An apparatus and method is disclosed for accurate, real time monitoring of the wavefront curvature of a coherent laser beam. Knowing the curvature, it can be quickly determined whether the laser beam is collimated, or focusing (converging), or de-focusing (diverging). The apparatus includes a lateral...http://www.google.ca/patents/US5042950?utm_source=gb-gplus-sharePatent US5042950 - Apparatus and method for laser beam diagnosis
