Photosensitive optical waveguide

US7389022B2 · kind B2 · utility

Assignee

• ALCATEL · FR

Inventors

• Carlos De Barros · Boulogne-Billancourt, FR
• Lionel Provost · Marcoussis, FR
• Hélène Biscaras · Voisins-le-Bretonneux, FR
• Christine Moreau · Palaiseau, FR

Key dates

• Filing date: Dec 1, 2004
• Grant date: Jun 17, 2008
• Expiry date: Dec 1, 2024

Classification

• Technology area (CPC G): Physics
• CPC primary: G02B6/02119
• WIPO field: Optics
• WIPO sector: Instruments

Abstract

An optical waveguide suitable for a slanted Bragg grating (SBG) to be written thereinto has a refractive index profile defining a core and a cladding and a specific photosensitivity profile. This photosensitivity profile W(r) is such that, for a given SBG writing angle θ, the coupling of the fundamental mode into itself as counterpropagation in the waveguide, K(θ), is substantially zero and such that its derivative K′(θ) with respect to the angle θ is also substantially equal to zero. The zero derivative, and also the zero coupling of the fundamental mode as a function of the angle, means that a widened reflection pocket about the grating write angle is guaranteed.