Abstract: An optical fiber coupling system is described including a laser for generating a laser beam through a lens having spherical aberration. The spherical aberration in the lens blurs the focal spot, thereby reducing incident fluence levels over the prior art configurations. To further reduce peak fluence levels, a small obscuration is placed between the laser beam and the lens near the center of the lens. The incident end of the optical fiber is then placed at the point where the cross sectional area of the laser beam is smallest, which is closer to the lens than both the location of peak fluence and the paraxial focal point.