Molecular switch assisted planar polymer waveguide arrays for integrated optical sensing

该项目的目的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，该结构用分子可切换材料功能化。这两种材料系统的组合旨在提供具有定制的光学特性的集成波导结构，其可以使用纯光学原理灵敏地捕获环境中的物理或化学量，例如酸度/碱度、湿度和温度，从而提供用于感测的新型、灵活且资源高效的复合材料。波导结构的光学性质的变化将作为各种参数的函数进行研究：（i）集成在波导阵列中或波导阵列上用于功能化的定制的可切换分子复合物（纳米材料）的自旋的变化，（ii）用可切换分子复合物掺杂聚合物的影响，以及（iii）波导几何形状的影响。为此目的，有必要设计可切换分子，使得它们对各种外部刺激（例如温度、湿度或在它们的环境中仅仅存在某些化合物（例如酸或碱））（即折射率的变化）起反应，并且因此改变它们的光学性质，例如吸收行为或分子尺寸。由此产生的扰动反过来会影响材料中的光传播，并将用于光信号生成，从而用于传感。科学挑战是：（i）新型聚合物波导阵列的制造，其中通过可切换分子复合物的定向插入/应用来控制光传播，（ii）波导结构中的可切换分子复合物的定制各向异性分布，其改变波导结构外部的材料性质和倏逝场，（iii）产生能够复用的结构，该结构在波导的某些区域中积累这些可切换分子，并且因此产生不同物理和化学量的传感器区域，以及（iv）定制光学性质的精确量化及其对光子应用的评估，即光学传感器或芯片实验室系统。该项目的最终目标是首次开发新型聚合物光纤结构与定制分子开关的组合，以控制所得复合材料系统的光学特性，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.