【作者】 赵辉；

【导师】 丁迎春；

【作者基本信息】 北京化工大学 ， 凝聚态物理， 2009， 硕士

【摘要】 本文研究的是一种由一系列高品质因子微腔所构成的光波导—耦合谐振腔光波导。与其他类型的光波导不同,耦合谐振腔光波导(CROW)是通过相对独立的光学微腔之间的弱耦合所构成的。目前已在环形腔、FP腔、光子晶体缺陷腔中得以实现。耦合谐振腔光波导(CROW)能够被应用在光存储,干涉仪,光开关,光学滤波器、密集波分复用等多个领域。其主要性能参数:色散关系、群速度、通带带宽、存储容量等,以及透射光谱特性:最大平坦带宽、输出功率、禁带宽度、带阻特性、透射率等,都会对其在实际应用中的价值造成很大的影响。应用紧束缚理论,来分析相邻微腔之间的耦合率对CROW性能参数的影响。结果表明,CROW的延迟时间、存储容量随着耦合率的增大而降低,而色散、群速度随着耦合率的增大而增大。利用传输矩阵的方法,推导出CROW的传输函数公式。模拟了微腔个数、耦合率、有效折射率、微腔半径、衰减因子不同的情况下,CROW的透射光谱特性。通过对比,讨论各个参数对其通带带宽、通带平坦性、带阻特性、禁带宽度的影响。找到改善其传输特性的方法,达到改善其输出光谱特性的目的。对于以高色散介质(三能级系统EIT)为背景的光子晶体缺陷CROW进行了理论分析。通过对比不同控制域Rabi频率下光子晶体缺陷CROW的光学性质。发现,由光子晶体缺陷构成的相邻谐振腔之间的耦合率,随着背景介质色散的增强而减小。而色散关系与背景介质的控制域Rabi频率有着密切的联系。随着Rabi频率的减小,耦合率也会减小,这就会使光波在波导中传播的群速度降低。另外,由于Rabi频率的减小,光子晶体缺陷CROW的通带带宽也会减小。但Rabi频率的减小会造成品质因子的降低。通过在一定范围内改变三能级EIT介质的控制域Rabi频率,我们可以可控的调整光子晶体缺陷CROW的群速度及通带带宽,进而达到控制其延迟时间及存储容量的目的。更多还原

【Abstract】 We study a new type of optical waveguide that consists of a sequence of coupled high-Q resonators—coupled resonator optical waveguide. Unlike other types of optical waveguide, waveguiding in the coupled resonator optical waveguide (CROW) is achieved through weak coupling between otherwise localized high-Q optical cavities. CROW mainly composed of ring resonators ,photonic crystal defect cavities and Fabyr -Paort cavities.CROW can find applications such as optical buffer, optical switch, optical filter,interferometer and DWDM. It’s Performance parameters: dispersive relationship, group velocity, pass bandwidth, storage capability and the performance of output spectral will impact it application value. Based on tight-binding theory, we show that the group velocity, delay time and storage capacity of coupled resonator optical waveguide(CROW) strongly depends on the coupled ratio. The result is the delay time and storage capacity attenuates as the coupled ratio increased. And the group velocity and dispersion relation became large as the coupled ratio increased. Using the transfer matrix, we analyzed the influences of the coupling coefficients between micro-ring, the loss in the micro-ring and the radius of micro-ring on spectral response in the micro-ring resonator, which are relate with performance of output spectral. So as to improve the performance of output spectral response.Analysis of photonic crystal coupled resonator optical waveguide (CROW) structures with a highly dispersive (three-level EIT) background medium is presented. We can transform the ptical properties of CROW by control the control field Rabi frequency. We find that the coupling strength between nearest neighbor cavities in the CROW decreases with increasing steepness of the background dispersion, which is continuously tunable as it is directly related to the control field Rabi frequency. The weaker coupling decreases the speed of pulse propagation through the waveguide. In addition, due to decrease of the control field Rabi frequency , the bands become flatter and the absorption of the EIT media would reduce the Q-factor of the cavities. We can control the Bandwidth , delay time, Storage capacity of photonic crystal coupled resonator optical waveguide by transform the control field Rabi frequency of three-level EIT media.更多还原