Nanooptics

We present two-dimensional plasmonic Doppler grating (PDG) for broadband azimuthal angle-resolved nanophotonic applications. The PDG consists of a set of non-concentric circular rings mimicking the wavefronts of a moving point source that exhibits Doppler Effect and thereby offers continuous azimuthal angle-dependent lattice momentum for photon-plasmon coupling. The center and span of the working frequency window is fully designable for optimal performance in specific applications. We detail the design , fabrication and optical characterization of the PDG. The design of Dopplergrating provides a general platform for in-plane angle-resolved nanophotonic applications.