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Full-Text Articles in Physics

Single-Stage Few-Cycle Pulse Amplification, Sagnik Ghosh, Nathan G. Drouillard, Tj Hammond Jan 2024

Single-Stage Few-Cycle Pulse Amplification, Sagnik Ghosh, Nathan G. Drouillard, Tj Hammond

Physics Publications

Kerr instability can be exploited to amplify visible, near-infrared, and midinfrared ultrashort pulses. We use the results of Kerr instability amplification theory to inform our simulations amplifying few-cycle pulses. We show that the amplification angle dependence is simplified to the phase-matching condition of four-wave mixing when the intense pump is considered. Seeding with few-cycle pulses near the pump leads to broadband amplification without spatial chirp, while longer pulses undergo compression through amplification. Pumping in the midinfrared leads to multioctave spanning amplified pulses with single-cycle duration not previously predicted. We discuss limitations of the amplification process and optimizing pump and seed …


Measurement Of Dispersion And Index Of Refraction Of 1-Decanol With Spectrally Resolved White Light Interferometry, Nathan G. Drouillard, Tj Hammond Jan 2022

Measurement Of Dispersion And Index Of Refraction Of 1-Decanol With Spectrally Resolved White Light Interferometry, Nathan G. Drouillard, Tj Hammond

Physics Publications

The high density, high nonlinearity, and stability of liquids make them an attractive medium for spectral broadening and supercontinuum generation in ultrafast experiments. To understand ultrashort pulse propagation in these media, their indices of refraction and dispersions must be characterized. We employ a Mach-Zehnder interferometer to generate a series of interferograms, which we refer to as a spectrogram, to develop a new method of using spectrally resolved white light interferometry to determine the refractive indices of materials. We determine the indices of refraction of BK7, sapphire, ethanol, and 1-decanol at 24°C across the visible and near infrared. To our knowledge, …


Femtosecond Pulse Compression Via Self-Phase Modulation In 1-Decanol, Jacob A. Stephen Jan 2022

Femtosecond Pulse Compression Via Self-Phase Modulation In 1-Decanol, Jacob A. Stephen

Electronic Theses and Dissertations

Ultrafast science is a branch of photonics with far reaching applications in and outside the realm of physics. Ultrashort laser pulses on the order of femtoseconds (1 fs = 1 × 10−15 s) are widely used for ultrafast science. Many lasers can produce pulses on the order of 100 fs, with state of the art, high end lasers being capable of producing pulses around 30 fs. However, many experiments require pulses around 10 fs or shorter. Femtosecond pulses are typically generated using spectral broadening via self-phase modulation, followed by dispersion compensation. The most common spectral broadening technique exploits the nonlinear …


Pathogen Identification With Laser-Induced Breakdown Spectroscopy: The Effect Of Bacterial And Biofluid Specimen Contamination, Q.I. Mohaidat, K. Sheikh, S. Palchaudhuri, Steven J. Rehse Jan 2012

Pathogen Identification With Laser-Induced Breakdown Spectroscopy: The Effect Of Bacterial And Biofluid Specimen Contamination, Q.I. Mohaidat, K. Sheikh, S. Palchaudhuri, Steven J. Rehse

Physics Publications

In this paper, the potential use of laser-induced breakdown spectroscopy (LIBS) for the rapid discrimination and identification of bacterial pathogens in realistic clinical specimens is investigated. Specifically, the common problem of sample contamination was studied by creating mixed samples to investigate the effect that the presence of a second contaminant bacterium in the specimen had on the LIBS-based identification of the primary pathogen. Two closely related bacterial specimens, Escherichia coli strain ATCC 25922 and Enterobacter cloacae strain ATCC 13047, were mixed together in mixing fractions of 10:1, 100:1, and 1000:1. LIBS spectra from the three mixtures were reliably classified as …