Demonstration of an Integrated Photonic Magic T – a Robust Beam Splitter and Novel Polarization Diversity Building Block

We demonstrate an adiabatic magic T in a 45 nm CMOS photonics foundry platform, with 3±0.25 dB power splitting and <1.2 dB loss over 1530-1600 nm, with a 60 µm-long device. It functions as a 2×2 beam splitter with splitting ratio from both input ports fundamentally robust by symmetry, and supports novel polarization diversity and modulator designs.