Category: Thesis

(Predstavitev diplomskih nalog LEOSS)

Long active lenght microfluidic absorbance cell

Blaž

Tomaž Gregorec, 2022, master thesis, Summary: In the scope of this master’s thesis, the production of a system for off-axis laser splicing of silica capillaries and the production of a long active length absorption cell were covered. The capillary splicer enables the fabrication of special structures that offer new possibilities in the fabrication of optical fiber sensors. The absorption cell enables the measurement of light absorption in small volumes of liquids without the use of colorimetric reagents. The operation of the absorption cell was tested by measuring the ratio of isopropanol in water and by measuring the concentration of copper ions dissolved in water. Read More …

Femtosecond laser fabrication of microstructures

Blaž

Jure Javornik, 2022, Master thesis Abstract: In this master thesis a system for all-fiber micro-cell manufacturing is presented. System was built around an already existing fs laser system. Thesis describes an ultrashort pulse generation method and the theoretical background of ultrashort pulse and material intercation. A procedure for sensor manufacturing is presented. Sensor's spectral responses and mechanical propreties are presented. The fabrication of microfluidic channels, microscrews and microresonators on the tip of the optical fiber is described. The thesis also incorporates in-fiber mirror fabrication with ultrashort laser pulses inducing local refractive index changes. Mirror inscription took place at different pulse energy levels and in different configurations of mirror allignment. Optical and mechanical propreties of the inscribed mirrors were measured. Two application examples were shown using inscribed mirrors. Keywords: Ultrashort pulses, femtosecond laser, micro-structres, mirror inscription, micro-cell Read More …

Microfluidic flow sensor of dissolved oxygen in water

Blaž

Dominik Gril, 2022, Master thesis Abstaract: In this master thesis, we are presenting procedure designing and manufacturing of microfluidic optical sensor system, which is intended for measuring of dissolved oxygen in water. Sensor is based on luminescence quenching phenomena. We present a detailed design, and manufacturing procedure of microfluidic flow sensor system. System can perform measurements on low flows of sample, so it can perform measurement on small volume of liquid. There is also described designing analogue electronic circuit, for measuring short lifetimes of reagent. Presentation and evaluation of measurement results is also performed. Keywords: Microfluidics, Dissolved oxygen, Luminescence, Optical sensor Read More …