Subwavelength phase engineering deep inside silicon
iopscience.iop.org
iopscience.iop.org
> Abstract: [...] We design and numerically demonstrate a volumetric metaoptic monolithically embedded within the bulk, achieving full 2π phase control at telecommunication wavelengths, with simulated transmission efficiencies reaching 90%. The architecture is guided by a semi-analytical Fabry–Pérot model and validated through full-wave simulations. Arrays of 250 nm-wide metaatoms spaced at 300–410 nm pitch yield a focusing efficiency of 70%. With the wafer surface left pristine, this platform can potentially enable co-integration with electronics, MEMS/NEMS, and conventional metasurfaces. Moreover, the method is directly transferable to other transparent dielectrics compatible with ultrafast laser writing. These results establish a CMOS-compatible blueprint for three-dimensional nanophotonics and multi-level integration within the wafer.