Abstract: Methods for synthesizing fibers having nanoparticles therein are provided, as well as preforms and fibers incorporating nanoparticles. The nanoparticles may include one or more rare earth ions selected based on fluorescence at eye-safer wavelengths, surrounded by a low-phonon energy host. Nanoparticles that are not doped with rare earth ions may also be included as a co-dopant to help increase solubility of nanoparticles doped with rare earth ions in the silica matrix. The nanoparticles may be incorporated into a preform, which is then drawn to form fiber. The fibers may beneficially be incorporated into lasers and amplifiers that operate at eye safer wavelengths. Lasers and amplifiers incorporating the fibers may also beneficially exhibit reduced Stimulated Brillouin Scattering.

Abstract: Methods for synthesizing fibers having nanoparticles therein are provided, as well as preforms and fibers incorporating nanoparticles. The nanoparticles may include one or more rare earth ions selected based on fluorescence at eye-safer wavelengths, surrounded by a low-phonon energy host. Nanoparticles that are not doped with rare earth ions may also be included as a co-dopant to help increase solubility of nanoparticles doped with rare earth ions in the silica matrix. The nanoparticles may be incorporated into a preform, which is then drawn to form fiber. The fibers may beneficially be incorporated into lasers and amplifiers that operate at eye safer wavelengths. Lasers and amplifiers incorporating the fibers may also beneficially exhibit reduced Stimulated Brillouin Scattering.

Abstract: Methods for synthesizing fibers having nanoparticles therein are provided, as well as preforms and fibers incorporating nanoparticles. The nanoparticles may include one or more rare earth ions selected based on fluorescence at eye-safer wavelengths, surrounded by a low-phonon energy host. Nanoparticles that are not doped with rare earth ions may also be included as a co-dopant to help increase solubility of nanoparticles doped with rare earth ions in the silica matrix. The nanoparticles may be incorporated into a preform, which is then drawn to form fiber. The fibers may beneficially be incorporated into lasers and amplifiers that operate at eye safer wavelengths. Lasers and amplifiers incorporating the fibers may also beneficially exhibit reduced Stimulated Brillouin Scattering.

Abstract: An in-line fiber etalon strain sensor, and method for making the sensor, is disclosed. The in-line fiber etalon strain sensor uses a short segment of silica hollow-core fiber spliced between two cleaved sections of single-mode fiber to form a mechanically robust in-line cavity. In making the sensor, a portion of a protective coating is removed from one end of each of the two cleaved sections of the single-mode fiber to form a bare portion adjacent to a partially reflective end face on each fiber section. The silica hollow core fiber is fabricated to have the same outside diameter as each of the bare portions of the fiber sections.

Abstract: A strain sensor system formed from a laser cavity where changes in length of the cavity are used to measure strain. The cavity can include a passive optical fiber strain sensing section and/or an active doped optical fiber section that lases when pumped by a laser pump. The cavity can be a ring or linear cavity with or without mode locking. The light oscillating in the cavity sets up multiple oscillation modes. The multiple modes create beat modes or frequencies. The measured frequency difference between beat mode frequencies is inversely proportional to the length of the cavity. The measured frequency change in one of the mode frequencies or one of the beat frequencies is proportional to the absolute strain on the fiber. A heavy metal fluoride glass sensing section makes the sensor temperature insensitive.

Abstract: A fast process for photowriting a permanent, high efficiency optical grating comprises darkening glass by irradiation and photobleaching the darkened glass by exposing the glass to interfering writing laser beams, thereby forming the grating.

Abstract: 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.

Abstract: Optical fibers and glass composition comprising a mixture of barium oxide, gallium oxide, germanium oxide, and a modifying agent selected from lanthium oxide, indium oxide, and mixtures thereof; molar ratio of barium oxide to gallium oxide is from about 4:1 to about 1:1, preferably 2:1 to 1, and especially about 1:1; amount of germanium oxide is at least 40 mole percent, preferably 60 to 95 mole percent, and especially 65 to 90 mole percent; about 0.1 to about 5 mole percent, preferably 0.5 to 4, of gallium oxide is replaced with the modifying agent. The optical fibers made from the glass composition defined herein, with or without the modifying agent, have light transmission wavelength band of about 0.3 to 4 microns; lower optical loss than silica-based optical fibers, the minimum optical loss of the novel fibers having the potential of 0.05 dB/km at 2 microns.