Photoinduced dynamics studied by ultrafast single-shot pump-probe spectroscopy

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.

Name thesis:degree_name

Doctoral

Department dc:contributor.department

Massachusetts Institute of Technology. Department of Electrical Engineering and Computer Science

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

2019

Author dc:creator

• Cheng, Yu-Hsiang.

Advisor dc:contributor.advisor

• Keith A. Nelson.

• Electrical Engineering and Computer Science.

Statement dc:rights

• MIT theses are protected by copyright. They may be viewed, downloaded, or printed from this source but further reproduction or distribution in any format is prohibited without written permission.

Licence dc:rights.uri

• http://dspace.mit.edu/handle/1721.1/7582

Language dc:language.iso

eng

Handle dc:identifier.uri

https://hdl.handle.net/1721.1/122684

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/122684