A system includes a laser catheter and a rotating optical member to receive a laser beam along an optical path and rotate to a selected position to redirect the laser beam from the optical path onto one or more selected optical fibers of a laser catheter, wherein a distal end of the laser catheter irradiates an endovascular structure. Also provided is a microprocessor executable controller configured, to select at least one of a fiber active area for each optical channel, a number of optical channels, a configuration of fibers in an optical channel, an optical channel to be irradiated, and an ordering of optical channel irradiation.