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Abstract This thesis aims to study and develop polarized spectrometers based on Mi-chelson interferometer. The use of polarized spectrometers is advantageous as they detect more sample features. Polarized FTIR spectroscopy separates the information related to the physical and chemical nature of the sample, thus measures absorbance in highly scattering materials, valuable in biomedical, agricultural, and environmental monitoring. For polymer quality control, it optimizes mechanical properties. NIR spec-troscopy, common in various industries and biomedical fields, is rapid and non-invasive, aiding in glucose sensing and muscle observation. Recent miniaturization al-lows portable testing in fields like soil and feed analysis. Portable spectrometers offer real-time feedback in production, aiding in temperature control and knowing polymer stretching direction. Our thesis aims to explore novel polarized spectrometers based on MEMS technology. We focus on studying polarized light interferometers, Fourier op-tics models, scattering in turbid media, and Mueller matrix patterns for diverse appli-cations. The thesis is organized into six chapters as listed below: Chapter 1: gives a brief introduction of the motivation, objectives, major contribu-tions, and organization of the thesis. Chapter 2: introduces the light propagation theory and the wave equations, discussing the polarization types and the parameters of the polarization ellipse. Jones and Mueller matrices are discussed and the meaning of Mueller elements for material is described. The optical FTIR spectrometer is discussed. The Mueller matrix can be measured by different states of polarization using Cramer’s rule. The method of measuring Mueller matrix is investigated by measuring the linear polarizer Mueller matrix. Finally, a brief comparison of the polarized spectrometer applications and benefits is presented. Chapter 3: presents a polarization spectrometer model, discusses the s and p polariza-tion at Air silicon interface and beam splitter output in a simple Michelson configuration versus incidence angle. The system of polarized light FTIR spectrometer based on Mi-chelson interferometers is analyzed by studying in details the overall transfer function and the generated interferogram, studying the effect of beam waists, incidence angle, wavelength for TE and TM and unpolarized input light. The enhanced Michelson inter-ferometer design is simulated and demonstrating by measurement. The spectrometer Mueller elements are calculated and measured. The sample effect can be extracted without the spectrometer effect by calibrating the spectrometer and remove its Mueller matrix. Chapter 4: introduces a single scattering model for any turbid medium, applying it on two interesting applications; measuring direction of director liquid crystal and, meas-uring glucose dissolved in water and extracting the glucose concentration directly from rotation pattern of Mueller matrix. Finally, we study the Mueller pattern for double and triple scattering in turbid media. Chapter 5: introduces experimental results for two applications; scattering particles and polymer orientation. First a polarized scattered light Fourier transform infrared (FTIR) spectroscopy technique is discussed to enhance measurements through distinct layers of low and multi-scattering materials. This technique was validated by measur-ing various samples of multi-scattering powder in plastic bags, demonstrating the abil-ity to separate the powder spectrum from the plastic bag spectra. Second, using polar-ized MEMS FTIR spectroscopy for orientation monitoring of polymer for quality con-trol was discussed. A 1mm thick commercial plastic is measured in a transmission mode. Polar diagrams extracted the plastic sleeve’s orientation angle, showing a slight rotation compared to a reference direction set for the linear polarizer. Bench-top de-vice measurements were performed for comparison, demonstrating good agreement. Chapter 6: gives the conclusions of this thesis and introduces several recommenda-tions and suggestions for future work. |