Multiphase resonant properties in metallic dielectric gratings with three-slits

The optical transmission properties in a three-slit metal grating with different mediums are studied. The results show that the tunable phase resonances and multiple phase resonances can be obtained by filling different mediums into the three slits of the straight channel grating. When the medium in the three slits is extremely asymmetric, the phenomenon of multiphase splitting becomes very obvious. In addition, based on the field distributions, multiphase resonant mechanisms have been proposed for the physical origins of the observations. In addition, a multi-channel selector is described by flexibly controlling the light through any slit of the grating. Compared with the conventional compound grating, this grating with different mediums has obvious advantages, such as simple structure, and ease of implementation.