Nonlinear photonics in silicon-on-insulator nanostructures

硅基纳米光子学正在成为高效全光信息处理竞赛中的一个重要竞争者，同时也正在成为基础研究的一个迷人的舞台。将光学器件集成到微电子芯片中，现在不仅是学术研究人员讨论的问题，而且也包括在英特尔和IBM等微电子巨头的商业计划中。片上纳米光子学最早的实际应用之一可能是对多频数据流进行紧凑的光学处理。纳米硅波导(光子线)和谐振器提供了一种在芯片上实现光子组件的非常有吸引力的方式。这是因为硅和空气之间的折射率对比度很大，因此1550 nm波长的光可以被严格限制在500 nm的波导宽度内。另一个广为人知的优势是有可能使用成熟和广泛的互补金属氧化物半导体(Cmos)技术。硅纳米结构中显著的超快克尔非线性的存在潜在地允许器件以不久的将来高性能子系统所需的太赫兹速率运行。非线性和色散控制是开发调制器、开关、延迟线和放大器等全光处理器件所需的关键特性。如果我们要理解和探索这些结构中的基本光学物理，它们也是需要控制的关键参数。色散和非线性之间的相互作用导致了孤子的形成和调制不稳定性，这将是时间控制和频谱调整所必需的。光孤子社区的梦想之一是由非线性材料制成的三维光子芯片，其中所有的路由都是通过空间孤子完成的，然后空间孤子充当一个可立即重新配置的灵活的波导网，通过时间孤子传输和处理数据。这里提出的平面硅片中的孤子效应可能是我们所能期望的最接近这个梦想的结果。该研究方案的总体目标是：制作一系列用于观察时空孤子、频率转换以及飞秒脉冲的光谱、时间和空间整形的绝缘体上硅结构；研究腔阵列中的双稳效应；通过实验观察和模拟上述效应，加深对它们的物理理解；利用硅的独特性质观察新的光学现象；确保在非线性纳米光子学领域取得进一步的科学进展。

Silicon based nano-photonics is becoming a prominent contender in the race for effective all-optical information processing - and is simultaneously becoming a fascinating arena for fundamental research. Integration of optical devices into microelectronic chips is now not only discussed by academic researchers, but is also included in the business plans of microelectronics giants such as Intel and IBM. One of the first practical applications of on-chip nanophotonics is likely to be compact optical processing of multifrequency data streams. Nano-sized silicon waveguides (photonic wires) and resonators offer a very attractive way of realizing photonic components on a chip. This is due to the large index contrast between silicon and air, so that light at a wavelength of 1550nm can be tightly confined for waveguide widths as small as 500 nm. Another widely-recorgnised advantage is the possibility of using well established and wide-spread complementary metal-oxide-semiconductor (CMOS) technology. The presence of a substantial ultrafast Kerr nonlinearity in Silicon nano-structures potentially allows devices to perform at the THz rates that will be required in near-future high-performance sub-systems. Nonlinearity and dispersion control are the key properties needed to develop all-optical processing devices such as modulators, switches, delay lines and amplifiers. They are also the key parameters to be controlled if we are to understand and explore the fundamental optical physics in these structures. The interplay between dispersion and nonlinearity leads to such effects as soliton formation and modulation instability, which will be essential for temporal control and spectral modification. One of the dreams of the optical soliton community has been a three dimensional photonic chip made of a nonlinear material where all the routing is done by means of the spatial solitons, which then serve as an instantly reconfigurable and flexible network of waveguides for transmission and processing of data by means of temporal solitons. The soliton effects in planar silicon chips proposed here are possibly as close as we can hope to get to this dream. The overall aims of the research programme are: to fabricate a range of silicon-on-insulator structures for observation of spatiotemporal solitons, frequency conversion, and spectral, temporal and spatial shaping of femtosecond pulses;bistability effects in cavity arrays; experimentally observe and model the above effects, develop their physical understanding; use the unique properties of silicon to observe new optical phenomena; ensure further scientific progress in the area of nonlinear nano-photonics.