is a side, cross-sectional view similar to FIG. 4, but with the optical fiber extended even further, to a position where its distal tip lies radially beyond the catheter outer wall, allowing a hole to be created that is larger than the catheter diameter. [0021]FIG. 6a and FIG. 6b are a side, cross-sectional view and an end view, respectively, of the distal end of a second embodiment of a catheter