Hybrid plasmonic-dielectric resonant waveguide grating for wavelength-selective diffraction

The search for full control of amplitude and phase of the electromagnetic field from planar surfaces is of high interest for the development of highly integrated photonic systems and flat optical devices. A hybrid dielectric-plasmonic resonant waveguide grating which enables highly wavelength-selective first order diffraction in a multimode light guide is reported. Measurements show a narrowband peak in the first order of diffraction at resonance, while the undesired transmitted signal is strongly suppressed at other wavelengths as well as in the zeroth diffraction order. Another hybrid resonant waveguide grating is reported and shows a bandwidth of 20nm in the zeroth order of transmission. Overall, this work shows the promising use of hybrid structures for taking the best features of both plasmonic and dielectric grating resonances for designing highly integrated optical devices such as spectrometers or optical security features.