Abstract:
Packages for long period fiber gratings and other optical components (and methods for forming the packages) are described. According to an aspect of the invention, a hollow tube (14) surrounding an optical fiber (12) containing a long-period grating (21) is collapsed in two areas (22), forming a seal at each end of the tube. According to another aspect of the invention, a hollow tube with a shelf section at each end surrounds an optical fiber containing a long-period grating. The hollow tube is sealed at each end with a fused frit. According to another aspect of the invention, a hollow tube surrounding an optical fiber containing grating is sealed at each end with a glass plug.
Abstract:
Disclosed is a tuning method for optical interference devices which comprise at least one plurality of waveguides (36, 38) arranged to produce a preselected phase shift in light transmitted therethrough.
Abstract:
A method for enhancing the photosensitivity of glasses useful in forming waveguides, where the waveguide material exhibits persistent UV photosensitivity after diffusion of hydrogen or deuterium out of the waveguide material. An optical waveguide fiber (22), with a cladding layer (26) and a portion of the polymeric coating (28) removed, has a core (24) which has been loaded with hydrogen or deuterium to form a waveguide core (24) with an associated baseline refractive index. At least a portion of the exposed fiber waveguide is exposed to UV radiation (32) to induce a change in the refractive index and then annealed to diffuse the hydrogen or deuterium gas out and stabilize the refractive index change. The resulting waveguide fiber retains sufficient UV sensitivity to allow further changes in the refractive index, such as grating formation. This process is useful in fabricating grating devices, modifying or tuning gratings for optimum strength or wavelength charachteristics and providing accurate spatial control of waveguide sensitivity.