Twisted Silica Microstructured Optical Fiber with Equiangular Spiral Six-Ray Geometry

Abstract

This work presents fabricated silica microstructured optical fiber with special equiangular spiral six-ray geometry, an outer diameter of 125 µm (that corresponds to conventional commercially available telecommunication optical fibers of ratified ITU-T recommendations), and induced chirality with twisting of 200 revolutions per minute (or e.g., under a drawing speed of 3 m per minute, 66 revolutions per 1 m). We discuss the fabrication of twisted microstructured optical fibers. Some results of tests, performed with pilot samples of designed and manufactured stellar chiral silica microstructured optical fiber, including basic transmission parameters, as well as measurements of near-field laser beam profile and spectral and pulse responses, are represented.

Experimental researches and testing of silica twisted six-GeO2-doped core microstructured optical fiber. Part I: fusion splicing with telecommunication optical fibers and differential mode delay map measurements

“…For this purpose, first of all, the motor was installed to the feed unit of tower (in the first stage of modification it was stepper, while further in the final configuration it was replaced by commutator motor), that added the rotation option to the drawing system [82][83][84] with rotation speed up to 2000 revolutions per minute. Because MOF / PCF structure contains air holes (that provide features, much differing from properties of typical telecommunication optical fibers), special matching system was developed, fabricated and installed on the drawing tower to feed excess pressure feeding to the MOF cane for control and management of capillary size under cane rotation during MOF drawing process 85,86 . As a result, we successfully fabricated two series of 20…30 m long pilot samples of chiral silica MOFs 77 with 6 GeO2-doped graded-index (Fig.…”

“…G.652 91 ), jointed to tested optical fiber at the start of measurements centrally and further under precision specified radial offset with respect to core center. Here we utilized based on stroboscopic effect DMD analyzer workstation R2D2 lab kit 83,86,[92][93][94][95] for laser-excited optical pulse response measurement under desired precision offset launching conditions after propagation over tested fiber optic link, containing ~500 m long MMF and researched 2 m long silica 6-core MOF with graded refractive index profile of cores and induced twisting 100 rpm. R2D2 transmitter unit is based on Fabry-Perot laser diode (FP LD), that generates quasi-Gaussian optical pulse at wavelength =1310 nm with width at a half maximum (FWHM) ~340 ps.…”

Silica microstructured optical fiber with centralized inclusion of seven GeO2-doped capillaries and induced twisting. Part I: fabrication of pilot samples

“…Earlier on [29][30][31][32][33] we discussed technological issues of drawing tower modifications to provide fabrication of optical fibers with induced twisting. Here we utilized the same technique, proposed in work 34 , which is based on preform rotation during the drawing.…”

“…Therefore, during MOF drawing, an excess pressure is fed into the MOF cane to manage and control capillary dimensions. So, a passage to fabrication twisted MOFs required the development of special adapter 32,33 , that connects an excess pressure hose to the top end of the cane and fixes it without twisting, provides cane rotation during the MOF drawing under the desired speed with simultaneously excess pressure supplement and eliminates drop of pressure in the space between the hose and the top end of the cane due to sealed internal space of the rotational adapter.…”

Twisted Few-Mode Optical Fiber with Improved Height of Quasi-Step Refractive Index Profile

“…We performed some modifications of the drawing tower to induce twisting on FMF during its drawing. The detailed description of modification is represented in the earlier on published work [30]. Usually, preform is fixed in a mechanical chuck of the feed unit, that input preform to the heat space of high temperature furnace.…”