Barbara Janoszczyk

Prototype of the side-hole HB optical fiber

A standard polarization maintaining optical fiber (SMPM- single mode polarization maintain) has either an elliptical core or/and an elliptical inner cladding (bow-tie, panda). These kind of fibers usually display low or modest sensitivity to pressure and high sensitivity to temperature. The side-hole optical fibers having two hollow spaces symmetrically placed on both sides of the core are characterized by much higher sensitivity to pressure. This paper presents results of investigations on sensitivity to pressure and on sensitivity to temperature, which can attain the values of 140 rad/MPa*m and 1 rad/K*m, respectively.

Microstructured low and high birefringence four core fibers for sensing applications

Optical fiber strain or bend sensors have been demonstrated for complex monitoring various structures especially in aerospace, marine civil engineering and especially in optical security systems. Optical fiber sensors based on Fabry-Perot interferometers and fiber Bragg gratings are useful for point or slow-multiplied sensor systems. Distributed optical fiber system based on Sagnac interferometers used of low or high-birefringence optical fibers as strain/bend sensing elements. Special optical fibers as four core single mode fibers in Mach-Zehnder interferometer system have been used. In all described cases the high influence of temperature on sensor characteristics is very important disadvantage at measurement systems. In this paper we describe fabrication and characterization of the new four core PCF index guided fiber designed for interferometric bend measurements.

Development of silica glass microstructured optical fibers technology in Poland

Paper presents the state of advance of the silica glass microstructured optical fibers technology n Poland especially in Department of Optical Fibers Technology Maria Curie Sklodowska University. Only in this Department there are the technological apparatus for advanced investigations on the technology of the silica glass optical fibers. In paper was describe the technology of optical fiber photonic structure manufacturing, high silica glass synthesis from vapor phase with MCVD and OVD methods. Next was describe some kinds of microstructured optical fibers witch technologies elaborated in UMCS in support of own and received from cooperated research teams optical fibers structures, modeling and measurements results.

Experimental investigation of the effect of protective coatings on temperature sensitivity of side-hole optical fibers

Side-hole optical fibers are directed towards construction of pressure sensors owing to their extremely high sensitivity to the pressure. However, the fact of negative effect of polymer protective coatings on deformation of optical fiber characteristic has been discovered. In this work the efforts were made to eliminate this undesirable phenomenon by use of standard protective coatings used for production of telecommunication optical fibers. The results of these investigations have appeared negative.

Experimental determination of effect of selected parameters of MCVD process on the properties of formed SiO2 particles

The process of synthesis of SiO2 particles is relatively well recognized theoretically, but not experimentally. In this work we describe the results of experimental examination of an influence of concentration of silicon tetrachloride, temperature of reaction and time of the stay of reagents in the reaction zone on diameters of formed SiO2 particles. The results are presented in the formalism used for characterization of ceramic raw materials.

Experimental structures of silica holey fibers with triangular lattice

Basic structures of silica photonic fibers with triangular lattice made from a single prapreform are presented. Variation of the filling factor was achieved by adjustment of fiber preparation conditions. Fundamental structural and transmission parameters were measured for a chosen fiber. A problem of searching of procedures for further decrease in attenuation of fabricated fibers was formulated on the base of obtained results.

Analysis of sensitivity of side-hole optical fibers to pressure and temperature by the finite element method

In our laboratory there was elaborated the mode of preparation of side-hole optical fibers characterized by high sensitivity to pressure/sensitivity to temperature ratio. This ratio is two magnitude order higher than this obtained for normal SMPM optical fibers. This work presents the quantitative explanation of this advantageous phenomenon. It has presented the mode and the results of calculations of selectivity to pressure in relation to temperature for defined class of side-hole optical fibers. It has resulted that there exist numerous structures of side-hole fibers for which the sensitivity to pressure/sensitivity to temperature ratio is not lower than 1000. Described mode of calculations of selectivity of birefringent optical fibers to pressure in relation to temperature will permit to optimization of these sensor fibers for technological purposes.

Transmission properties and preparation of the side metal pipe optical fibers with silver layers

Technology and basic characterization of new kind of side hole optical fiber with silver layers in the holes named side metal pipe (SMP) optical fiber is presented. The static deposition method of silver layers of several hundred nm thickness from liquid phase was used. Polarization properties of the side metal pipe optical fibers were found.

Technology of substrate of liquid crystal core fibers with nickel electrodes

Liquid crystal circular core optical fibers cannot have a stable structure of arrangement because of misfit of core geometry and properties of liquid crystals. Fibers of high ellipticity of core are much better in this case but controlling the state and degree of arrangement of a liquid crystal by external electric field requires application of high voltage. The work presents the technology of substrate of liquid crystal core fibers in the form of quartz glass capillaries with highly elliptic central hole and two additional holes placed at both sides of the central one along the fiber. On the surface of side holes layers of nickel were deposited by thermal decomposition of nickel carbonyl from a gaseous phase. Substrates 2 m long with dimensions of central hole 4 x 18 μm were obtained and characterized. The produced substrates may allow preparation of a new generation of liquid crystal core fibers. The work also presents the design of laboratory scale apparatus for preparation of a new generation of liquid crystal core fibers. The work also presents the design of laboratory scale apparatus for preparation of nickel carbonyl as well as conditions of its synthesis.

Preparation of liquid crystal optical fibers

We have made 12 preparations of different optical fibers with circular (diameter 5 micrometer) and elliptical (4 X 18 micrometer) cores made of liquid crystals. We have elaborated drawing of capillaries of suitable dimensions from quartz glass and we have constructed a few stations for successive stages of preparation and measurement of these fibers. We have examined influence of hydroxylation of capillarys inner surface and coating it by polyimide or polyvinyl alcohol on quality of prepared liquid crystal fibers. Acquired relationships for one kind of liquid crystal allowed creation of general rules of preparation of liquid crystals optical fibers. These general rules will surely fit other kinds of liquid crystals.