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AssigneeThe United States of America as represented by the Secretary of the Navy
InventorsCharles G. Askins, Edward J. Friebele
Estimating the term…
A process for making an optical reflection grating in a glass fiber includes exposing an unjacketed optic fiber to a single writing pulse from a pair of interfering light beams that form an interference pattern in the fiber. A novel optical fiber has at least one optical grating with a preselected Bragg spacing in at least one region of the fiber, with a periodic modulation in its index of refraction, with high thermal stability and narrow linewidth. A process for making an array of optical reflection gratings in a glass fiber includes exposing a fiber to a plurality of writing pulse from a pair of interfering light beams that form an interference pattern in the fiber, where these pulses are applied sequentially as the fiber is drawn from a draw furnace. A novel optical fiber has a plurality of unspliced gratings with high thermal stability and narrow linewidth.
A process for writing an optical grating into a glass fiber, comprising the steps of:
A glass fiber including at least one optical grating with a preselected Bragg spacing in at least one region of said fiber, wherein said grating is formed by transversely exposing said glass fiber to a pulse from a pair of interfering writing beams, to create an interference pattern in said fiber, Wherein said pulse has sufficient fluence to induce an index modulation in said fiber corresponding to said interference pattern, wherein said grating has a periodic modulation in its index of refraction, wherein said modulation remains essentially constant after annealing at a temperature of about 300.degree. C.
A glass fiber including at least one optical grating with a preselected Bragg spacing in at least one region of said fiber, wherein said grating has a reflectance bandwidth, and wherein said reflectance bandwidth of said grating is not more than about 20% wider than the theoretical bandwidth of said grating, wherein said theoretical bandwidth is given by the formula .lambda./2L, wherein L is the axial length of said grating and .lambda. is the wavelength of interfering write beams used to write said grating.
An unspliced glass fiber including a plurality of optical gratings with preselected Bragg spacings in preselected regions on said fiber, wherein each of said plurality of gratings is formed by transversely exposing said glass fiber to a pulse from a pair of interfering writing beams, to create an interference pattern in said fiber, wherein said pulse has sufficient fluence to induce an index modulation in said fiber corresponding to said interference pattern, wherein said fiber is at least about 5 meters long.
Dependencies are inferred from the claim text.