FIBEROPTIC BEAM DELIVERY SYSTEMS FOR PARTICLE IMAGE VELOCIMETRY

The role of fibre-optics in the formation of light sheets for particle image velocimetry is reviewed, concentrating on the power handling ca pacities of fibres and their effect on laser beam quality. It is shown that when continuous wave lasers are used, chopped to form a pulsed l ight sheet, then it is feasible to rise a single multimode optical fib re to deliver the beam. Conversely, with Q-switched lasers, the peak p ower densities are so high that to achieve an adequate compromise betw een pulse energy and beam quality, delivery systems based on bundles o f multimode fibres have been developed. (C) 1997 Elsevier Science Ltd.