Rapid Adiabatic 3 dB Coupler with 50±1% Splitting Over 200 nm including S, C and L Bands in 45 nm CMOS Platform

We demonstrate a 70 µm-long silicon rapid adiabatic coupler (RAC) with <0.07 dB insertion loss over 50 nm and power splitting ratio 50 ± 1% over 200 nm bandwidth fabricated in the commercial 45RF ‘zero change’ CMOS electronics-photonics platform.