In modern communications systems, the components supporting wavelength division for increased density are rapidly becoming small compared with the wavelength of light being manipulated. As the size of these devices shrinks there comes a point when the features of interest become smaller than the wavelength and thereby the fundamental properties of light interaction with such structures change dramatically. In these structures and materials, resonances, effective properties, and band-gaps arise and offer designers a new realm of possibilities for the design of high quality factor resonators, filters and switches. / The study of structures comprising two different scales compared with the wavelength of light promises interesting optical possibilities for future devices. In these structures a subwavelength size feature is used in conjunction with a super-wavelength size feature. This thesis will show how the resulting optical behavior for such structures arises from the combination of the sub- and super-wavelength diffractive effects. / Two application examples of these two-scale devices will be studied: the distributed echelle grating and the subwavelength based Fabry-Perot cavity. Both of these applications can be thought, of as distributed diffractive structures, a structure in which diffraction and subwavelength scale interference combine to produce high efficiency and versatile new devices.

No description available.

Thesis (Ph. D.)--Lehigh University, 2000. / Includes vita. Includes bibliographical references (leaves 189-194).

Thesis (Ph.D.)--University of Central Florida, 2009. / Adviser: Leonid B. Glebov. Includes bibliographical references (p. 142-151).

No description available.

No description available.

Thesis (Ph.D.)--Pennsylvania State University, 2007. / Mode of access: World Wide Web.

This thesis contributes to the realisation of plasmonic lasers based on plasmon polariton Bragg gratings. The scope of this thesis is twofold. In the first section, entitled Passive plasmonic Bragg grating characterization, the results of the testing and characterization of a new design of plasmonic Bragg gratings in the near-infrared are presented. The reflection and transmission responses expected from plasmon-polariton Bragg gratings (PPBGs) are treated theoretically using the transfer matrix method (TMM) and the numerical model is validated experimentally. The experimental setup and procedures are then described in detail. Results show that the near-infrared plasmon polariton Bragg gratings possess a Bragg reflection at a wavelength close to the Bragg wavelength predicted by TMM. In the second section, Gain optimisation and bleaching of IR-140 doped PMMA, an in-depth analysis of the gain medium (IR-140 dye doped poly(methyl methacrylate) better known as PMMA) is performed. This gain medium was selected as a gain layer for active plasmonic gratings and distributed feedback lasers designed by a colleague Ph.D. candidate. The optimized molecular weight of IR-140 in PMMA was found to be 0.9% to obtain a material gain of 81 cm-1.

This dissertation includes three separate studies of related waveguide grating phenomena. These studies deal with a numerical improvement of the integral method of diffraction grating theory, the theoretical analysis of waveguide gratings, and fabrication techniques for photoresist grating masks. The first topic addresses the acceleration of the convergence of the integral kernels. To improve the performance of the integral method for calculating diffraction grating efficiencies, the convergence of the integral kernels is studied. A nonlinear sequence transformation, Levin's u-transformation, is successfully applied to accelerate the convergence of the integral kernels. The computer execution time saving is significant. The application details and many numerical examples are given. The second subject is the ray optics theory of waveguide grating analysis. To establish a linkage between the analysis of diffraction gratings and the analysis of waveguide gratings, a new rigorous ray optics theory is developed. It takes into account phase changes on diffraction, multiple diffraction processes, depletion of the incident guided wave, and lateral shifts. A general characteristic equation that determines the waveguide grating attenuation (coupling) coefficient is derived. The symmetry properties of grating diffraction are applied to waveguide grating analysis for the first time. Lateral shifts of optical rays at a periodically corrugated interface similar to the Goos-Haenchen shift at a planar interface are suggested. The third subject is the in situ control of the development of photoresist grating masks. The existing method for monitoring and modeling photoresist grating development are modified and extended to monitoring and modeling photoresist grating mask development. Experimental examples, detailed theoretical considerations, and computer simulations are presented.

The properties of photo-induced gratings in germania doped glass fibers were studied. Permanent phase gratings in a fiber core were fabricated by the mixing of two contra propagating waves. Experiments are described and results are presented which show that the strength of a photoinduced grating is strongly dependent on the writing power as well as the laser writing wavelength. A rigorous development of linear coupled mode theory for the contra propagation geometry is given and used to model the experimentally observed grating responses as a function of fine tuning frequency of probing light. Measurements have been done of the amplitude and phase response of the grating structure and compared with theoretical models of uniform and chirped gratings. The theoretically predicted negative group velocity dispersion in fiber grating was observed interferometrically and described in detail. The nonlinear coupled mode theory has been fully implemented in a computer program and some numerical results are given in the second part of this thesis. The dynamics of a pulse propagating in the fiber grating is simulated and the results show its dependence on pulse energy, frequency detuning, and the type of grating geometry. A limitation is found in the dispersion property of a constant amplitude fiber grating so that the pulse compression ratio and the width of a compressible pulse is strictly limited to ≅250 picoseconds.