Super-gain parametric wave amplification in optical micro-resonators using ultrashort pump waves

Thesis Type: Doctorate

Institution Of The Thesis: Middle East Technical University, Faculty of Engineering, Department of Electrical and Electronics Engineering, Turkey

Approval Date: 2020

Student: Özüm Emre Aşırım



The aim of this thesis is to show that super-gain electromagnetic wave amplification can be achieved in a small micro-resonator using high-intensity ultrashort pump waves, provided that the frequencies of the ultrashort pulses are tuned to maximize the intracavity magnitude of the wave to be amplified, which is called the stimulus wave. In order to accomplish this, a dispersion analysis is performed via numerical modeling of the polarization density in terms of the nonlinear electron cloud motion. The polarization density is then concurrently solved with the wave equation for the electric field. Through a series of nonlinear programming integrated finite difference time domain simulations, we have determined the optimum pump wave frequencies that simultaneously maximize the stored electric energy density and the polarization density inside a micro-resonator by using the Broyden-Fletcher-Goldfarb-Shanno (BFGS) optimization algorithm. Based on the results of our numerical experiments, we propose that micrometer-scale achievement of super-gain electromagnetic wave amplification is possible in a micro-resonator with high-intensity ultrashort “pump wave” pulses, by determining the optimum frequencies that concurrently maximize the stored electric energy density and the polarization density in a dielectric interaction medium.