阵列波导光栅应用于微型拉曼光谱仪分光芯片的研究

Using the new developed shell-isolated nanoparticle-enhanced Raman spectroscopy (SHINERS) technology (Z. Tian, Nature, 2010, 464, 18, p392), different chemicals can be identified simultaneously with high sensitivity in a few seconds. Accordingly, SHINERS is believed to be a strong detection tool in the area of food safety. However, it is hard to expand its scope of applications due to nowadays expensive, bulky Raman spectrometer. In this proposal, An novel arrayed waveguide grating (AWG) dispersive chip is proposed to replace the traditional gratings and lenses optical system, and to reduce the volume and price of a Raman spectrometer to more than one order of magnitude. Micro Raman spectrometer based on this chip and SHINERS technology will promote the detection ability of harmful chemicals in food significantly in an affordable and portable way. Through the analysis of the technical requirements of micro Raman spectrometer on AWG dispersive chip, a novel AWG design is proposed. Here a cascade AWGs structure is used to realize a broad wavelength range, and each AWG in this cascade structure has high diffraction orders waveguide array with equivalent curvature to reduce the insertion loss. Theoretically model, simulation optimization and fabrication process of this novel AWG chip will be developed in this project. As the results, the design theory and optimization algorithm of this AWG dispersive chip will be achieved, and a novel optical dispersive chip will be fabricated.

厦门大学田中群教授2010年在Nature发表的壳层隔绝纳米粒子增强拉曼（SHINERS）技术能够同时实现多种化学成分的高灵敏度检测，在食品安全领域具有独特的优势，但目前昂贵、笨重的拉曼光谱仪器严重阻碍了其应用范围的进一步扩大。利用阵列波导光栅（AWG）的原理研制色散芯片取代原来的光栅、透镜组成的光学系统，将会使拉曼光谱仪器的体积和价格下降一个数量级以上，在检测仪器和方法方面，将对缓解我国目前严峻的食品安全形势具有重大意义。本课题针对微型拉曼光谱仪对阵列波导光栅的技术要求，即宽工作波长范围和低损耗的要求，创新性地提出了采用级联技术展宽波长范围，采用高衍射级次，等曲率阵列波导结构降低插入损耗的方法，针对性地开展理论建模、仿真优化和工艺研制研究，最终在理论上获得拉曼光谱仪专用的AWG色散芯片的设计理论和优化算法，在应用上结合SHINERS技术，研制出微型拉曼光谱仪迫切需求的新型分光芯。

如今，拉曼光谱技术在食品安全、环境监测等领域获得了广泛的应用，但目前昂贵、笨重的拉曼光谱仪器严重阻碍了其应用范围的进一步扩大。利用阵列波导光栅（AWG）的原理研制色散芯片取代原来的光栅、透镜组成的光学系统，将会使拉曼光谱仪器的体积和价格下降一个数量级以上，在检测仪器和方法方面，将对缓解我国目前严峻的食品安全形势具有重大意义。通过针对微型拉曼光谱仪对阵列波导光栅的技术要求进行分析研究，我们提出了新型的AWG分光芯片，我们通过设计具有等弯曲半径的阵列波导和引入抛物线型的楔形波导结构来降低了器件的插入损耗。针对性地开展理论建模、仿真优化和工艺研制研究，最终在理论上获得拉曼光谱仪专用的AWG 色散芯片的设计理论和优化算法，通过设计仿真、制作加工、器件测试，获得了用于微型拉曼光谱仪分光芯片的阵列波导器件。测试结果表明，设计和制备的AWG器件的性能指标基本符合预期目标。最终实现了40通道的AWG器件，波长范围为800nm-1000nm，插入损耗为-6.55dB。总之，本项目验证了将阵列波导光栅用于微型拉曼光谱仪分光芯片的思路，实现了微型拉曼光谱仪用AWG芯片的设计仿真、加工制备以及测试方法，为实现低成本、微型化和高光谱分辨率的微型拉曼光谱仪初步打下了一定的研究基础。