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Full-Text Articles in Optics

Fabrication And Optical Properties Of Two-Dimensional Transition Metal Dichalcogenides, Manpreet Boora Jan 2023

Fabrication And Optical Properties Of Two-Dimensional Transition Metal Dichalcogenides, Manpreet Boora

Dissertations, Master's Theses and Master's Reports

Two-dimensional layered materials such as graphene and transition metal dichalcogenides have gained a lot of attention because of their distinctive chemical, optical, and electronic properties. Transition metal dichalcogenides can have a tunable bandgap in the range of 1 − 3 eV (visible), which enables their applications in ultrathin field effect transistors, photovoltaics, sensors, and optoelectronic devices. They exhibit an indirect-to-direct band gap transition when thinned down from bulk to a single layer. They show strong photoluminescence, electron–photon interaction, valley pseudospin, nonlinear optical response, and lack of dangling bonds. Many exotic phenomena appear when materials are thinned to nanoscale size because …


Light Field Compression And Manipulation Via Residual Convolutional Neural Network, Eisa Hedayati Jan 2021

Light Field Compression And Manipulation Via Residual Convolutional Neural Network, Eisa Hedayati

Dissertations, Master's Theses and Master's Reports

Light field (LF) imaging has gained significant attention due to its recent success in microscopy, 3-dimensional (3D) displaying and rendering, augmented and virtual reality usage. Postprocessing of LF enables us to extract more information from a scene compared to traditional cameras. However, the use of LF is still a research novelty because of the current limitations in capturing high-resolution LF in all of its four dimensions. While researchers are actively improving methods of capturing high-resolution LF's, using simulation, it is possible to explore a high-quality captured LF's properties. The immediate concerns following the LF capture are its storage and processing …


Optical Vortex And Poincaré Analysis For Biophysical Dynamics, Anindya Majumdar Jan 2019

Optical Vortex And Poincaré Analysis For Biophysical Dynamics, Anindya Majumdar

Dissertations, Master's Theses and Master's Reports

Coherent light - such as that from a laser - on interaction with biological tissues, undergoes scattering. This scattered light undergoes interference and the resultant field has randomly added phases and amplitudes. This random interference pattern is known as speckles, and has been the subject of multiple applications, including imaging techniques. These speckle fields inherently contain optical vortices, or phase singularities. These are locations where the intensity (or amplitude) of the interference pattern is zero, and the phase is undefined.

In the research presented in this dissertation, dynamic speckle patterns were obtained through computer simulations as well as laboratory setups …


Comparison Of Computer-Based And Optical Face Recognition Paradigms, Abdulaziz A. Alorf Jan 2014

Comparison Of Computer-Based And Optical Face Recognition Paradigms, Abdulaziz A. Alorf

Dissertations, Master's Theses and Master's Reports - Open

The main objectives of this thesis are to validate an improved principal components analysis (IPCA) algorithm on images; designing and simulating a digital model for image compression, face recognition and image detection by using a principal components analysis (PCA) algorithm and the IPCA algorithm; designing and simulating an optical model for face recognition and object detection by using the joint transform correlator (JTC); establishing detection and recognition thresholds for each model; comparing between the performance of the PCA algorithm and the performance of the IPCA algorithm in compression, recognition and, detection; and comparing between the performance of the digital model …


Integration Of Instrumentation And Processing Software Of A Laser Speckle Contrast Imaging System, Jacob James Carrick Jan 2014

Integration Of Instrumentation And Processing Software Of A Laser Speckle Contrast Imaging System, Jacob James Carrick

Dissertations, Master's Theses and Master's Reports - Open

Laser speckle contrast imaging (LSCI) has the potential to be a powerful tool in medicine, but more research in the field is required so it can be used properly. To help in the progression of Michigan Tech's research in the field, a graphical user interface (GUI) was designed in Matlab to control the instrumentation of the experiments as well as process the raw speckle images into contrast images while they are being acquired. The design of the system was successful and is currently being used by Michigan Tech's Biomedical Engineering department. This thesis describes the development of the LSCI GUI …


