Patent ID: 7443587
Filing Date: 2008-10-28
Classification: G02B

Abstract:
1. A laser beam production module for producing a laser beam having a desired beam aspect-ratio, a minimized or reduced to zero beam dispersion, and corrected astigmatism, said laser beam producing module comprising: a module housing; a visible laser diode (VLD), mounted within said module housing, for producing a laser beam from its junction having divergent and elliptical beam characteristics; a collimating lens (L a first fixed spatial-frequency diffractive optical element (DOE), mounted in said module housing, having a beam expansion factor M a second fixed spatial-frequency diffractive optical element (DOE), mounted in said module housing, having a beam expansion factor M wherein the collimated laser beam exiting said collimating lens L (a) the collimating lens has a downstream focus location, in the direction of said collimating lens L (b) for the calculated downstream focus location, D is selected to provide a desired beam spot size, thereby determining an upstream focus location for the lens, in the direction of said VLD; and (d) the focal length of the collimating lens is selected according to the upstream and downstream focus locations, whereby the collimated laser beam exiting said second DOE exits has a controlled beam aspect-ratio, a minimized or reduced to zero beam dispersion, and corrected astigmatism; and wherein said laser beam is transmitted through said collimating lens L