Browsing by Author "Erasmus, Anneke"
Now showing 1 - 1 of 1
Results Per Page
Sort Options
- ItemOptical tweezers for advanced microscopy(Stellenbosch : Stellenbosch University, 2018-03) Erasmus, Anneke; Rohwer, Erich G.; Neethling, Pieter H.; Bosman, Gurthwin W.; Stellenbosch University. Faculty of Science. Dept. of Physics.ENGLISH SUMMARY: The integration of lasers into microscopy has enabled new areas of research and expanded existing ones. Not only can one now image samples to resolutions and contrast unheard of before lasers became common, but one can now use lasers to exert minuscule forces on micron sized structures in your sample. This is achieved by creating a stable, single beam optical trap by tightly focusing a laser onto the sample containing micronsized particles submerged in a uid. Moving the trap position allows for the manipulation of micron-sized particles inside the sample. Such an optical trap is known as optical tweezers. In this work, optical tweezers are constructed and the trap is characterized by calibrating the picoNewton sized forces applied to micron-sized particles close to the trap centre. Applications of optical tweezers can be found in various aspects of biophotonics, some of which are discussed in this thesis. Using the constructed optical tweezers, the intracellular forces of molecular motors inside an onion cell were measured and the results are discussed. The optical tweezers setup can be expanded to include di erent imaging techniques. Two such imaging techniques, namely nonlinear microscopy and ptychography, a lensless imaging technique, are discussed in detail. Linear uorescence micrographs were taken with the setup to illustrate how such an integration would work. Ptychography was demonstrated in a separate imaging setup to illustrate the underlying principles. In this fashion, the individual components are investigated and evaluated separately, with the ultimate goal of incorporating all of these techniques in a truly multimodal microscopy platform.