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"Half-cycle mid-infrared field waveforms from hollow-fiber pulse self-compression"

Dr. Aleksei Zheltikov
Texas A&M University


Rapidly progressing photonic technologies offer an unprecedented control over optical field waveforms, enabling the generation of extremely brief flashes of electromagnetic radiation with accurately controlled shape, spectrum, and phase. At the forefront of the ongoing quest for ultrashort optical probes that would be capable of resolving extremely fast processes in gas-phase and solid-state systems, technologies allowing the generation of electromagnetic lightwaves with temporal envelopes shorter than the field cycle have been developed, paving the ways toward an ultimate time resolution in electron-dynamic studies and subcycle precision in lightwave sculpting.

Subcycle field waveform generation has been demonstrated for the visible, near-infrared, terahertz, and x-ray ranges. In the mid-infrared region, on the other hand, subcycle field waveform generation is difficult because of the lack of broadband laser materials.

Our recent experiments show, however, that mid-infrared pulses as short as half the field cycle can be generated through a soliton self-compression of a 3.2-µm, 200-fs output of a multicascade optical parametric amplifier in a gas-filled single-ring hollow-core photonic-crystal fiber. With a proper choice of the gas pressure and the fiber length, multioctave supercontinuum field waveforms as short as 3.9 fs are generated right at the fiber output, corresponding to a half-cycle pulse width and >50 pulse compression ratio, without any post-PCF phase compensation.

Tuesday, March 20, 2018
IQSE Seminar Room, 12:00 Noon
(578 MPHY)

Institute for Quantum Science and Engineering
Texas A&M University

(Pizza and salad to be served at 11:30 am)