Abstract: The invention relates to a beam shaping system for providing a square or rectangular laser beam having a controlled intensity profile (uniform, super gaussian or cosine corrected for example) from an incident non-uniform beam intensity profile laser beam source (a Gaussian profile, a profile with astigmatism or any non-rotationally symmetric and non-uniform profile for example). The beam shaping system uses a first acylindrical lens for shaping the incident laser beam along a first axis and a second acylindrical lens orthogonally disposed relative to the first acylindrical lens and for shaping the incident beam along a second axis. The thereby provided light beam is a rectangular beam having a controlled intensity distribution in the far field.

Abstract: A phase mask (15) for modulating a collimated light beam passing therethrough, the light beam being diffracted to photoinduce a refractive index profile in a photosensitive optical medium, the phase mask (15) comprises a substrate (17) having an outer surface provided with a plurality of parallel grating corrugations (19). The grating corrugations (19) have a non-uniform relief depth across the outer surface for photoinducing a non-uniform refractive index profile in the photosensitive optical medium. The non-uniform relief depth is defined by a variable thin film layer (21) of variable thickness overlaying the substrate (17). The grating corrugations (19) can either be etched into the variable thin film layer (21) itself or be etched into the substrate (17), with the variable this film layer (21) being deposited on it after etching. Methods to make such phase masks are also provided.