Method and apparatus for implementing a multi-channel tunable filter

US7483190B2 · kind B2 · utility

Assignee

• Ondax, Inc. · 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: Mar 8, 2006
• Grant date: Jan 27, 2009
• Expiry date: Mar 3, 2027

Classification

• Technology area (CPC G): Physics
• CPC primary: G03H2001/0268
• 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 or a continuously varying filter frequency imprinted into a filter material, such as Lithium Niobate or glass or polymer. 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.