Photoinduced dynamics studied by ultrafast single-shot pump-probe spectroscopy
Name
1124678221-MIT.pdf
Size
7.13 MB
Format
Adobe PDF
Checksum (MD5)
ee8a87eefd892c0ab172c533499f2cd0
Author(s)
Cheng, Yu-Hsiang.
Advisor(s)
Keith A. Nelson.
Date Issued
2019
Publisher
Massachusetts Institute of Technology
Abstract
This thesis focuses on the development of dual-echelon single-shot spectroscopy and its applications to study irreversible photoinduced dynamics. First, the ultrafast laser sources and the related control and characterization techniques are discussed. In particular, we have invented a two-stage dual-beam noncollinear optical parametric amplifier to provide tunable sources for pump-probe spectroscopy. Next, the experimental setup of dual-echelon single-shot spectroscopy is illustrated with great detail and possible noise sources and correction methods are explored. Using the single- shot technique, we studied photoinduced dynamics in three different materials. In bismuth, we found a transition into a transient symmetric phase at high fluences. We showed the coherent control of phonon parameters with pump-pump-probe experiments. We also simulated the carrier and phonon dynamics using a modified two-temperature model. In tellurium, we demonstrated that the amorphization of crystalline tellurium induced by femtosecond pulses is a thermal process. We also estimated the lattice temperature by the change in phonon frequency. In a strained manganite film, we observed a photoinduced persistent insulator-to-metal transition and showed the partial recovery of the generated metallic phase to the insulating phase.
Description
This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.
Thesis: Ph. D., Massachusetts Institute of Technology, Department of Electrical Engineering and Computer Science, 2019
Cataloged from student-submitted PDF version of thesis.
Includes bibliographical references (pages 155-168).
Subjects
Electrical Engineering and Computer Science.
MIT Department
Massachusetts Institute of Technology. Department of Electrical Engineering and Computer Science
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