الفهرس 
The FTIR SpectrometerOnly 14 pages are availabe for public view
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Abstract
The objective of this thesis is to study the pulsed operation of MEMS interferometers when excited by discrete light pulses. This is helpful in some applications such as non-linear spectroscopy and spectroscopic measurements based on a supercontinuum laser source. This helps to understand the limitations and requirements to obtain a correct distortion-free spectrum for different applications. First, a theoretical model is developed to study the effect of repetition rate and duty cycle on the spectrum obtained by the MEMS-based FTIR spectrometer. Experimental measurements are also conducted to measure the signal-to-noise ratio, as well as spectral distortion at different values of repetition rate and duty cycle. The experimental results are conducted using multiple pulsed light sources including a white light source modulated using an optical chopper, and an amplified spontaneous emission source modulated using an acousto-optic modulator. Experimental results are also obtained using a Q-switched supercontinuum laser source, which has a wide wavelength range but the signal-to-noise ratio is limited due to fluctuations of the energy-per-pulse. Also, this source has a limited repetition rate of 20kHz, which requires some modifications in the spectrometer signal processing. Additionally, a supercontinuum source based on a passively mode-locked laser is built; it has the advantage of a relatively high repetition rate of 16.5MHz, but it has a limited wavelength range of about 200 nm. We use the MEMS FTIR spectrometer to carry out spectroscopic measurements for carbon dioxide gas with different concentrations using this latter source. Finally, we propose the use of the MEMS-based Michelson interferometer in implementing an optical autocorrelator with a scanning range of 1.2 ps by exploiting the two-photon absorption process in a silicon photodetector. Several optical pulses are measured using the autocorrelator and they showed good agreement with the measurements of a commercial bulky optical autocorrelator.