A grating structure for channeling and concentrating incident radiation
includes a regular pattern of elements each with a metallic shell
partially surrounding at least one subcavity. The subcavity is filled
with a dielectric or semiconductor. Light of one or more predetermined
wavelength ranges can be concentrated in the subcavity(s) and then
efficiently channeled through the grooves between adjacent elements. An
optoelectronic device includes the structure superposed on a substrate,
which can be semiconductive, and the elements of the grating used as
electrodes and adapted to allow a potential difference between adjacent
(electrode) elements. The optoelectronic devices include photodetectors,
e.g., metal-semiconductor-metal, pn, pin, avalanche, LEDs, IR emitting
devices, and biological or chemical sensors.