Method and apparatus for implementing a multi-channel tunable filter

US6829067B2 · kind B2 · utility

Assignee

• CALIFORNIA INSTITUTE OF TECHNOLOGY · US

Inventors

• Demetri Psaltis · Altadena, US
• Christophe Moser · Pasadena, US
• Greg Steckman · Pasadena, US
• Karsten Buse · Bonn, DE
• Ingo Nee · Papenburg, DE
• Joerg Hukriede · Lengerich, DE

Key dates

• Filing date: Dec 4, 2001
• Grant date: Dec 7, 2004
• Expiry date: Mar 13, 2022

Classification

• Technology area (CPC G): Physics
• CPC primary: G03H2260/54
• WIPO field: Optics
• WIPO sector: Instruments

Abstract

The present invention provides a multi-channel tunable filter and methods for making such a filter. In one embodiment, the filter comprises a bank of gratings imprinted into a filter material, such as Lithium Niobate. In another embodiment, the filter comprises a bank of gratings imprinted on a thin-film filter. An optical read-head comprising a pair of lenses is configured to pass light from within an optical fiber carrying multiple wavelengths through an appropriate grating to extract or drop a specific wavelength. To ensure continuous data transmission, the filter is tuned to a wavelength by configuring the read-head to move in a hitless manner. In one embodiment, the gratings are recorded by the interference of two beams. A first plane wave reflects off a first mirror stack and a second plane wave reflects off a second mirror stack. In another embodiment, the gratings are recorded by a phase masking method.