Pulse propagation through a slab with a time-periodic dielectric function Ɛ(t)
In this thesis we embark in the study of the electromagnetic interaction between a pulse and an active or dynamic slab whose dielectric function varies periodically in time. In a recent paper [Zurita-Sánchez, Halevi, and Cervantes-González, Phys. Rev. A 79, 053821 (2009)], the basic properties of a...
| Autor: | |
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| Tipo de recurso: | tesis de maestría |
| Estado: | Versión aceptada para publicación |
| Fecha de publicación: | 2010 |
| País: | México |
| Institución: | Instituto Nacional de Astrofísica, Óptica y Electrónica |
| Repositorio: | Repositorio Institucional del INAOE |
| Idioma: | inglés |
| OAI Identifier: | oai:inaoe.repositorioinstitucional.mx:1009/475 |
| Acceso en línea: | http://inaoe.repositorioinstitucional.mx/jspui/handle/1009/475 |
| Access Level: | acceso abierto |
| Palabra clave: | info:eu-repo/classification/Propagación de onda/Wave propagation info:eu-repo/classification/Respuesta dinámica/Dynamic responce info:eu-repo/classification/Velocidad/Velocity info:eu-repo/classification/cti/1 info:eu-repo/classification/cti/22 info:eu-repo/classification/cti/2203 |
| Sumario: | In this thesis we embark in the study of the electromagnetic interaction between a pulse and an active or dynamic slab whose dielectric function varies periodically in time. In a recent paper [Zurita-Sánchez, Halevi, and Cervantes-González, Phys. Rev. A 79, 053821 (2009)], the basic properties of a dynamic dielectric medium whose dielectric constant varies harmonically with time (angular frequency W) were established. It was found, in particular, that the group velocity becomes infinite at frequencies that are integer multiples of W 2 . In response to these divergences, herein the pulse transmission through a slab of dynamic-periodic medium is analyzed. It is found that the peak of a Gaussian pulse, with its carrier frequency tuned to W 2 , traverses the plate with a finite velocity that is smaller than the vacuum speed of light. The peak velocity depends on the plate thickness, the strength of modulation, and the carrier frequency. It is also found that the velocity of the peak oscillates with the thickness of the slab. Such oscillatory behavior is associated with the interference occurring inside the plate. These conclusions are based on detailed numerical calculations of pulse transmission through a dynamic-periodic slab, applied to Gaussian pulses. Numerous graphical results are shown for the transmission and reflection coefficients in both the time- and the frequency-domain. By increasing the strength of modulation, a greater number of harmonics comes into play, distorting the pulse and line shapes. This also results in shifts of the carrier frequency. Finally, it is shown that the transmitted and reflected pulses carry more energy than the incident pulse! This is explained by the fact that we studied an open system; the excess energy is supplied by the external agent that modulates our dynamic medium. |
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