional materials;