Forming an optical grating with an apparatus providing an adjustable interference pattern

US10156680B2 · kind B2 · utility

Assignee

• National Research Council of Canada · CA

Inventors

• Dan Grobnic · Ottawa, CA
• Stephen J. Mihailov · Gatineau, CA
• Robert B. Walker · Paradise, US
• Ping Lu · Ottawa, CA
• Huimin Ding · Ottawa, CA
• David COULAS · Ottawa, CA

Key dates

• Filing date: Jul 10, 2015
• Grant date: Dec 18, 2018
• Expiry date: Jul 10, 2035

Classification

• Technology area (CPC G): Physics
• CPC primary: G02B2005/1804
• WIPO field: Optics
• WIPO sector: Instruments

Abstract

An apparatus for use with a pulsed laser source for forming an optical grating in a target includes an adjustable telescope having an element with a negative optical power, for generation of a diverging optical beam, so that the optical beam has adjustable divergence upon exiting the telescope while focusing of light inside the telescope is avoided. A transmission diffraction grating is disposed in the optical beam exiting the telescope, for forming an optical interference pattern on the target. Optical gratings with different grating periods may be formed by adjusting the divergence of the optical beam exiting the telescope. Lack of tight focal spots inside the telescope enables use of ultrashort pulse duration, high peak intensity laser sources.