Tuning of the reflection and spontaneous emission of a one-dimensional photonic crystal
ELIZABETH GALINDO LINARES
In this thesis I consider tuning of the optical response of a one-dimensional photonic crystal. The optical response is represented by (a) re ectance and (b) spontaneous emission. In both cases the photonic crystal is constituted from alternating silicon (Si) and silica (SiO2) layers. The density of free carriers in the Si layers is modulated at a level of 1019=cm3, the wavelength of light being xed at 1:54m. (a) I calculate the tuning of re ectance of a one-dimensional photonic crystal (PC) by means of charge injection. The PC is constituted from highly doped Si layers alternating with SiO2 layers. The wavelength of the light is assumed to be the important communications wavelength of 1:54m. A realistic calculation shows that sensitive tuning, and switching as well, can be achieved for an impurity density 1019=cm3 even for superlattices (SLs) only a few periods long. The re ectance results are satisfactorily interpreted in terms of photonic band (PB) structure calculations. (b) If the modal density available to an excited atom is varied on the time scale of its lifetime, then we can expect the natural process of spontaneous emission (SE) to become dynamically manipulable. I consider various experimental possibilities and focus on an atom embedded in a PC designed to have a band edge in the vicinity of the frequency of the emitted light. Specifically, I calculate the rate of SE by erbium ions (radiating at the wavelength 1:54m) implanted in a one-dimensional Si/SiO2 PC. The semiconductor layers are assumed to be strongly doped; by tuning the impurity density the free carrier concentration changes and the PBs shift. As a result, the SE rate exhibits signicant dependency on the level of charge injection. The body of the thesis consists of two papers, corresponding to (a) and (b) above. One of these has been already accepted for publication, while the other has been submitted for publication. Their preprints are enclosed at the end of the thesis.
Showing items related by title, author, creator and subject.
Material de empaque para biofiltración con base en poliuretano modificado con almidón, metodos para la manufactura del mismo y sistema de biofiltración OLGA BRIGIDA GUTIERREZ ACOSTA; VLADIMIR ALONSO ESCOBAR BARRIOS; SONIA LORENA ARRIAGA GARCIA
Preparación de materiales compuestos mediante la funcionalización covalente de nanotubos de carbono (CNTs) con polímero CLAUDIA GUADALUPE ESPINOSA GONZALEZ
Attachment of transition metal nanoparticles on nitrogen doped carbon nanotubes (MWNTs-CNx) and their further reactions. XAVIER NORBERTO LEPRÓ CHÁVEZ