Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
Results
Showing 1 to 20 of 23 for “"self-focusing"”.
-
Femtosecond Pulse Compression via Self-Phase Modulation in 1-Decanol
… generated using spectral broadening via self-phase modulation, followed by dispersion compensation. The most common spectral broadening technique exploits the nonlinear interaction of intense pulses focused into gas-filled hollow-core fibres. More recently, multiple crystal plates have …
-
INVESTIGATION OF THE NONLINEAR INDEX OF REFRACTION OF WATER AT 815 AND 407 NANOMETERS
… achieve remote underwater pulse compression and self-focusing.
-
Intensyvių femtosekundinių šviesos bangų paketų sklidimo Kero terpėse laikinis ir erdvinis charakterizavimas /
In the disertation, the self-focusing phenomenon of intense femtosecond light pulses in media with cubic nonlinearity is investigated and the origin of formation of light filaments is revealed. In this work, new measurement techniques are introduced and applied experimentally, which allowed high …
-
Numerical detection of complex singularities in two and three dimensions
… of shock fronts in hyperbolic equations and self-focusing type blow up in nonlinear parabolic equations. Information about formation and structure of singularities can have significant role in interfacial fluid dynamics such as Kelvin-Helmholtz instability, Rayleigh-Taylor instability, and …
-
On the Role of Linear Processes in the Development and Evolution of Filaments in Air
… exceedinga certain critical value (Pcr) undergo self-focusingleading to collapse and filamentation. During the initial stagesof propagation at low intensities the beamdynamics are dominated by diffraction and dispersion. During filamentation, self-focusing resulting from the nonlinear Kerr effect …
-
BELIEFS ABOUT RELIGION AND SPIRITUALITY AMONG SUBSTANCE ABUSE COUNSELORS
… are able to implement the professional use of self-focusing more on the client’s needs as opposed to theirs. The implication for future research is the contribution to extant literature by emphasizing the importance of religious or spiritual practices in the recovery process.</p>
-
Iterative nonlinear beam propagation method and its application in nonlinear devices
… with common Kerr effect phenomena such as self-focusing and spatial solitons. As the application to the analysis of nonlinear optical devices, this method is applied to nonlinear Lineburg lens. It is found that the nonlinear Liineburg lens is able to compensate the focal shift caused by the …
-
Nonlinear Light - Matter Interactions of Ultrafast High Intensity Laser Pulses
… supercontinuum (SC), stimulated Raman (SRS), self-focusing and filamentation, conical emission (CE), and the various components of the Kerr effect. The ultrashort nature of modern laser pulses also allows for these ultrafast processes to be measured in time using the pump-probe technique.</p> …
-
Deposition and Erosion of El Mar: Utilizing Storytelling to Analyze the Woman of Color Assistant Principal Identity
… women of color assistant principals. The ideal self is defined by Boyatzis and Akrivou (2006) as “an evolving motivational core within the self, focusing a person’s desires and hopes, aspirations and dreams, purpose and calling” (p. 625). It extends work on the changes in their identity before …
-
Optical Filaments and Gas Dynamics in Air
… dynamic balance between linear diffraction, Kerr self-focusing and plasma defocusing. This has led to the development of different theories surrounding the generation and persistence of optical filaments propagating over many Rayleigh lengths in air. These theories include wave-guiding model, …
-
Discrete Nonlinear Wave Propagation In Kerr Nonlinear Media
… This behavior can not be found in continuous self-focusing materials where plane waves are unstable against perturbations. The stability of plane waves in the anomalous diffraction region, even at highest powers, has been experimentally verified. The interaction of high power beams and …
-
Orbital angular momentum and fully structured light in nonlinear media and cavities
… driven by vortices with helical wavefronts. Self-organising hexagonal structures bound in phase lose stability and synchronised oscillations are unstable leading to phaseunbound vortex-mediated turbulence with high excursions in amplitude. Nonlinear amplification leads to rogue waves close to …
-
Predicting the Spatial Output Field of a Laser Beam in a Thermally Self-Induced Inhomogeneous Medium
Laser beam propagation in a thermally self-induced inhomogeneous medium is investigated to find the transient spatial output field for an arbitrary incident field. The paraxial wave equation is coupled with the heat diffusion equation to predict the beam output field as the index of refraction …
-
Strongly Nonlinear Phenomena and Singularities in Optical, Hydrodynamic and Biological Systems
… nonlinear physics, in many situations such as in self-focusing of light nonlinearity is essential part of the model and physical events cannot be captured by linearized equations. There are nonlinear systems, such as $1$D NLSE where singularities in analytic continuation would follow a soliton …
-
Schemes of ion acceleration employing high energy, petawatt laser pulses
… which show significant channelling and self-focusing in the solid hydrogen, greatly enhancing energies of protons accelerated via the hole boring mechanism, and explaining the appearance of the diverging beamlets seen in the RCF profiles for solid hydrogen. Self-focusing down to a width …
-
Orchestrating the Self: Identity Construction in Howard Hanson's Seven Symphonies and "Symphony of Freedom"
… spaces for negotiating a complex sense of self. Focusing on his seven numbered symphonies and his Symphony of Freedom (1949), this project analyzes how Hanson constructed and reimagined various forms of identity through his symphonic output. Rather than treating identity as fixed or …
-
Yummy Mummies, baby bumps and body image : shaping 'Postmodern' pregnancy in Melbourne, Australia
… the maintenance of an appropriate feminine `self . Focusing primarily on dressing, eating, exercise and discourses of `risk', the study suggests that embodied conceptions of selfhood were essential in demonstrating how fraught with difficulties pregnant `body projects' were for informants. …
-
On mechanisms of laser-coupling to fast electrons in ultraintense laser-solid interactions
… show that the enhancement is driven by self-focusing in the underdense region of the plasma density profile, an effect which becomes less effective at longer density scale lengths due to the onset of laser lamentation. In the final experiment an enhancement in electron generation is …
-
Direct Observation of Laser Filamentation in High-Order Harmonic Generation
… mJ, laser pulses were observed to undergo double focusing within the gas cell, with about 4 cm separating the two foci. The region with best harmonic emission occurs midway between the two foci. The radial profile of the laser focus, 150-200 microns in diameter, evolves from a Gaussian-like …
-
Adaptable Design Improvements For Electromagnetic Shock Wave Lithotripters And Techniques For Controlling Cavitation
… original lens was conducted using an integrated, self-focusing annular ring transducer specially designed for tandem pulse lithotripsy. It was found that cavitation and stone comminution efficiency are progressively enhanced by tandem pulsing as source energies of both the primary LSW and trailing …
Page 1 of 2