Date of Graduation

7-2015

Document Type

Thesis

Degree Name

Master of Science in Microelectronics-Photonics (MS)

Degree Level

Graduate

Department

Graduate School

Advisor

Magda El-Shenawee

Committee Member

Mark E. Arnold

Second Committee Member

Baohua Li

Third Committee Member

Rick Wise

Abstract

This thesis presents numerical simulation of terahertz (THz) wave interaction with breast cancer tumor tissue sections. The obtained results are expressed in THz images of heterogeneous material that mimics the excised breast cancer tissue sections. The finite-element software package ANSYS High Frequency Structural Simulator (HFSS) was used in this work. HFSS is a full wave frequency domain three-dimensional (3D) electromagnetic simulation package. In this work, four breast cancer tissue models based on pathology images were simulated and images of the models were obtained at 1 THz. An incident Gaussian beam was raster scanned over tissue model configurations and the reflected electric fields were calculated at a grid of pixels to create the images in the far and near field zones. Several parameters that influenced the accuracy of the obtained THz images were investigated. The step size used of scanning the incident Gaussian beam over the tissue model configurations was investigated. The results showed that scanning the Gaussian beam in 100 µm steps provided better images of the tissue models compared with the 200 µm step size. The simulated tissue thicknesses of 10 µm and 40 µm were investigated here to understand the challenges faced in the THz experimental results, conducted by others in the research group. The obtained results of 40 µm thick tissue model demonstrated better differentiation of the heterogeneous regions of the tissue model compared with the 10 µm thickness, which was consistent with the trend observed in the experimental results. Additional results simulating the THz camera, i.e. using a single incident Gaussians beam that illuminates the whole tissue section without raster scanning, were investigated. All simulated THz images obtained in this work are consistent with the pathology images. The results of this work helped understand the interaction of THz waves with relatively thin sections of ex vivo breast cancer tissues.

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