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:
Apr. 15, 2008
Filed:
Apr. 12, 2006
Gregory J. Steckman, Glendora, CA (US);
Frank Havermeyer, Arcadia, CA (US);
Lawrence Pokwah Ho, Arcadia, CA (US);
Gregory J. Steckman, Glendora, CA (US);
Frank Havermeyer, Arcadia, CA (US);
Lawrence Pokwah Ho, Arcadia, CA (US);
Ondax, Inc., Monrovia, CA (US);
Abstract
The invention describes a system for the measurement of volume holograms on a wafer scale that permits high-resolution and high throughput measurement of grating parameters. The invention uses a collimated beam of a fixed wavelength light source that is transmitted through the wafer to be tested. The transmitted beam is imaged with a lens onto a sensor. The sensor is used to measure the beam power under a variety of conditions, including without a wafer in place, so that the various measurements can be used to determine grating characteristics. The measurement data produced includes values for grating spacing, tilt angle, and diffraction efficiency with a high spatial resolution.