KINOFORM-ONLY GAUSSIAN-TO-RECTANGLE BEAM SHAPER FOR A SEMICONDUCTOR-LASER

A kinoform that shapes the divergent beam from a semiconductor laser w ithout using any other optical components was designed and fabricated. The kinoform-only concept means that the kinoform must perform both t he actual beam shaping as well as focusing the divergent laser beam, c orrecting for the astigmatism of the laser, and correcting for the sph erical aberration of the laser exit window. A rectangular beam of dime nsions 1000 mu m X 300 mu m is formed 42 mm behind the kinoform. Of th e total output from the laser, some 50% is incident upon the kinoform, of which similar to 50% will appear in the rectangular beam. The inte nsity uniformity error within the rectangle increases from the design value of 8% to 38% because of sensitivity to fabrication errors. The k inoform-only design for beam-shaping applications requires high manufa cturing accuracy but is attractive because a system using such a compo nent is easily mounted and aligned and, with the use of kinoform-repli cation techniques, can be mass produced at low cost. (C) 1996 Optical Society of America