Solid State & Optics Seminar Series
sponsored by “The Flint Fund Series on Quantum Devices and Nanostructures”
Wednesday, May 15th, 2019
Mann Engineer Student Center - Room 107
(located in Dunham Lab – 10 Hillhouse Ave)
Prof. Michelle Sander
Electrical and Computer Engineering
Infrared laser technology: ultrafast thulium fiber laser dynamics and photothermal vibrational imaging
Fiber lasers have been instrumental to advance fields ranging from telecommunications, sensing, material manipulation to medicine based on their compact light delivery, robustness and versatility. With femtosecond pulse durations, new nonlinear phenomena can be studied and glimpses into the dynamics of our universe can be revealed that cannot be captured with conventional electronics.
Thulium fiber lasers operating in the eye-safe wavelength region from 1.7 µm to 2.2 µm will be discussed as emerging sources for short wave infrared light that have fueled state-of-the art applications. A variety of femtosecond laser designs and their underlying pulse dynamics and polarization states for dual output sources and high repetition rates of GHz will be presented.
Insights from infrared light-matter interactions can offer novel pathways for material characterization, imaging, spectroscopy, micromachining and therapeutic approaches. Utilizing photothermal effects, direct modulation of neuronal responses, in particular nerve stimulation and blocking, have been demonstrated and details of inhibiting action potentials in crayfish will be highlighted. Further, we present a mid-infrared photothermal microscope to directly determine intrinsic material properties in a contactless fashion without the need for extensive and intrusive sample preparation relying on external tags, stains or nano-particles. We discuss how this technique can address material analysis challenges of identifying low concentration specimens in nanoscience, chemical processes and pathology. It will be illustrated how this technique can offer sub-diffraction limited resolution for label-free and non-destructive analysis of chemical signatures and subcellular features in tissues.
Host: Prof. Peter Rakich
Yale University, Applied Physics Department