This thesis describes my work on the development of optical trappingtechniques for manipulating airborne particles. Although many of the basicprinciples are similar to those used in more conventional colloidal experiments,there are many differences which have been described and investigated indetail in this work.Basic characterisation measurements are made, such as axial Q and sample sizeselectivity, for a number of sample liquids in a basic optical tweezers setup.Performance at 532nm and 1064nm were compared and shown to be verysimilar, despite increased absorption in the infrared. A successful method wasdeveloped for the optical trapping of solid aerosol particles, allowing a directcomparison between similar particles suspended in both the gas and liquidphase.A single beam levitation trap was developed for transporting liquid aerosols toallow multiple chemical measurements to be made on a single droplet.Performance between Gaussian and Bessel beams was compared for variousliquids, with guiding distances of several millimetres being achieved with theBessel beam geometry.An experiment to demonstrate lasing within an optically tweezed droplet wasalso performed and spectra were taken. Although strong resonance modeswere evident, the data was not conclusive. However, it is likely that a redesignof the experiment would be successful.These techniques have extended research capabilities in the areas of bothoptical trapping and atmospheric chemistry, allowing the detailed study ofsingle aerosol particles in the 1-10 μm range.
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