Wenfu Zhang’s research team investigated the impact of two-photon absorption (TPA) and free-carrier effects on all-optical logic gates in silicon waveguides, in which the conversion efficiency is greatly reduced and the waveform is seriously distorted. A silicon-organic hybrid dual-slot waveguide without TPA is proposed for all-optical logic gates and could offer an extremely large nonlinear parameter higher than 1.4 x 10(7) W-1 km(-1). The all-optical logic AND, OR, and XOR gates based on four-wave mixing in this waveguide are realized for 100 Gb s(-1) data signals in the C-band. These results provide potential applications for all-optical signal processing in integrated optics, optical communications, and optical computation.

（Original research article "Applied Physics Express Vol. 12, Issue 4, 042005 (2019) https://iopscience.iop.org/article/10.7567/1882-0786/ab066f"）