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Full-Text Articles in Physics
Polarimetric Characterization Of Random Electromagnetic Beams And Applications, Mircea Mujat
Polarimetric Characterization Of Random Electromagnetic Beams And Applications, Mircea Mujat
Electronic Theses and Dissertations
Polarimetry is one of the principal means of investigating the interaction of light with matter. Theoretical models and experimental techniques are presented in this dissertation for polarimetric characterization of random electromagnetic beams and of signatures of random media in different scattering regimes and configurations. The degree of polarization rather than the full description of the state of polarization is of interest in multiple scattering and free space propagation where the statistical nature and not the deterministic component of light bears the relevant information. A new interferometric technique for determining the degree of polarization by measuring the intensity fluctuations in a …
Stable Spatial Solitons In Semiconductor Optical Amplifiers, Erdem Ultanir
Stable Spatial Solitons In Semiconductor Optical Amplifiers, Erdem Ultanir
Electronic Theses and Dissertations
A spatial soliton is a shape invariant self guided beam of light or a self induced waveguide. Spatial solitons appear as a result of the balance of diffraction and nonlinear focusing in a system. They have been observed in many different conservative media in the last couple of years. Solitons are ubiquitous, because of the probability of using their interactions in optical data processing, communications etc. Up to now due to the power required to generate the solitons, and the response times of the soliton supporting media, these special waves of nature could not penetrate the applications arena. Semiconductors, with …
Chemical Structure - Nonlinear Optical Property Relationships For A Series Of Two-Photon Absorbing Fluorene Molecules, Joel Mccajah Hales
Chemical Structure - Nonlinear Optical Property Relationships For A Series Of Two-Photon Absorbing Fluorene Molecules, Joel Mccajah Hales
Electronic Theses and Dissertations
This dissertation reports on the investigation of two-photon absorption (2PA) in a series of fluorenyl molecules. Several current and emerging technologies exploit this optical nonlinearity including two-photon fluorescence imaging, three-dimensional microfabrication, site-specific photodynamic cancer therapy and biological caging studies. The two key features of this nonlinearity which make it an ideal candidate for the above applications are its quadratic dependence on the incident irradiance and the improved penetration into absorbing media that it affords. As a consequence of the burgeoning field which exploits 2PA, it is a goal to find materials that exhibit strong two-photon absorbing capabilities. Organic materials are …
Evaluation Of The Photo-Induced Structural Mechanisms In Chalcogenide, Cedric Lopez
Evaluation Of The Photo-Induced Structural Mechanisms In Chalcogenide, Cedric Lopez
Electronic Theses and Dissertations
Chalcogenide glasses and their use in a wide range of optical, electronic and memory applications, has created a need for a more thorough understanding of material property variation as a function of composition and in geometries representative of actual devices. This study evaluates compositional dependencies and photo-induced structural mechanisms in As-S-Se chalcogenide glasses. An effective fabrication method for the reproducible processing of bulk chalcogenide materials has been demonstrated and an array of tools developed, for the systematic characterization of the resulting material's physical and optical properties. The influence of compositional variation on the physical properties of 13 glasses within the …
Dispersion-Managed Breathing-Mode Semiconductor Mode-Locked Ring Laser, Bojan Resan
Dispersion-Managed Breathing-Mode Semiconductor Mode-Locked Ring Laser, Bojan Resan
Electronic Theses and Dissertations
A novel dispersion-managed breathing-mode semiconductor mode-locked ring laser is developed. The "breathing-mode" designation derives from the fact that intracavity pulses are alternately stretched and compressed as they circulate around the ring resonator. The pulses are stretched before entering the semiconductor gain medium to minimize the detrimental strong integrating self-phase modulation and to enable efficient pulse amplification. Subsequently compressed pulses facilitate bleaching the semiconductor saturable absorber. The intracavity pulse compression ratio is higher than 50. Down chirping when compared to up chirping allows broader mode-locked spectra and shorter pulse generation owing to temporal and spectral semiconductor gain dynamics. Pulses as short …