Fluorescence detection is widely used in biology and medicine, while the realization of on-chip fluorescence detection is vital for the portable and point-of-care test (POCT) application. In this Letter, we propose an efficient fluorescence excitation and collection system using an integrated GaN chip consisting of a slot waveguide and a one-dimensional photonic crystal (1D PC) waveguide. The slot waveguide is used to confine the excitation light for intense light–sample interaction, and the one-trip collection efficiency at the end of slot waveguide is up to 14.65%. More interestingly, due to the introduction of the 1D PC waveguide, the fluorescence signal is directly filtered out, and the excitation light is reflected to the slot waveguide for multiple excitations. Its transmittances for the designed exciting wavelength of 520 nm and the fluorescent wavelength of 612 nm are 0.2% and 85.4%, respectively. Finally, based on numerical analysis, the total fluorescence collection efficiency in our system amounts to 15.93%. It is the first time, to our knowledge, that the concept of an all-in-one-chip fluorescence detection system has been proposed, which paves the way for on-chip fluorescence excitation and collection, and may find potential applications of miniaturized and portable devices for biomedical fluorescence detection.

利用非线性效应的全矢量模型和狭缝波导的有限元模场求解法，系统地研究了狭缝波导结构和包层材料对其非线性和功率限制特性的影响.研究结果表明，狭缝波导的硅臂宽度、狭缝宽度、硅层高度和包层材料均影响其非线性和功率限制特性.对于空气包层狭缝波导，不同结构参数下的最高功率限制因子对应的非线性系数均高于20 W^-1·m^-1，而最低非线性系数6.5 W^-1·m^-1均出现在模式截止附近，泄露损耗较大，功率限制较弱，故空气包层狭缝波导无法同时实现低非线性和高功率限制；如果在狭缝波导上包覆二氧化硅，则可以同时获得低非线性和高功率限制，非线性系数可低至4.12 W^-1·m^-1，同时功率限制因子可达42%.

设计了在极近红外波段（890 nm）的聚合物基狭缝波导微环折射率传感器.分析了波导高度、宽度及狭缝宽度对灵敏度的影响，以找到最佳的设计标准用于折射率传感.采用电子束光刻工艺制备了硅母版模，并用独特的氟化聚合物PFPE从硅母版模上成功制备了柔性软模具.采用紫外软压印工艺制备了聚合物基狭缝波导.波导的宽度和高度以及狭缝波导的宽度分别约为510 nm、830 nm和234 nm，聚合物狭缝波导残留层的厚度约为350 nm.制备的狭缝波导具有高的高宽比并与低成本批量生产工艺相兼容.