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Photonics

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Articles 31 - 35 of 35

Full-Text Articles in Optics

Optically Isotropic Liquid Crystals For Display And Photonic Applications, Jin Yan Jan 2013

Optically Isotropic Liquid Crystals For Display And Photonic Applications, Jin Yan

Electronic Theses and Dissertations

For the past few decades, tremendous progress has been made on liquid crystal display (LCD) technologies in terms of stability, resolution, contrast ratio, and viewing angle. The remaining challenge is response time. The state-of-the-art response time of a nematic liquid crystal is a few milliseconds. Faster response time is desirable in order to reduce motion blur and to realize color sequential display using RGB LEDs, which triples the optical efficiency and resolution density. Polymer-stabilized blue phase liquid crystal (PS-BPLC) is a strong candidate for achieving fast response time because its self-assembled cubic structure greatly reduces the coherence length. The response …


Non-Reciprocal Wave Transmission In Integrated Waveguide Array Isolators, Tony Yatming Ho Jan 2012

Non-Reciprocal Wave Transmission In Integrated Waveguide Array Isolators, Tony Yatming Ho

Electronic Theses and Dissertations

Non-reciprocal wave transmission is a phenomenon witnessed in certain photonic devices when the wave propagation dynamics through the device along one direction differs greatly from the dynamics along the counter-propagating direction. Specifically, it refers to significant power transfer occurring in one direction, and greatly reduced power transfer in the opposite direction. The resulting effect is to isolate the directionality of wave propagation, allowing transmission to occur along one direction only. Given the popularity of photonic integrated circuits (PIC), in which all the optical components are fabricated on the same chip so that the entire optical system can be made more …


Afm-Patterned 2-D Thin-Film Photonic Crystal Analyzed By Complete Angle Scatter, Nicholas C. Herr Mar 2010

Afm-Patterned 2-D Thin-Film Photonic Crystal Analyzed By Complete Angle Scatter, Nicholas C. Herr

Theses and Dissertations

The purpose of this research was to use an atomic force microscope (AFM) to generate a 2-D square array of sub-wavelength surface features from a single material over a region large enough to permit optical characterization. This work is an extension of previous AFIT nano-patterning work and is in response to the small subunit sizes demanded for the production of optical metamaterials and photonic crystals. A diamond nano-indentation AFM probe was used to produce a 325-μm by 200-μm array of indentations in a 120-nm thick polystyrene film deposited on silicon. Indentation spacing of 400 nm produced well-defined surface features with …


Micro-Optic-Spectral-Spatial-Elements (Mosse), Alok Ajay Mehta Jan 2007

Micro-Optic-Spectral-Spatial-Elements (Mosse), Alok Ajay Mehta

Electronic Theses and Dissertations

Over a wide range of applications, optical systems have utilized conventional optics in order to provide the ability to engineer the properties of incident infra-red fields in terms of the transmitted field spectral, spatial, amplitude, phase, and polarization characteristics. These micro/nano-optical elements that provide specific optical functionality can be categorized into subcategories of refractive, diffractive, multi-layer thin film dichroics, 3-D photonic crystals, and polarization gratings. The feasibility of fabrication, functionality, and level of integration which these elements can be used in an optical system differentiate which elements are more compatible with certain systems than others. With enabling technologies emerging allowing …


Design And Assessment Of Compact Optical Systems Towards Special Effects Imaging, Vesselin Chaoulov Jan 2005

Design And Assessment Of Compact Optical Systems Towards Special Effects Imaging, Vesselin Chaoulov

Electronic Theses and Dissertations

A main challenge in the field of special effects is to create special effects in real time in a way that the user can preview the effect before taking the actual picture or movie sequence. There are many techniques currently used to create computer-simulated special effects, however current techniques in computer graphics do not provide the option for the creation of real-time texture synthesis. Thus, while computer graphics is a powerful tool in the field of special effects, it is neither portable nor does it provide work in real-time capabilities. Real-time special effects may, however, be created optically. Such approach …