Arbitrary holographic spectral shaping of plasmonic broadband excitations

We demonstrate a new method for controlling the broadband excitations of surface plasmons. This method is based on computer-generated holographic gratings and enables not only the coupling of the broadband illumination with surface plasmons, but also the arbitrary shaping of their spectra. As an example, we demonstrate several spectral shapes numerically and measure them experimentally, finding a good agreement with the simulation results. In addition, we show the potential for shaping the plasmonic spatial profile simultaneously with its spectral profile. This method may be useful for on-chip communication and light filtering as well as for sensing and temporal manipulation of ultrashort pulses.