Blanco-Redondo A, Husko C, Eades D, Zhang Y, Li J, Krauss T F, Eggleton B J
1] Centre for Ultrahigh bandwidth Devices for Optical Systems (CUDOS), Institute of Photonics and Optical Science (IPOS), School of Physics, The University of Sydney, Sydney, New South Wales 2006, Australia [2] ICT-European Software Institute Division, Tecnalia, Parque Tecnologico de Bizkaia, Ibaizabal Bidea, Edificio 202, Zamudio, Bizkaia E-48170, Spain [3].
1] Centre for Ultrahigh bandwidth Devices for Optical Systems (CUDOS), Institute of Photonics and Optical Science (IPOS), School of Physics, The University of Sydney, Sydney, New South Wales 2006, Australia [2].
Nat Commun. 2014;5:3160. doi: 10.1038/ncomms4160.
Solitons are nonlinear waves present in diverse physical systems including plasmas, water surfaces and optics. In silicon, the presence of two photon absorption and accompanying free carriers strongly perturb the canonical dynamics of optical solitons. Here we report the first experimental demonstration of soliton-effect pulse compression of picosecond pulses in silicon, despite two photon absorption and free carriers. Here we achieve compression of 3.7 ps pulses to 1.6 ps with <10 pJ energy. We demonstrate a ~1-ps free-carrier-induced pulse acceleration and show that picosecond input pulses are critical to these observations. These experiments are enabled by a dispersion-engineered slow-light photonic crystal waveguide and an ultra-sensitive frequency-resolved electrical gating technique to detect the ultralow energies in the nanostructured device. Strong agreement with a nonlinear Schrödinger model confirms the measurements. These results further our understanding of nonlinear waves in silicon and open the way to soliton-based functionalities in complementary metal-oxide-semiconductor-compatible platforms.
孤子是存在于包括等离子体、水面和光学等多种物理系统中的非线性波。在硅中，双光子吸收以及伴随的自由载流子的存在会强烈干扰光学孤子的规范动力学。在此，我们报道了尽管存在双光子吸收和自由载流子，但首次在硅中实现皮秒脉冲的孤子效应脉冲压缩的实验演示。在此，我们将3.7皮秒的脉冲压缩至1.6皮秒，能量小于10皮焦。我们展示了约1皮秒的自由载流子诱导的脉冲加速，并表明皮秒输入脉冲对这些观测结果至关重要。这些实验通过色散工程慢光光子晶体波导和超灵敏频率分辨电门控技术得以实现，该技术用于检测纳米结构器件中的超低能量。与非线性薛定谔模型的高度吻合证实了测量结果。这些结果加深了我们对硅中非线性波的理解，并为互补金属氧化物半导体兼容平台中基于孤子的功能开辟了道路。
