2D wavelength-polarization dispersive microspectroscope based on a hybrid plasmonic helical nanostructure

Abstract: Microspectrometer features remarkable portability and integration, and is prospected to provide quick detection tools to daily life and revolutionary techniques to researchers. For the extremely finite footprint, microspectrometer can hardly work to analyze the polarization feature by placing polarizer in the optical path like conventional spectrometers. Here, we demonstrate a novel 2D wavelength-polarization dispersive microspectroscope based on carbon nanocoil with plasmonic Au nanopariticles (Au/CNC) as a dispersive component. Explored by the microspectrum and Fourier-space microscopy, a unique 2D dispersive characteristic of the Au/CNC is revealed. Along the axis of the coil, Au/CNC disperses light as wavelength to bands of different diffraction orders like a grating. Wavelength of the incident light can be obtained from the position of the signal lines in a quite large visible-near-infrared wavelength range with an acceptable resolution. In the direction perpendicular to the axis of the coil, incident light is dispersed as polarization with bright and dark areas. We can distinguish left- and right-circularly-polarized light, and also obtain the polarization orientation of linearly-polarized light. Based on this effect, a wonderful 2D wavelength-polarization microspectrometer can be built. It not only fulfills the wavelength analysis with a tiny dispersive component, but also simultaneously knows the polarization feature of the incident light in one shot. Moreover, this powerful tool can further evolve new revolutionary techniques via integrated with other systems.