Patent ID: 7704682
Filing Date: 2010-04-27
Classification: G02B,G03F

Abstract:
1. A method of manufacturing an optical fiber having a Bragg grating, comprising: applying heat from a heat source to a portion of the optical fiber and thus diffusing impurities existing in a core of the optical fiber into a cladding of the optical fiber, so as to adjust an effective refractive index for a guided mode in the optical fiber corresponding to a predetermined wavelength, wherein the impurities include germanium, boron and phosphorous and the germanium is doped into the core of the optical fiber at high density, exposing UV light from an optical source to a phase mask having a periodic surface relief structure wherein the optical source is an excimer laser having a high output power; and, fabricating the Bragg grating having a predetermined period in the optical fiber using diffraction and interference of the UV light due to the periodic surface relief structure of the phase mask, wherein said applying the heat comprises applying the heat under conditions predetermined to transition a resonant wavelength of the Bragg grating to a desired resonant wavelength, and manufacturing a second optical fiber having a second Bragg grating having a different resonant wavelength than the Bragg grating, when the second optical fiber has the same refractive index as the optical fiber, and when the same phase mask is used, by applying heat to the second optical fiber differently than the heat applied to the optical fiber to diffuse impurities differently in the second optical fiber.