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. 27, 2012
Filed:
Apr. 09, 2010
Geoffrey A. Cranch, Fairfax Station, VA (US);
Gordon M. H. Flockhart, Glasgow, GB;
Geoffrey A. Cranch, Fairfax Station, VA (US);
Gordon M. H. Flockhart, Glasgow, GB;
The United States of America as represented by the Secretary of the Navy, Washington, DC (US);
Abstract
An apparatus and method for characterizing the complex coupling coefficient of a multilayered periodic structure either during or after inscription is described. This apparatus is capable of continuously measuring the complex reflectivity at single or multiple wavelengths to a resolution limited by Rayleigh scattering in the waveguide section where the structure is inscribed. The apparatus is also capable of rejecting undesired signals associated with stray reflections in the system and unwanted environmentally induced change in optical path lengths during the inscription procedure. The complex coupling coefficient of the multilayered periodic structure can be derived from the measured complex reflectivity and can reveal errors present in the structure. The complex coupling coefficient can also be used to derive an error signal to enable implementation of a closed loop inscription system capable of inscribing error free multilayer structures.