Mid-infrared photonic integrated circuits (PICs) are a novel type of functional optoelectronic devices for spectroscopy, that combine multiple elements such as lasers, detectors, waveguides, modulators and/or filters on one single chip. 
In this PhD thesis the next generation of such functional mid-infrared PICs will be developed. A special focus is put on the passive components, i.e. waveguides and modulators, as crucial elements, that so far still lack maturity on the currently available PICs. 
To achieve this, the candidate will work with state of the art design tools to model and optimize these passive elements as part of the whole chip, contribute to the process design of the final devices and be part of the team of their fabrication in our state-of-the-art cleanroom. The final mid-infrared PICs will then be characterized and used in on-chip sensing experiments.  

The research will involve:

• Design and development of novel mid-infrared photonic integrated circuits (PICs) with a focus on passive components (low-loss waveguides, efficient splitters/combiners, high-speed modulators, optical filters) for sensing applications
• Explore novel concepts & thin film-based material systems
• Integrate (monolithic, hybrid) the passive components with active mid-infrared lasers and detectors based on well-known III-V material systems (InP, InAs, GaSb)
• Develop fabrication processes for the photonic devices in the R&D cleanroom facilities and in collaboration with the process engineers  
• Conduct electro-optical testing of the devices for optimizing the design 
• Participate in first sensing experiments with external partners from academia and industry 
• Be part of the scientific dissemination of the results (conferences, journal papers, patents)