Ultra-compact multistage interferometric devices for optical communication

Densification of photonic functionality is important as the optical communication industry strives to achieve higher levels of integration. We present a new approach for folding multistage interferometric devices such that waveguide density reaches its theoretical limit. The feasibility of the approach is validated by a demonstration of a CWDM multiplexer, which was realized in a silica-on-silicon platform in a footprint of 0.18 cm
²
and exhibits state-of-the-art optical performance characteristics.