Dynamics of Cross-Polarization Coupling in a Single Whispering-Gallery Microresonator

Abstract

In this dissertation, we investigate the dynamics of cross-polarization coupling (CPC) in a single whispering-gallery microresonator, both numerically and experimentally, and develop an independent method of estimating the CPC strength. First we introduce the basic properties of whispering-gallery modes (WGMs) in dielectric microresonators. Using WGM microresonators, we can observe classical analogs of the electromagnetically induced transparency (EIT) effects, both in coupled resonators and in a single resonator. Next, we focus on cross-polarization coupling (CPC) in a single microresonator. We analyze the dynamics of CPC using a ring cavity model and propose an independent way of estimating the CPC strength, which was previously found by fitting the experimental data to a computer model. Finally, we show experimental results of CMIT and ATS where the values of CPC strength are found by model fitting and by amplitude modulation. Then we compare the two values. Although we get both agreements and disagreements between the two methods, the results indicate that we have developed an independent method of estimating the CPC strength. We need to keep working and make full use of this independent way of estimating the coupling strength for optical signal processing and sensor applications of microresonators. We also need to identify the limitations of our new method.