Nanophotonic devices and nanostructured materials for enhanced nonlinear optical interactions and optical signal processing

由于有限的带宽，现代光通信网络受到电子信号处理的根本限制。为了克服这些限制，全光信号处理是必要的，因为光学材料显示出比电子信号处理中可用的更宽的带宽。全光信号处理完全依赖于光与物质的非线性光学相互作用。这种相互作用导致新的光谱分量的出现和支持光束传播的介质的光学响应的修改。信息流的光谱中新频率的出现对于用于将信息信道从一个频带传输到另一个频带的波长转换是至关重要的。对于在物理上分离的通道之间的信息流的光学交换来说，通过非线性相互作用来修改光学介质的响应是必要的；它几乎可以立即发生，比电交换快得多。 另一个可以从非线性光学相互作用中受益的目标领域是量子信息。在量子通信网络中，人们可以安全地编码和传输信息。量子信息完全依赖于相关(纠缠)光子对的产生。这种光子对可以通过非线性光学相互作用产生，将一束光束分解(下转换)为具有新频率的两束光束。 提出的研究计划的目标是开发纳米光电子器件和纳米结构材料，旨在为光通信网络中的全光信号处理和量子信息领域产生高效的非线性光学相互作用。为了实现光子材料和器件的非线性光学响应的增强，将寻求几种方法。第一种方法包括设计集成光学器件和光子纳米结构，以产生所需的增强。第二种方法是以材料为基础的；它依赖于纳米复合光学材料的非线性光学响应的物理学，这些材料是两种或两种以上均质组分的纳米级混合物。在这种材料中，单个颗粒的尺寸远远小于光的波长，通过适当的剪裁，可以在光学非线性较高的组件中实现具有局域化的静电光场重新分布。这两种方法的结合有望导致光学非线性的显著增强，为新的有趣的物理和实际应用开辟道路。在用于全光信号处理的集成光学元件中实现增强的非线性光学响应，以及在制造集成量子光学网络中实现增强的非线性光学响应是拟议研究计划的最终目标。

Modern optical communication networks suffer from fundamental limitations of electronic signal processing due to the limited bandwidth. All-optical signal processing is necessary to overcome these limitations, as optical materials exhibit much broader bandwidth compared to that available in electronic signal processing. All-optical signal processing relies fully on nonlinear optical interactions of light with matter. Such interactions result in the appearance of new spectral components and the modifications of the optical response of the medium supporting the propagation of the optical beams. The appearance of new frequencies in the optical spectrum of the information streams is crucial for wavelength conversion used for transferring the information channels from one frequency band to another. The modifications of the optical media’s response by nonlinear interactions are necessary for optical switching of the information streams between physically separated channels; it can occur nearly instantly, much faster than electrical switching. Another target area that can benefit from nonlinear optical interactions is quantum information. In quantum communication networks, one can securely encode and transmit information. Quantum information fully relies on generation of correlated (entangled) photon pairs. Such photon pairs can be produced through nonlinear optical interactions, decomposing (down-converting) an optical beam into two beams with new frequencies. The goal of the proposed research program is to develop nanophotonic devices and nanostructured materials aimed at producing highly efficient nonlinear optical interactions for all-optical signal processing in optical communication networks, and for the field of quantum information. Several approaches will be pursued towards the realization of enhancement in nonlinear optical response of photonic materials and devices. The first approach includes engineering integrated optical devices and photonic nanostructures to produce the desired enhancement. The second approach is material-based; it relies on the physics of the nonlinear optical response of nanocomposite optical materials which are nanoscale mixtures of two or more homogeneous constituents. The size of individual grains in such materials is much smaller than the wavelength of light, and the electrostatic optical field redistribution with the localization in the component with the higher optical nonlinearity can be achieved by a proper tailoring. Combining the two approaches is expected to result in dramatic enhancements of the optical nonlinearity, opening up the route to new interesting physics and practical applications. The implementation of the enhanced nonlinear optical response in integrated optical components for all-optical signal processing, as well as in producing integrated quantum optics networks is an ultimate goal of the proposed research program.