Impact of two-photon absorption and free-carrier effects on time lens based on four-wave mixing in silicon waveguides

摘要

We investigate the influences of two-photon absorption (TPA) and free-carrier effects on a time lens via four-wave mixing in silicon waveguides. It is found that the output waveform is severely modulated arid the conversion efficiency is sharply reduced in temporal imaging owing to the impacts of the nonlinear absorption. A silicon-organic hybrid slot waveguide with negligible TPA is proposed for the time lens, which could realize 600x magnification of femtosecond pulses. These results can increase the signal bandwidth from gigahertz to terahertz and give rise to important potential applications for ultrafast optical signal processing in integrated optics, uitrafast optics, and optical communications. (C) 2018 The Japan Society of Applied Physics