We report the experimental realization of a multifunctional microscale plasmonic metasurface capable of sampling a light beam and performing five functionalities, while allowing high direct transmission and maintenance of the properties of the input light beam. The plasmonic metasurface integrates light-to-surface-plasmon coupling, two-channel wavelength demultiplexing with a channel spacing smaller than 44 nm, wavelength and polarization controllable beam splitting of a monochromatic, single polarization signal, and four-level polarization and wavelength-polarization demultiplexing in an all-in-one structure. Such a device can play a key role for on-chip adaptable integrated circuits for parallel signal processing, communications, and nondestructive sensing.
