This work focuses on measurements of refractive index changes due to temperature shifts of the medium, which occur because of particles absorbing light. The main motivation for the master’s thesis is measuring the concentration of black carbon particles and other aerosols. The same approach can also be used with other media, such as water. In the thesis we designed an experimental optical-fiber Mach-Zehnder interferometer. We have shown that it can be used to detect changes of the optical path, which can happen due to temperature shifts. We improved the setup by adding an additional pump laser, with which we heat the water in the measuring branch of the interferometer. With this improvement we have shown that we are able to detect changes in the refractive index of the water, which happen because of temperature shifts.
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