Crosstalk Suppression in Adiabatic 2x2 Couplers via Device Perturbative Reshaping

The Crosstalk Elimination via Perturbative Reshaping (CEPR) design method is introduced to ensure low modal crosstalk in adiabatic devices. It is applied to design a 2x2 coupler that experimentally achieves 50 +/- 1% split ratio and <0.1 dB loss over a 100 nm span in the O-band.