摘要:
A fiber optic sensor is provided. The fiber optic sensor includes a fiber core having a plurality of grating elements wherein, the grating elements comprise a periodic or a quasiperiodic modulated microcrystalline and silicon dioxide tetrahedral structure and a cladding disposed about the fiber core.
摘要:
A fiber optic sensor is provided. The fiber optic sensor includes a fiber core having a plurality of Bragg grating elements wherein, the grating elements comprise a periodic or a quasiperiodic modulated microcrystalline and rigid silicon dioxide tetrahedral structure and a cladding disposed about the fiber core.
摘要:
Methods for coating an optical fiber with optical fiber Bragg grating (FBG) with a hermetic coating, particularly a coating of carbon, are employed to avoid ingress of gases, vapors or fluids in the ambient environment. This ingress can be from water or hydrogen, which can diffuse in the fiber glass and cause deviation/drift in the measured Bragg measurements. Bragg gratings that maintain the grating strength at temperatures in excess of 1000° C. are used and can be formed by heating the fiber above 1000° C. in a chamber with a reactive gas that produces deposition of carbon.
摘要:
In an optical waveguide fabricated to provide spectral filtering by a periodic mode coupling between the core and cladding the spectral profile may be shifted in wavelength if the core or cladding is photosensitive. This is especially useful in the case of long period gratings used as gain flattening filters, as a relatively low dose of radiation, compared with that typically required to fabricate a Reflection Bragg Grating in the same fiber, provides a sufficient shift for filter tuning purposes. Subsequent thermal exposure can stabilize the filter performance over the expected temperature range, while exposure to higher temperature reverses the radiation induced shift.
摘要:
A refractive index grating comprising an optical fiber having at least one radiation-sensitized portion, in a longitudinal section of the optical fiber, containing a periodic variation of refractive index. The refractive index grating has an initial magnitude that changes no more than two percent after conditioning at a temperature of 300null C. for a time of ten minutes.
摘要:
A method and article for applying tension to a filament using a filament tensioning apparatus comprising a tensioning holder including at least one support bar. A first carriage is mounted at a first location on a support bar. The first carriage has a first clamp and a voice coil mounted thereon for movement relative to a support bar. A second carriage mounted at a second location on a support bar provides a separation between the first location and the second location. The second carriage has a second clamp and a load cell mounted thereon for movement relative to a support bar. A guide bar extends from the voice coil for contact with the load cell to adjust the separation of the first location from the second location to apply tension to a filament held between the first clamp and the second clamp.
摘要:
Provided is a cladded single crystal sapphire optical fiber. In one embodiment, the innovation provides a method for forming a cladding in a single crystal sapphire optical fiber by reactor irradiation. The reactor irradiation creates ions external to the fiber that enter the fiber, displace atoms in the fiber, and are implanted in the fiber, thus modifying the index of refraction of the fiber near the surface of the fiber and creating a cladding in the sapphire fiber.
摘要:
A method for manufacturing a treated optical fiber for a temperature sensor is provided. The method includes a) obtaining an optical fiber from pure silica or doped by one or more elements from among fluorine and nitrogen, b) imprinting, using a femtosecond laser, at least one Bragg grating in the optical fiber to obtain an imprinted fibe, the Bragg grating extending longitudinally in a portion of the imprinted fiber and being suitable for reflecting light waves propagating along the imprinted optical fiber, the laser having a power greater than or equal to 450 mW, and c) annealing at least the imprinted fiber portion to obtain the treated optical fiber.
摘要:
A method for manufacturing an optical fiber grating that includes first and second gratings that configure an optical resonator, the method including: forming the first grating by radiating ultraviolet light to an optical fiber so that a irradiation intensity Z satisfies the following Equation 1: Z≦(ΔλS/x+0.04556Y2+1.2225Y)/(0.05625Y2+1.6125Y) . . . Equation 1, where, Z represents an irradiation intensity (mJ/mm2) of the ultraviolet light, ΔλS represents the maximum shift amount of a reflection center wavelength of the first grating that is allowed as long as reflection wavelengths of the first grating and second grating overlap each other, x represents a shift amount of the reflection center wavelength per temperature change of 1° C. (nm/° C.) in the first grating, and Y represents an intensity (W) of the wave-guided light.
摘要:
A method for optimizing the architecture of a linear sensor array using WDM-TDM technology and stabilizing the reflectivity spectral profile of the fiber Bragg gratings of the sensors against the influence of environmental factors such as pressure and temperature is provided. The method includes stripping a portion of the foamed coating on the exterior of an optical fiber in the region of the fiber Bragg grating to thin the coating in the region of the grating. After the coating is stripped and the optical fiber cleaned, the area of stripped fiber is recoated with an unvoided plastic.