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:
Nov. 04, 2003
Filed:
Aug. 14, 2001
William Gong, Sunnyvale, CA (US);
Richard Tella, Sunnyvale, CA (US);
Glenn Rankin, Menlo Park, CA (US);
Agilent Technologies, Inc., Palo Alto, CA (US);
Abstract
The split-beam optical thickness gauge (OTG) measures the height difference of two adjacent surfaces. Low-coherence light is generated by the low-coherence light source. The split-beam probe head receives the low-coherence light and splits the incoming low-coherence light into a primary beam and walk-off beam. The primary beam shines upon a first surface and is reflected back up into the split-beam probe head. The walk-off beam shines upon a second surface and is reflected back up into the split-beam probe head. Spatial separation between the primary beam and the walk-off beam ensures that each beam shines substantially on only one of the surfaces. An incorporated polarizer assures that the primary and walk-off beams interfere. The reflected light returns to the autocorrelator and is detected so that distance measurements can be determined based upon a change in the path difference between the reflected primary beam and the walk-off beam.