Department of Physics, NCU
Demonstration and applications of Light-wave optoelectronics and nonlinear light microscopy enabled by precise femtosecond laser generation
賈世璿教授 (Prof. Shih-Hsuan Chia)
陽明大學生醫光電所(Institute of Biophotonics, NYMU)
Date 2020.09.29 (Tue)
Abstract: A better understanding of mode-locking mechanisms and nonlinear optical processes leads to the demonstrations of advanced femtosecond sources, enabling the explorations of the research/industry frontiers, such as precision metrology, ultrafast dynamics, and microscopy applications. In this talk, I will firstly discuss the analyses of (1) the spatiotemporal laser physics behind octave-spanning Ti:sapphire lasers and (2) nonlinear fiber optics for coherent supercontinuum generation. The analyses rely on proper modeling the roles of optical Kerr nonlinearity, dispersion, diffraction, gain features of Ti:sapphire crystals (i.e., gain cross section, gain saturation, and the geometry of the pump beam), and multiphoton ionization processes, and resulting in useful guidelines to demonstrate state-of-the-art femtosecond generations, such as shorter pulse generation from a single laser oscillator and lower-noise supercontinuum generation. The optimized femtosecond laser sources have been applied and shown their uniqueness for (1) optical-field-controlled photoemission from plasmonic nanoparticles and (2) compact nonlinear microscopy for biomedical applications.