This PDF file contains the front matter associated with SPIE Proceedings Volume 7120, including the Title Page, Copyright information, Table of Contents, Introduction (if any), and the Conference Committee listing.

The paper analyzes a modal structure of the guided modes in photonic liquid crystal fibers (PLCFs) by using numerical methods and presents experimental verification of the theoretical results. The theoretical analyses is based on numerical methods applied to find solution of the Helmholtz equation that describes possible forms of modal field propagating inside photonic crystal fiber (PCF) of defined geometry, as well as optical parameters. Numerical calculations based on the Finite Difference method were preformed for two different kinds of digitization of the PLCF structure (i.e. for using square and triangular lattice). Several boundary conditions applied in the case of analyzed lattices such as: constant, Dirichlet and semi-transparent condition were discussed. Input parameters of preformed simulations can be divided into two groups: physical and purely numerical. Physical parameters are: wavelength, number of capillaries, and spatial distribution of refractive index (in cross section of fiber surface). Numerical parameters are: type of used lattice, resolution of the lattice and the boundary condition. Numerical output is the value of effective refractive index and additionally shape of propagating mode field. In experimental part the measurements of numerical aperture (NA) were done in the way to find effective refractive indices of modes propagating in PCFs and PLCFs.

In this paper the analyses of the linear and nonlinear light propagation in the photonic crystal fiber infiltrated with nematic liquid crystal is presented. Our theoretical investigations, carried out by using the finite difference beam propagation method, show the extreme importance of the discrete space representation aspect. The main aim of this work is to reveal that application of the triangular grid for the discretization of the analyzed structure of the photonic crystal fiber with the hexagonal symmetry gives more reasonable results than in the case of the standard square mesh utilization.

Guiding properties of liquid crystal (LC) filled photonic crystal fibers (PCFs) can be easily tuned by using an external electric field. In this paper we discuss electric field distribution within the LC filled PCFs for three different electrodes configurations: two flat parallel electrodes, four electrodes arranged in the V-groove assembly, and finally two short parallel electrodes together with two conductive rods placed on both sides of the fiber. The last two configurations enable four different directions of the electric field depending on the applied voltage

Due to low attenuation in third transmission windows, single mode fibers are the most popular medium, also, in supporting transfer of optical power to various devices. For this reason ability to achieve the maximum of optical power is still actual. There are two different ways to estimate the optical power in the fiber core. The first is analysis of mathematical model in the aim of getting the best wavelength guaranteeing maximum of optical power. Second way is approximation of distribution of optical power along radius without changes of wavelength and with constant attenuation coefficient. In this paper the second way of evaluation was chosen, where distribution of optical power in single-mode fiber is approximated by Hermite or Legendre polynomials.

The paper presents theoretical analysis of propagation LP-modes in structure of double layer capillary waveguide. The solution of wave equation is used to analysis of weakly guiding properties of capillary waveguides. The paper presents the theoretical basics and obtained results of calculations. It is show the optical characteristics of analyzed structure. The influence of different parameters on LP-mode transmission is also investigated.

We report on experimental studies of phase and group modal birefringence vs. temperature in two highly birefringent (HB) photonic crystal fibers, in which birefringence is caused by filling factor asymmetry. The sensitivity measurements were carried out at two wavelengths 633 and 834 nm. Our results show that temperature sensitivity in the HB photonic crystal fibers is two orders smaller then in traditional HB fibers. Simultaneously, our results exhibit weak dependence of group modal birefringence on temperature.

In this work we present experimental results of the influence of hydrostatic pressure on polarization and propagation properties of the photonic crystal fibers infiltrated with liquid crystals. Two ranges of Photonic Band Gaps (PBGs) were observed and hydrostatic pressure was found to narrow the PBGs and also to introduce changes in the state of polarization The results obtained suggest great potential of the LC-infiltrated photonic crystal fibers for prospective constructions of fiber optics pressure sensors.

Supercontinuum radiation in photonic crystal fibers (PCFs) has recently found exciting applications in metrology, fundamental research, and medical sciences. Intensive efforts have been put into optimizing supercontinuum radiation parameters such as spectral width, flatness, and brightness. This work presents results of supercontinuum generation in suspended core microstructured optical fibers. These results are compared with supercontinuum generation in photonic crystal fibers with hexagonal lattice.

We present the results of measurements of modal birefringence and temperature sensitivity of birefringent holey fibers fabricated by Fiber Optic Group, University of Marie Curie-Sklodowska (UMCS) in Lublin, Poland. The birefringence measurements were carried out in a wide spectral range of 0.63 - 1.57 μm in two fibers with different hole diameters and pitch distances. Our results show that absolute value of birefringence increases against wavelength and is one order of magnitude greater than in conventional highly birefringent fibers. The measurements of temperature sensitivity carried out for bare fibers show that zero sensitivity can be achieved at certain wavelength.

