Doctor of Philosophy / Department of Physics / Zenghu Chang / The observation and control of dynamics in atomic and molecular targets requires the use
of laser pulses with duration less than the characteristic timescale of the process which is to be manipulated. For electron dynamics, this time scale is on the order of attoseconds where 1
attosecond = 10[superscript]-18 seconds. In order to generate pulses on this time scale, different gating methods have been proposed. The idea is to extract or “gate” a single pulse from an attosecond pulse train and switch off all the other pulses. While previous methods have had some success, they are very difficult to implement and so far very few labs have access to these unique light sources. The purpose of this work is to introduce a new method, called double optical gating (DOG), and to demonstrate its effectiveness at generating high contrast single isolated attosecond pulses from multi-cycle lasers. First, the method is described in detail and is investigated in the spectral domain. The resulting attosecond pulses produced are then
temporally characterized through attosecond streaking. A second method of gating, called
generalized double optical gating (GDOG), is also introduced. This method allows attosecond
pulse generation directly from a carrier-envelope phase un-stabilized laser system for the first
time. Next the methods of DOG and GDOG are implemented in attosecond applications like
high flux pulses and extreme broadband spectrum generation. Finally, the attosecond pulses
themselves are used in experiments. First, an attosecond/femtosecond cross correlation is used
for characterization of spatial and temporal properties of femtosecond pulses. Then, an
attosecond pump, femtosecond probe experiment is conducted to observe and control electron
dynamics in helium for the first time.
| Identifer | oai:union.ndltd.org:KSU/oai:krex.k-state.edu:2097/4250 |
| Date | January 1900 |
| Creators | Gilbertson, Steve |
| Publisher | Kansas State University |
| Source Sets | K-State Research Exchange |
| Language | en_US |
| Detected Language | English |
| Type | Dissertation |
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