DOCTORAL CANDIDATE 11

This project will build new external cavity interband cascade lasers specifically optimised for photothermal spectroscopy measurements of proteins, combining ICL gain chips with meta surface mirrors to realise a ground-breaking Metasurface Hybrid External Cavity ICL. The gain chip will be realised at NP (with DC1). The ICL chips will be designed to shown broad gain covering the target spectral region, ultimately from 1700cm-1 (5,88 μm) to 1500 cm-1 (6,67 μm). The waveguide will be curved to minimise back reflections and coatings applied if required. First designs will be targeting shorter wavelengths, such as 4,25 μm. Combining metasurfaces with the gain material will result in broadly tuneable lasers avoiding any moving parts. These planned designs will be used to provide for extremely narrow linewidth (single longitudinal mode) and ultra-stable lasing. The laser will be designed to cover the absorption bands selected by DC2,5. The design and fabrication of the metasurfaces will be performed at MTU whereas the ICL chip will be realized at NP. DC11 will work with DCs 3 and 5 to determine the optimum laser specifications to extract spectroscopic instrumentation for the proteins of interest.