Patent ID: 7423818

Claim:
A method of suppressing distortion of a working laser beam directed for incidence on a target specimen presented for processing by a laser link processing system, the working laser beam derived from a laser output beam propagating from a laser and attenuated by an attenuator, both of which forming parts of the laser link processing system, the distortion of the working laser beam generally increasing in predominance in response to increasing amounts of attenuation of the laser output beam, comprising: directing the laser output beam through the attenuator to form an attenuator output beam; providing a spatial filter including a focus lens and an aperture; directing the attenuator output beam to the focus lens to form a focused beam at a focal region associated with the focus lens, the focused beam including a primary beam component and a stray light component, the stray light component resulting from link processing system scattered light combining with the attenuator output beam, and the primary beam component focusing to a spatial frequency and the stray light component focusing to a spatial frequency higher than the spatial frequency of the primary beam component; and positioning the aperture at or near the focal region to allow the primary beam component to pass unobstructed and to block the stray light components, thereby to remove stray light-induced distortion from the working laser beam.