Evgeny M. Dianov

Influence of hydrogen loading and UV irradiation on optical properties of phosphorus-doped fibers

Optical loss in a hydrogen-loaded phosphorus-doped fiber treated with a 193 nnm ArF eximer laser light was studied. It follows from the experiments that additional noptical losses in the region of 1.0-1.6 µn must remain negligible after writing a Bragg ngrating. Absorption spectra of the phosphorus-doped fiber after hydrogen loading and nUV-irradiation differ strongly from that of a germanium-doped fiber.

Influence of drawing conditions on radiation-induced attenuation of pure-silica-core fibers in the near-IR range

Three single-mode fibers have been drawn from each of four MCVD-made pure-silica-core F-doped-silica-cladding preforms, the drawing parameters (temperature, speed, and tension) being varied among the fibers in a controlled fashion. The initial optical loss spectra in the range 200-1700 nm as well as radiation-induced attenuation (RIA) spectra in the near-IR range under γ-irradiation to 82 kGy (7.6 Gy/s) are measured in the fibers. RIA is found to increase significantly with increasing the drawing temperature and to increase much less with increasing the speed and tension. The mechanism of the strong drawing temperature effect on RIA is argued to be associated with a rise in the fiber silica fictive temperature, which, in turn, enhances the concentration of strain-assisted radiation-induced self-trapped holes.

Hollow Core Fibers with Single and Double Nested Capillaries Cladding and Fiber Based Raman Lasers

The revolver hollow core fibers of three different types were fabricated, including fibers with double nested capillaries in the cladding. Efficient hydrogen Raman lasers (1064 ⇒1907 nm) based on all of these fibers were demonstrated.

Fabrication of Aluminum and Phosphorus Doped Optical Fibers by Sintering a Powder Mixture

We present the method of fabrication of Al- and P-codoped silica optical fiber preforms by sintering SiO2 and AlPO4

Novel fiber optic acoustic sensor based on asymmetrically sensitive Sagnac interferometer

A novel configuration of a single-loop Sagnac interferometric acoustic sensor based on asymmetric desensitization of a half of the coil (loop) to phase modulation is presented. Sensitivity as high as 10-5 Pa at a maximum frequency response of ~8 kHz is demonstrated in underwater experiments.