SPOT SIZE-REDUCTION IN COUPLING OF LASER TO MICROMANIPULATOR IN LASERMICROSURGERY BY FIBEROPTIC LINK

Background and Objective: In coupling laser with micromanipulator thro ugh fiberoptics, the resulting diameter of the spot is limited by the laws of geometrical optics, because of the high numerical aperture (N. A.) of fiberoptic radiation. A new method for the reduction of spot si ze diameter is suggested. Study Design/Materials and Methods: The outp ut of a 2 mW He-Ne laser was couped via fiberoptic link, the fiberopti c output light collected by a single lens collimator and directed to t he input of the micromanipulator. Results: The spot size can be consid erably reduced by the introduction of an aperture which reduces the nu merical aperture (N.A.) of the fiberoptic. The resulting reduction in total power has Little effect on the power density. Conclusion: This a pproach to the collimator design permits reduction in spot size withou t any significant changes in power density, thus avoiding damage to th e tissue and obtaining optimum performance from the micromanipulator. (C) 1995 Wiley-Liss, Inc.