الفهرس | Only 14 pages are availabe for public view |
Abstract This thesis aims to study and develop MEMS spectrometers based on Fabry-Perot (FP) interferometers and electrostatic actuators. For this purpose, we developed high speed electrostatic actuators and compared between different architectures. A novel Fourier Transform InfraRed (FT-IR) spectrometer architecture based on cascaded FP interferometers was introduced and analyzed thoroughly. Two designs for the cas-caded FP FT-IR spectrometers based on Deep-Reactive-Ion-Etching (DRIE) technol-ogy over Silicon-On-Insulator (SOI) wafer were proposed and implemented. Success-ful demonstration of the spectrometer based the proposed designs was realized. The proposed MEMS spectrometer has the advantage of ultra-compact optics and high resolving power compared to the conventional architecture. The thesis is divided into six chapters as listed below: Chapter 1: gives a brief introduction of the motivation, objectives, major contributions and organization of the thesis. Chapter 2: introduces a review on the types of optical spectrometer, namely, diffrac-tion grating, tunable filter and FTIR spectrometers. An overview on the MEMS tech-nology and the electrostatic actuation is briefly given. The FT-IR spectrometer theory of operation and the main system specifications are discussed. Finally, a brief compar-ison of the state-of-the-art miniaturized spectrometer is presented. Chapter 3: reports the design, fabrication and characterization of high-speed MEMS actuators with in-plane motion; achieving the highest product of the travel range and frequency under atmospheric pressure. Two actuators are reported having resonance frequencies of about 26.1 kHz and 93.5 kHz and achieving a single-side travel range of about 9.1 µm and 2 µm. An opto-mechanical characterization method is applied accounting for the diffraction effect in the microscale. The experimental results are compared to the theoretical analysis. Chapter 4: introduces and analyzes the system of FTIR spectrometer based on cascad-ed interferometers. The system is analyzed for different combinations of interferome-ters by studying in details the overall transfer function and the generated interfero-gram and the corresponding spectrum. Two architectures based on FP interferometers are studied and optimization study for the different design parameter is carried out. Chapter 5: presents two designs of the FP-FTIR spectrometer. The designs are mod-eled using Fourier optics to account for the diffraction effect. The implementation of the designs using DRIE technology on SOI is explained. Finally, the experimental re-sults of the developed spectrometer are presented, demonstrating the success of the ultra-compact optics and the high resolving power compared to the conventional archi-tecture. Chapter 6: gives the conclusion of this thesis and introduces several recommendations and suggestions for the future work. Key words: Fabry-Perot interferometer, Micro-electro-mechanical systems (MEMS) technology, High speed actuators, Fourier transform spectroscopy, Dispersion, Micro-optical bench technology, Near-infrared (NIR) spectrometer, Fourier optics. |