Characterization Of The Atmospheric Effects On The Transmission Of Thermal Radiation, Mohamed E. Hanafy Jan 2014

Characterization Of The Atmospheric Effects On The Transmission Of Thermal Radiation, Mohamed E. Hanafy

Dissertations, Master's Theses and Master's Reports - Open

Atmospheric scattering plays a crucial rule in degrading the performance of electro optical imaging systems operating in the visible and infra-red spectral bands, and hence limits the quality of the acquired images, either through reduction of contrast or increase of image blur. The exact nature of light scattering by atmospheric media is highly complex and depends on the types, orientations, sizes and distributions of particles constituting these media, as well as wavelengths, polarization states and directions of the propagating radiation. Here we follow the common approach for solving imaging and propagation problems by treating the propagating light through atmospheric media …


Multi-Wavelength Speckle Reduction For Laser Pico-Projectors Using Diffractive Optics, Weston H. Thomas Jan 2014

Multi-Wavelength Speckle Reduction For Laser Pico-Projectors Using Diffractive Optics, Weston H. Thomas

Dissertations, Master's Theses and Master's Reports - Open

Personal electronic devices, such as cell phones and tablets, continue to decrease in size while the number of features and add-ons keep increasing. One particular feature of great interest is an integrated projector system. Laser pico-projectors have been considered, but the technology has not been developed enough to warrant integration. With new advancements in diode technology and MEMS devices, laser-based projection is currently being advanced for pico-projectors. A primary problem encountered when using a pico-projector is coherent interference known as speckle. Laser speckle can lead to eye irritation and headaches after prolonged viewing. Diffractive optical elements known as diffusers have …


Magneto-Photonic Crystals For Optical Sensing Applications, Neluka Dissanayake Jan 2013

Magneto-Photonic Crystals For Optical Sensing Applications, Neluka Dissanayake

Dissertations, Master's Theses and Master's Reports - Open

Among the optical structures investigated for optical sensing purpose, a significant amount of research has been conducted on photonic crystal based sensors. A particular advantage of photonic crystal based sensors is that they show superior sensitivity for ultra-small volume sensing. In this study we investigate polarization changes in response to the changes in the cover index of magneto-optic active photonic band gap structures. One-dimensional photonic-band gap structures fabricated on iron garnet materials yield large polarization rotations at the band gap edges. The enhanced polarization effects serve as an excellent tool for chemical sensing showing high degree of sensitivity for photonic …


Optical Waveguides And Structures For Short Haul Optical Communication Channels Within Printed Circuit Boards, Nicholas J. Riegel Jan 2013

Optical Waveguides And Structures For Short Haul Optical Communication Channels Within Printed Circuit Boards, Nicholas J. Riegel

Dissertations, Master's Theses and Master's Reports - Open

Optical waveguides have shown promising results for use within printed circuit boards. These optical waveguides have higher bandwidth than traditional copper transmission systems and are immune to electromagnetic interference. Design parameters for these optical waveguides are needed to ensure an optimal link budget. Modeling and simulation methods are used to determine the optimal design parameters needed in designing the waveguides. As a result, optical structures necessary for incorporating optical waveguides into printed circuit boards are designed and optimized.

Embedded siloxane polymer waveguides are investigated for their use in optical printed circuit boards. This material was chosen because it has low …


Direct Write Fabrication Of Waveguides And Interconnects For Optical Printed Wiring Boards, Joseph Carl Dingeldein Jan 2012

Direct Write Fabrication Of Waveguides And Interconnects For Optical Printed Wiring Boards, Joseph Carl Dingeldein

Dissertations, Master's Theses and Master's Reports - Open

Current copper based circuit technology is becoming a limiting factor in high speed data transfer applications as processors are improving at a faster rate than are developments to increase on board data transfer. One solution is to utilize optical waveguide technology to overcome these bandwidth and loss restrictions. The use of this technology virtually eliminates the heat and cross-talk loss seen in copper circuitry, while also operating at a higher bandwidth. Transitioning current fabrication techniques from small scale laboratory environments to large scale manufacturing presents significant challenges. Optical-to-electrical connections and out-of-plane coupling are significant hurdles in the advancement of optical …