Abstract: Material is laser milled by generating a series of laser pulses, each pulse possessing a main portion and a tail, and preventing the energy in one or more portions of the pulse, from striking the material being processed. In one embodiment this is done by terminating the pulse before a portion of the tail is generated, thereby to reduce thermal stress and leave smooth edges on the laser-milled material.

Abstract: An expandable stent has a porous tubular wall with a longitudinal axis. The porous tubular wall has a plurality of butterfly cells disposed in a direction orthogonal to the longitudinal axis of the tubular wall, each butterfly cell having two symmetrical wing portions, an abdomen portion, and an antenna portion. The abdomen portion and the antenna portion have different shapes. Preferably, each cell includes a plurality of curved portions and no straight portions. Also, the cells of one row of cells are preferably interlocked with the cells of an adjacent row of cells, each cell having at least six three-point connections. Preferably, each cell has substantially the same shape.