In general, the function of a passive nanophotonic device cannot be varied once its geometric and refractive index parameters are fixed. Thus, research on tunable optical nanostructures has been attracting much attention, and phasechange materials, whose optical properties can be actively controlled by thermal stimulus, have widely been utilized and integrated with nanophotonic devices. In this work, we propose a novel optimized design of an active metagrating transmission modulator composed of crossed ridge waveguides made of a VO2 film. The proposed device can provide not only near-unity modulation depth of the 0th order transmittance, but also polarization-independent operation with high efficiency and a broad bandwidth in the telecom wavelength region.
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