Molecular switch assisted planar polymer waveguide arrays for integrated optical sensing

该项目的目标是开发基于平面聚合物-光波导结构的新型光学传感器概念，这种结构由分子可开关材料功能化。这两种材料系统的组合旨在提供具有量身定制的光学性能的集成波导结构，该结构可以使用纯光学原理灵敏地捕获环境中的物理量或化学量，例如酸碱度、湿度和温度，从而为传感提供一种新的、灵活的和资源高效的复合材料类别。作为各种参数的函数，将研究波导结构的光学性质的变化：(I)集成在波导阵列中或其上以进行功能化的定制的可开关分子络合物(纳米材料)的自旋的变化，(Ii)聚合物与可开关分子络合物的掺杂的影响，以及(Iii)波导几何形状的影响。为此，有必要设计可切换的分子，使它们对各种外部刺激，如温度、湿度或环境中某些化合物(例如，酸或碱)的存在，即折射率的变化，做出反应，从而改变它们的光学性质，例如，吸收行为或分子尺寸。科学上的挑战是：(I)新型聚合物波导阵列的制造，其中光传播通过可切换分子络合物的定向插入/应用来控制，(Ii)可切换分子络合物在波导结构中的定制各向异性分布，其改变材料特性和波导结构外部的消失场，(Iii)能够多路复用的结构的产生，其在波导的某些区域累积这些可切换分子，从而创建不同物理量和化学量的传感器区域，该项目的最终目标是首次开发新型聚合物光纤结构，并与定制的分子开关相结合，以控制所产生的复合材料系统的光学性能，并为新的集成光学传感器应用提供基础。

The aim of this project is the development of novel optical sensor concepts based on planar polymer-optical waveguide structures, which are functionalized with molecular switchable materials. The combination of these two material systems is intended to provide integrated waveguide structures with tailored optical properties that can sensitively capture physical or chemical quantities in the environment such as acidity/basicity, humidity and temperature using purely optical principles, thus, providing a new, flexible and resource-efficient class of composite materials for sensing. The change in the optical properties of the waveguide structures will be investigated as a function of various parameters: (i) the change in the spin of the tailored switchable molecular complexes (nanomaterials) which are integrated in or on the waveguide arrays for functionalization, (ii) the influence of the doping of the polymers with the switchable molecular complexes and (iii) the influence of waveguide geometry. For this purpose, it is necessary to design the switchable molecules so that they react to various external stimuli such as temperature, humidity or the mere presence of certain chemical compounds in their environment (e.g. acids or bases), i.e. a change in the refractive index, and, consequently, change their optical properties, for example, the absorption behavior or the molecular size. The resulting perturbation, in turn, affects the light propagation in the material and will be employed for optical signal generation and, thus, for sensing.The scientific challenges are: (i) the fabrication of novel polymer waveguide arrays, where light propagation is controlled by targeted insertion/application of switchable molecular complexes, (ii) the tailored anisotropic distribution of switchable molecular complexes in the waveguide structures that change the material properties and the evanescent field outside the waveguide structures, (iii) the generation of multiplex-capable structures that accumulate these switchable molecules in certain areas of the waveguides and, thus, create sensor areas of different physical and chemical quantities, as well as (iv) the exact quantification of the tailored optical properties and their evaluation for photonic applications, i.e. optical sensors or lab-on-chip systems.The ultimate goal of this project is the first-time exploitation of novel polymer fiber optic structures in combination with tailored molecular switches to control the optical properties of the resulting composite material systems and provide the foundations for new integrated optical sensor applications.