טכניון מכון טכנולוגי לישראל
הטכניון מכון טכנולוגי לישראל - בית הספר ללימודי מוסמכים  
M.Sc Thesis
M.Sc StudentRabi Yaron
SubjectNovel Optical Imaging Techniques Using a Directional
Detector and Doppler Effect
DepartmentDepartment of Electrical Engineering
Supervisor Professor Moshe Horowitz


Abstract

In this work we demonstrate two novel imaging techniques. The first technique is based on a directional detector. The output of the directional detector is affected only by light beams that propagate in a narrow angular window around a predefined direction. A light beam that propagates in another direction does not significantly affect the output of the detector. The directional detector is implemented using an interference effect and a finite width detector. The coherent detection used in the setup also enables to detect weak reflections from the object. The directional detector was analyzed theoretically and demonstrated experimentally. A reduced model was developed in order to estimate dependence of the system angular resolution on its parameters. A directional detectors array enables to reduce the effect of diffraction and scattering, and hence reconstruction techniques based on non-diffracting sources may be implemented. The second imaging technique we demonstrated theoretically is called Doppler imaging. We assume that the object contains several scatterers. The object is mounted on a rotary stage and it is illuminated by a monochromatic light. Due to Doppler effect, scatterers at different locations have a different Doppler shift. Due to the stage rotation, the Doppler shift of the reflected light changes in time. We apply the Gabor transform to obtain a time-frequency map of the detected signal. The result of the Gabor transform is used to reconstruct the object profile.