非线性光学频率转换，例如倍频等现象在微纳光学器件中已获得广泛研究，将来亦有可能作为一种重要的微纳光源得到应用。然而，在微纳尺度上对非线性光波进行偏振、相位、强度的调控，是提高非线性微纳光源的性能的重要因素。如何有效地调控微纳光学元件上的非线性光场过程是制约微纳光学器件走向实际应用的“瓶颈”问题之一。.在此背景下，本项目拟利用具有高非线性系数的功能介质（有机半导体薄膜），研究基于金属-介质的复合光学超构表面。通过电致倍频效应、非线性贝里几何相位等物理原理，研发新型的非线性超构表面器件，实现对倍频光的振幅、相位、偏振等参数进行多维度调控。本项目的成功可为设计新型的非线性微纳光源奠定重要理论与技术基础。

Nonlinear frequency conversion, such as second harmonic generation (SHG) and other phenomena, have been widely explored in nanophotonic devices, because of its great potential in designing light sources at the micro/nanoscale. However, controlling over the polarization, phase and intensity of the nonlinear waves is the key issue for improving the performance of nonlinear light sources with micro/nanoscale size. How to effectively tune the nonlinear optical fields in the nanophotonic device will be one of the bottlenecks that limit its practical application..Under this research background, our project proposes to study metal-dielectric hybrid optical metasurface by using the dielectric materials (organic semiconducting films) with high nonlinear optical coefficients. Based on the principles of electric field induced second harmonic generation(EFISH), as well as the theory of nonlinear geometric Berry phase, we should be able to develop novel nonlinear metasurface devices that allow effective and multi-dimensional control of the amplitude, phase and polarization of SHG waves. The successful implementation of this project will lay a solid foundation, both theoretically and technologically, for the design of novel nonlinear optical sources with micro/nanoscle size.