The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Mar. 10, 1992
Filed:
Jul. 17, 1990
Richard L Sandstrom, Encinitas, CA (US);
Cymer Laser Technologies, San Diego, CA (US);
Abstract
Monochromatic light from a laser gain generator passes through a first aperture to a beam expander which expands the beam width and reduces the angular divergence of the beam. The light from the beam expander has a curved wavefront because of (1) light diffraction in the aperture and (2) deviations from planar surfaces in the optical components in the light path. The light is then reflected by a first mirror to a grating which has a plurality of steps in a stepped configuration. The grating is adjustable curved so that the steps in the grating are parallel to the curved wavefront and so that light from only a particular band of wavelengths is reflected back to the first mirror. The light then passes back through the beam expander, which compresses the beam width, to the discharge chamber for further amplification. The light then passes through a second aperture to a partially reflecting mirror. A portion of the light is reflected by the partial mirror back to the discharge chamber for further amplification. The grating curvature is adjustable controlled by an apparatus which contacts the grating at three spaced points and which applies a controlled force to the grating along a line extending between one of the points and a position midway between the other two points. The grating curvature may be servoed to maintain the bandwidth of the laser light at a particular value as various components age.