Ultra-broadband silicon beam-splitter based on subwavelength metamaterials

We propose an ultra-broadband and fabrication-tolerant symmetric Y–junction leveraging subwavelength metamaterials. A comprehensive experimental study over a 260 nm bandwidth (1420–1680 nm) shows TE0 excess loss below 0.3 dB. Low losses are maintained even in the presence of fabrication deviations of ±10 nm. Our power splitter also exhibits excess loss lower than 1 dB for the TE1 mode within 1475–1575 nm.