Date of Award
Doctor of Philosophy (PhD)
Whispering gallery mode (WGM) microresonators have been studied for applications in many areas, such as sensing, lasing, and physical research, due to their high-quality factor and small mode volume. In this dissertation, I introduce two novel polymer silica hybrid microresonator device: a polymer coated microtoroid and a packaged microtoroid. These polymer silica hybrid devices exhibit several nonlinear effects including Raman lasing, the optical analog of electromagnetically-induced-transparency (EIT), and thermally induced non-reciprocity. Furthermore, several sensing applications based on packaged microtoroid resonator are demonstrated.
First, I highlight the packaged microtoroid resonator. Microresonators are commonly coupled with a tapered fiber, and the coupling is modulated by a 3D nanotranslation stage. The coupling condition is prone to instability, which means it is difficult to employ microresonators in practical applications. In this dissertation, I present several methods to utilize WGM microresonators for sensing applications.
In gas sensing, we have shown the microresonators are an optimal gas sensor due to their sensitivity, selectivity, and stability. In magnetic field sensing, we demonstrate a compact and robust magnetometer with a high sensitivity of 880 pT/Hz1/2 and a 4-decade dynamic range. Moreover, we have also successfully applied microresonators in acoustic sensing and imaging. Our device has achieved much higher sensitivity than reported commercial acoustic micro sensors. These results open the way for using portable, robust, and stable WGM microlasers and sensors for applications in various environments.
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