| This work is a study of a practical Whispering Gallery Mode based sensing device that consists of optical polymer waveguides integrated with high Q Whispering Gallery Mode (WGM) resonators that is incorporated with microfluidics technology. We proposed, developed and experimental demonstrated a method that solves the issue of integrating high Q WGM resonators into practical sensors for real time and portable on field detection.;We demonstrated a novel implementation of a polymer optical waveguide coupled to the whispering gallery modes of a fused silica resonator disk. This is the first step in bringing high Q WGM disks closer to the integrated optics technology. We obtained near-critical coupling and a loaded Q = 1.2 x 107.;The use of a WGM resonator with an ultra-high quality factor Q is promising in highly sensitive, label-free, lab-on-a-chip sensor applications. However, one issue that causes the reduction of sensitivity and detection limits of the resonant sensor class is the fluctuation of temperature in the surrounding medium. We investigated a novel method of using the differential frequency of TE and TM modes to reduce the thermal noise baseline. Then, we studied the temperature dependence of the WGM based sensors and experimentally demonstrated the reduction of temperature fluctuation; and, thus, there was a significant improvement in the practical sensor detection limit. Consequently, the United States Patent 8,111,402 was granted for our novel invention.;In additional, the optical sensors are desirable to analyze small volumes or extremely dilute concentrations of analyte, thus we need an efficient method of delivering target molecules to the sensor's surface. Microfluidics and the concept of micro total analysis systems (&mgr;TAS) is a new and promising technology expected to revolutionize chemical and medical analysis systems. We theoretical analyzed and experimental demonstrated an integrating prototype of polymer waveguide-high Q WGM based sensor with the microfluidics technology. It is the critical step to bringing the prototype into a practical biosensor, which will lead to the ability to form a so-called lab-on-a-chip system. |
