<p> With the development of ultra-fast laser technology, several new imaging techniques have pushed optical resolution past the diffraction limit for traditional light-based optics. Advancements in lithography have enabled the straightforward creation of micron- and nanometer-sized optical devices. Exposing metal-dielectric structures to light can result in surface plasmon excitation and propagation along the transition interface, creating a surface plasmon polariton (SPP) response. Varying the materials or geometry of the structures, the plasmonic response can be tailored for a wide range of applications. </p><p> Photoemission electron microscopy (PEEM) has been used to image excitations in micron-sized plasmonic devices. With PEEM, optical responses can be characterized in detail, aiding in the development of new types of plasmonic structures and their applications. We show here that in thin, triangular gold platelets SPPs can be excited and concentrated within specific regions of the material (thickness ~50 nm); resulting in localized photoemission in areas of high electric field intensity. In this regard, the platelets behave as receiver antennas by converting the incident light into localized excitations in specific regions of the gold platelets. The excited areas can be significantly smaller than the wavelength of the incident light (&lambda; &le; 1 &micro;m). By varying the wavelength of the light, the brightness of the excited spots can be changed and by varying the polarization of the light, the brightness and position can be changed, effectively switching the photoemission on or off for a specific region within the triangular gold structure. </p><p> In this work, the spatial distribution of surface plasmons and the imaging results from photoemission electron microscopy are reproduced in simulation using finite element analysis (FEA). In addition, we show that electromagnetic theory and simulation enable a detailed and quantitative analysis of the excited SPP modes, an explanation of the overall optical responses seen in PEEM images, and prediction of new results.</p><p>

A simple model for optical pulse propagation in a nondegenerate two-level amplifying medium is considered, under the assumption of extreme Doppler broadening. Starting with a "Pade approximant" left reflection coefficient with N simple poles and N$\sb{\rm b}\leq$ N bound states, and employing Lamb's one-component inverse scattering method*, pulses whose initial area can be $>\pi$ are obtained. Then, employing the asymptotic behavior of the eigenvalues of the kernel of the right Marchenko equation, the asymptotic behavior of the pulses far into the medium is analyzed in detail when N $\leq$ 3. In addition to the expected portion of area $\pi$ near the light cone which undergoes amplification and compression, pulses with a continuous leading edge develop forward-moving oscillations, and some pulses trail behind one or more 2$\pi$ (or 0$\pi$) solitons. Pulses whose final area is $\pi$, 3$\pi$, and 5$\pi$ are obtained. Interestingly, the number of trailed solitons is in general not equal to the number of bound states. These solitons are associated with a subset of the zeroes of the transmission coefficient rather than of its poles. Conditions for the appearance of a soliton are given in terms of the poles and residues of the left reflection coefficient. A connection is established between the values of the pulse profiles and their first 2N $-$ 1 derivatives at the light cone, and the residue and pole parameters of the left reflection coefficient. For N = 2 and the case in N = 3 where the pulse has a continuous leading edge, simple conditions for the appearance of a soliton are obtained in terms of the values of the pulse profiles and their first N $-$ 1 derivatives at the light cone, and the poles of the left reflection coefficient. It is established for N $\leq$ 3 that for each 2$\pi$ soliton there is a purely imaginary zero of the left reflection coefficient / in the lower half $\nu$ plane and that for a 0$\pi$ soliton there are a pair of zeroes of the left reflection coefficient lying symmetrically about the negative imaginary $\nu$ axis. ftn*G. L. Lamb, Jr., Phys. Rev. A 12, 2052 (1975). / Source: Dissertation Abstracts International, Volume: 49-03, Section: B, page: 0806. / Major Professor: J. Daniel Kimel. / Thesis (Ph.D.)--The Florida State University, 1987.

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No description available.

No description available.

Thesis (Ph.D.)--Lehigh University, 2009. / Adviser: Boon S. Ooi.

