Patent ID: 7486858

Claim:
A method for writing a device into an optical fiber, comprising: (a) providing a segment of optical fiber; (b) providing a heating unit including a resistive heating element having a thickness that is smaller than a selected period for the optical device, the resistive heating element having a hole through its thickness, the hole being dimensioned to closely receive the fiber segment, the resistive heating element creating a localized, rotationally symmetric heating zone at the hole, the heating zone being shorter than the selected device period; (c) mounting the fiber segment into the heating unit with the fiber segment threaded through the hole in the resistive heating element; (d) positioning the fiber segment with respect to the resistive heating element such that a selected portion of the fiber segment is located within the heating zone; (e) raising the temperature of the resistive heating element to cause a change in the refractive index profile of the selected portion of the fiber segment.