Method of making gratings and phase masks for fiber grating fabrication
AssigneeOFS Fitel, LLC
InventorsBenjamin J. Eggleton, Misha Sumetsky, Paul S. Westbrook
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Abstract
In accordance with the invention, the fabrication of a grating phase mask is improved by providing a multiple-scan exposure which can provide an accumulated exposure that is effectively phase modulated or modulated rapidly in amplitude. Applicants have determined that exposure scans can be chosen so that each is modulated in amplitude and without modulation in phase, but the accumulated exposure of the multiple scans is modulated in phase and/or modulated in amplitude. The improved method can be used to make phase masks for fabrication of sophisticated fiber gratings such as superstructure gratings.
Claims12
A method for fabricating a phase mask comprising the steps of:
- supplying a substrate;
- coating the substrate with resist;
- exposing the resist to a plurality of spatial holographic illumination steps according to the expanded terms of an equation describing an optical grating;
- developing the resist;
- and
- etching the substrate.
A method of writing a grating in an optical medium comprising the steps of:
- providing an optical medium comprising a photosensitive region;
- and
- exposing the photosensitive region to a plurality of holographic illumination steps according to the expanded terms of an equation describing an optical grating.
Dependencies are inferred from the claim text.