POSTER SESSION 1
The filter is a grounded coplanarwaveguide structure which has 2.4mm by 2.4mm dimension with center frequency at 10GHz, thebandwidth is 0.4GHz, the insertion loss is 1.7dB and the quality factor is 25.
Building and Testing of an Adaptive Optics System for Optical Microscopy Presenter(s): Zhenyu Yang Advisor(s): Qiwen Zhan Electro-Optics Graduate Program - Graduate Research
Adaptive optics (AO), as the technology of compensating the wavefront distortion can significantly improve the performance of existing optical systems. An adaptive optics system is used to correct the wavefront distortion caused by the imperfection of optical elements and environment. It was originally developed for military and astronomy applications to mitigate the adverse effect of wavefront distortions caused by Earth창s atmosphere turbulence. With a closed-loop AO system, distortions caused by the environment can be reduced dramatically. As the technology matures, AO systems can be integrated into a wide variety of optical systems to improve their performance. The goal of this project is to build such an AO system which can be integrated into high-resolution optical microscopy. A Thorlabs Adaptive Optics Kit was set up. A Shack-Hartmann Wavefront sensor, a Deformable Mirror and other necessary optics hardware was combined together on a breadboard, and the control software was also implemented to form the feedback loop.
Experimental Confirmation of Strong Fluorescence Enhancement Using One-dimensional GaP/SiO2 Photonic Band Gap Structure Presenter(s): Jian Gao Advisor(s): Andrew M Sarangan, Qiwen Zhan Electro-Optics Graduate Program - Graduate Research
We report the experimental confirmation of the fluorescence enhancement effect using a one-dimensional photonic band gap (1D PBG) structure. This 1D PBG structure consists of periodic multilayer thin films with gallium phosphide (GaP) and silicon dioxide (SiO2) as the alternating high and low index materials. Strong evanescent field enhancement can be generated at the last interface due to the combination of total internal reflection and photonic crystal resonance for the excitation wavelength. In addition, the 1D PBG structure is designed as an omnidirectional reflector for the red-shifted fluorescent signal emitted from the surface bounded molecules. This omnidirectional reflection function helps to improve the collection efficiency of the objective lens and further increase the detected fluorescent signal. Compared with the commonly used bare glass substrate, an average enhancement factor of 69 times has been experimentally verified with quantum dots as the fluorescent markers. This fluorescence enhancer may find broad applications in single molecular optical sensing and imaging.
Metal Nanorod Structures: Electromagnetic and quantum confinement properties Presenter(s): Li Li Advisor(s): Joseph W Haus Electro-Optics Graduate Program - Graduate Research
The purpose of this work is to understand electromagnetic plasmonic response and electron quantum confinement in an ellipsoidal metallic nanorod. The plasmon resonance of metallic nanorods displays geometric tunability controlled by the ratio of its minor to major axes. The surface plasmon resonance (SPR) of metallic nanorods (Ag, Au, Cu) based on Mie theory is studied for different geometries and physical environments. Moreover, we calculate the electron density of states for the nanowire geometry. Combining the density of state with the Fermi-Dirac distribution produces very sharp electron energy distribution. We present theoretical results based on SPR theory and the electron density of states. Our results are a first step in understanding more complex metal-insulator-metal structures for energy harvesting applications.
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