Numerical modeling and ray tracing of SPatIal Frequency modulation for Imaging

Abstract

This thesis presents the first full geometric and physical optics characterization of aberrations and the performance of a simple system that implements SPatIal Frequency modulation for Imaging (SPIFI). SPIFI utilizes a chirped frequency mask that modulates the intensity of light along a single axis at a linear frequency sweep giving each lateral position a unique spatial frequency. By taking the Fourier transformation of the voltage verses time readout of a single element detector position data can be extracted for each point along the modulation axis. The geometric analysis is performed using Fraunhofer diffraction and conjugate imaging planes in a Fourier optics based approach. The ray tracing analysis is performed using the ZEMAX software for configurations involving achromatic lenses, flat field lenses, and a specialized lens array setup. Lastly, a unique SPIFI design setup is presented making use of a reflective scanned SPIFI mask to achieve random access imaging using three distinct spots for simultaneous imaging.