Fabrication-tolerant Y-junction for high-performance power division using subwavelength silicon metamaterials

We propose a high-performance and fabrication-tolerant beamsplitter based on a Y–junction engineered through subwavelength silicon metamaterials. The fabricated proof-of-concept device yields experimental excess loss below 0.2 dB for the fundamental transverse-electric mode in a 195 nm bandwidth for a fabrication resolution of 50 nm.