Physics (Internal)

Ultrafast infrared fiber lasers and applications in mid-infrared vibrational photothermal imaging

This event is part of the Biophysics/Condensed Matter Seminar Series.

Thulium(Tm)/Holmium(Ho) co-doped fibers have recently moved into the focus of research due to a broadband gain emission window around 2µm and attractive applications in spectroscopy, LIDAR, biomedical treatment and diagnosis. In this talk, we will outline pathways to achieve low noise, high repetition rate ultrafast lasers in a versatile linear Tm/Ho fiber laser cavity. In the second part of the talk we will focus on a mid-infrared photothermal spectroscopy system that combines a mid-infrared quantum cascade laser with one of our custom-designed fiber laser. Mid-infrared spectral imaging in the fingerprint region (at wavelengths ~5μm and longer) can reveal characteristic details about molecular compounds and secondary structure of chemicals and biomolecules. A contact-less, non-destructive mid-infrared imaging system with high sensitivity and specificity based on vibrational photothermal spectroscopy will be presented. Scaling of the pump power a nonlinear photothermal spectroscopy regime promises a novel multi-dimensional characterization method for materials with enhanced sensitivity with improved spatial resolution. Applications of the presented system can range from chemical trace hazardous material detection, to identification of neurodegenerative diseases based on secondary protein configurations, remote sensing and process control.