<p> With the advent of microsphere assisted microscopy in 2011, this technique emerged as a simple and easy way to obtain optical super-resolution. Although the possible mechanisms of imaging by microspheres are debated in the literature, most of the experimental studies established the resolution values well beyond the diffraction limit. It should be noted, however, that there is no standard resolution measurement in this field that researchers can use. The reported resolution has been based on the smallest discernible feature; although it seems logical but it is not based on the standard textbook definition, and so far it has ended to a wide range of resolution reports based on qualitative criteria which can lead to exaggerated resolution values. In addition, this method has another limitation related to its limited field-of-view. In this work, first we fabricated a novel optical component for super-resolution imaging based on an attachable polydimethylsiloxane (PDMS) thin film with embedded high index (<i>n</i>~2) barium titanate glass (BTG) microspheres. It is shown that such films can be translated along the surface of investigated structures to enhance field-of-view. Second, we introduced a method of image treatment which allows determining the super-resolution values consistent with the resolution definition in the conventional diffraction-limited optics. We demonstrated this method for a typical microsphere-assisted image where we measured the super-resolution of ~&lambda;/5.5. We also developed this technique to measure the resolution of a micro-cylindrical-assisted system. </p>

<p> In this dissertation I present theory and experimental results obtained in the Jones research group at the University of Arizona investigating the feasability of neutral Hg as a candidate for an atomic clock. This investigation includes laser-cooling and trapping of several neutral Hg isotopes as well as spectroscopy of the 6¹<i>S</i>₀ - 6³<i>P</i>₀ doubly forbidden clock transition in neutral Hg¹⁹⁹. </p><p> We demonstrate precision spectroscopy of the ground state cooling/trapping transition of neutral mercury at 254 nm using an optically pumped semiconductor laser (OPSL). This demonstration exhibits the utility of optically pumped semiconductor lasers (OPSLs) in the field of precision atomic spectroscopy. The OPSL lases at 1015 nm and is frequency quadrupled to provide the trapping light for the ground state cooling transition. We get up to 1.5 W single-frequency output power having a linewidth of &lt;10 kHz in the IR with active feedback. We frequency quadruple the OPSL in two external cavity stages to produce up to 120 mW of deep-UV light at 253.7 nm. </p><p> I give a detailed characterization of the construction and implementation of the neutral Hg vapor cell magneto-optical trap (MOT). The trap can be loaded in as quickly as 75 ms at background vapor pressures below 10^-8 torr. At reduced background pressure (&lt;10^-10 torr) the loading time approaches &sim;2 sec. </p><p> We describe construction and stabilization of a laser resonant with the Hg¹⁹⁹ clock transition and the methods employed to find and perform the experimentally delicate spectroscopy of the clock transition. We present experimental results and analysis for our initial spectroscopy of the 6¹<i>S</i>₀ - 6³<i> P</i>₀ clock transition in the Hg¹⁹⁹ isotope of neutral mercury.</p>

The scalar Huygens-Fresnel Principle describing the propagation of light is reformulated to take into account the vector nature of light and the associated directed electric and magnetic fields. A vector Huygens secondary source is developed in terms of the fundamental radiating units of electromagnetism: the electric and magnetic dipoles. The vector Huygens wavelets are incorporated into a computer model that calculates the resulting vector fields after light passes through a diffracting system by a wavefront reconstruction process similar to that originally proposed by Huygens himself in 1687. Fresnel and Fraunhofer diffraction patterns are computed for common apertures such as rectangles and circles where theoretical results are available for comparison and validation of the model. However, irregular apertures not easily described in closed mathematical form are studied as well. Both completely absorbing and infinitely conducting screens are considered as well as plane wave and spherical illumination.

An integrated optical waveguide is described that can measure surface concentrations of ions while immersed in an ionic solution, especially the commercially interesting case of ionic copper. Several such sensors were manufactured and tested. The theory behind this measurement technology is described. Techniques for the manufacture and experimental measurement are described. The devices made were able to measure surface concentrations on the order of 10 12 atoms per square centimeter. Several potential methods for improving the performance are given.