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内蒙古自治区呼和浩特市赛罕区大学西街235号 邮编: 010021
作者单位:Universidade Estadual de Campinas
授予年度:1000年
摘 要:The interaction between light and matter occurs due to electric polarization which can be described as a power series of the electric field. A light source sufficiently intense can access high order terms leading to nonlinear phenomena, such as third harmonic generation which recombine three photons in a new one with higher energy. To reach the necessary condition of intensity, we will use the resonant intensification obtained with optical microcavities which can confine thousands of Watts of circulating power in a micrometric volume. Besides the power intensification, the design of the microcavities that we studied has the potential to integration and mass production and enable a mode engineering in order to optimize the couple both between the modes and the source. In this dissertation, we studied silicon dioxide microcavities which present as first nonlinear term the third order term. We start describing the mode theory for couplesd mode due to third order nonlinearity, identifying the parameters that optimize the photon conversion from the infrared mode to the visible mode. The proposed model takes into account the phase-mismatch induced by dispersion, phase-modulation effects and bistability. We propose a technique to compensate the phase-shift and describe the system in phase-matching condition. In the following, we present the experiments done in order to compare the theoretical and experimental results. Although we couldnt reach the maximum photon conversion efficiency regime due to limitation in maximum input power, is possible to identify the effectiveness of the phase-matching method. Meanwhile, we studied the fabrication process to characterize the current method employed by the research group and it was possible to identify deficit and limitation that may be compromising the fabrication result