| 摘要 |
A method for erasing some or all of at least some of the grating elements of a grating inscribed in an optical waveguide such as an optical fiber or a cane structure (a more rigid optical waveguide), or, more generally, for selectively altering the index of refraction of a span of an optical waveguide, and products provided by the method. A temperature profile suitable for achieving a predetermined desired apodization (shaping of the grating strength) is determined, and then a focused laser beam, from for example a CO2 laser, is directed to a target site on the optical waveguide selected as a suitable point from which to direct the laser beam and so introduce heat into the optical waveguide. The laser beam is held on the target site only so long as is necessary to create at least a portion of the temperature profile. The laser beam may then be redirected to other target sites on the optical waveguide, or may be swept along the optical waveguide at a rate suitable for creating further portions of the temperature profile. The laser beam may also be applied to an optical waveguide not having a conventional (small-scale) grating so as to create large-scale gratings, such as so-called long-period gratings, and including aperiodic and higher-functionality large-scale gratings.
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