Micro-optical sensors in active fiber composites

Mechanical stress present in components can be described using models and investigations can be performed using appropriate simulation software. With this approach it is possible to determine, how mechanical stress can be minimized by implementation of fibers and how these fibers should be arranged and oriented with respect to the shape of the work piece and with respect to the acting force. However, up to now, there are no measurement methods available which could determine strain and stress spatially resolved within the component, without seriously disturbing the mechanical properties of the work piece. Thus, validation of the simulation results and an active feedback into the simulations is not possible.

The scope of your PhD-theses thus is the investigation, if these measurement needs can minimally invasive be met with micro-optical and especially fiber-optical sensors. Two promising approaches are:

• Implementation of optical fibers with bragg structures into the work piece using specified geometries to determine their 3-dimensional deformation when the part is subjected to external force.
• Direct inscription of surface-waveguides into the work-piece using fs-lasers; it is then possible to inscribe bragg structures into the waveguides, enabling the measurement of deformations. Here the advantage would be that no optical fibers have to be implemented into the device, thus minimizing influence of the properties by the measurement.

You will be working interdisciplinary and examine topics of light-matter-interaction and materials science and connect the mainly experimental work with simulations and advancement and validation of models.

Completed university education in physics, materials sciences or related fields is required, experience with high-power lasers beneficial.