Patent Number: 8,878,095

Title: Reducing back-reflection in laser micromachining systems

Abstract: Systems and methods reduce or prevent back-reflections in a laser processing system. A system includes a laser source to generate an incident laser beam, a laser beam output to direct the incident laser beam toward a work surface along a beam path, and a spatial filter. The system further includes a beam expander to expand a diameter of the incident laser beam received through the spatial filter, and a scan lens to focus the expanded incident laser beam at a target location on a work surface. A reflected laser beam from the work surface returns through the scan lens to the beam expander, which reduces a diameter of the reflected beam and increases a divergence angle of the reflected laser beam. The spatial filter blocks a portion of the diverging reflected laser beam from passing through the aperture and returning to the laser beam output.

Inventors: Li; Guangyu (Portland, OR), Alpay; Mehmet E. (Portland, OR)

Assignee: Electro Scientific Industries, Inc.

International Classification: B23K 26/06 (20140101); B23K 26/08 (20140101)

Expiration Date: 2019-11-04 0:00:00