We present an application of the interferometric method for measuring the chromatic dispersion of microstructured birefringent fibers in a wide wavelength range employing a portable spectrometer with resolution of 0.5 nm. The method utilizes an unbalanced Mach-Zehnder interferometer with a tested fiber in one arm and the other arm with a controllable path length. We recorded a series of spectral signals to find the length of the reference arm (with compensated group delay coming from the tested fiber) as a function of wavelength. We also present the results of dispersion measurements in three highly birefringent microstructured fibers manufactured by the Laboratory of Optical Fiber Technology, Maria Curie-Sklodowska University, Lublin, Poland.

RIB waveguides were fabricated with the use of selective, wet chemical etching of two-component waveguide films SiO₂:TiO₂ which were obtained using sol-gel method. Photoresist was applied as a mask in the process. The etching of the layers SiO₂:TiO₂ was carried out in water solutions of ammonia fluoride. The paper presents results of theoretical analysis, technological characteristics, and power distributions in the obtained strip waveguides.

The studies of undoped and p porous silicon -doped type micro and macro porous silicon (PS) prepared by chemical and electro-chemical etching are reported here. The optical reflectance and photoluminescence of samples obtained under different conditions have been investigated. The PS investigated samples exhibited photoluminescence (PL) and antireflection properties (ARS).

The paper presents a new glass ceramics of the SiO₂-B₂O₃-Na₂O-LaF₃ system in which nanocrystallization of LaF₃ could be obtained. Thermal stability of glass and the crystalline phases formed upon heat treatment were determined by DTA/DSC and XRD methods, respectively. The effect of incoming of Pr³⁺ to LaF₃ crystals in the glassy host has been shown in the emission spectra. The ³P₀ → ³H_J emissions have been much stronger in glass-ceramics what supports the suggestion that ³P₀ → ¹D₂ non-radiative decay dominates the relaxation of ³P₀ for Pr³⁺ ions in the as-made glass.

The paper presents the problem of repeatability of ion exchange processes with respect to planar waveguide structures produced with the application of this method. A numerical control method of diffusion processes based on the assumed mathematical model of exchange processes has been presented. The results of diffusion process control have been illustrated by the measurement results of the produced waveguides. The provided research results, involving the repeatability of the said technological processes, refer to sodium-silica glass with the admixture of silver ions Ag+.

The investigation of crystallization kinetics of oxyfluoride glass 37SiO₂ - 10Al₂O3 - 43PbF₂ - 4,5ZnF₂ - 0,2LaF₃ - 5,3ZnO - 0,5Nd₂O₃ using differential scanning calorimeter were presented. Thermal analysis were performed by using Friedman and Ozawa - Flynn - Wall methods. Reaction rate and activation energy of the crystallization process as function of reaction progress were calculated on the base of DSC measurements performed with heating rates 5, 10, 15^oC/min. Glass ceramic oxyfluoride matrix were formed by thermal treatment of as melted glasses. Obtained glass-ceramic structure showed higher level of emission and less FWHM of luminescence band compared to as melted glass.

The manufacturing and properties of multicore optical fibers were presented. The aluminosilicate glasses doped with neodymium 1,5 (wt %) posses good optical and thermal properties were melted. Fabricated glasses were used as cores in manufactured multicore fiber. Rod in tube drawing technique was used to fabricate active 23-core double clad optical fiber. Luminescence spectra and luminance distribution of the obtained fibre were presented. It could be possible to apply manufactured fiber to build high power fiber laser with phase - locking using Talbot effect.

Technology of tellurite glasses from the TeO₂-WO₃-PbO-La₂O₃ has been investigated. The effect of lanthanum oxide content on tendency to the crystallization of glassy matrix has been studied. Differential thermal analysis DTA/DSC, XRD measurement have been considered in term of lanthanum oxide influence. The refractive indices (n) for series of glass compositions with various La₂O₃ contents compared with glass without La₂O₃ addition has been measured. From obtain results it has been stated that the refractive index slightly increases with the addition of the lanthanum oxides in all glass of compositions. Double crucible drawing technique was applied to drown tellurite optical fibre with high numerical aperture (0.8).

Parameters of a waveguide may be investigated with great resolution by using the m-line spectroscopy method. By depositing successive layers on the waveguide the propagation conditions of the structure may be changed. In this paper investigations of multilayer waveguide structures by the generalized m-line spectroscopy method have been presented. Multilayer waveguide structure is constructed by depositing successive layers on gradient index waveguide performed in glass by the ion-exchange method. The depositing layers are optimally selected in order to estimate their refractive indices, thicknesses and other parameters.

Recently we have fabricated at Institute of Electronic Materials Technology (ITME) a microstrucuted fiber made of silicate glass NC21A synthesized in-house at ITME. Fabricated fiber is build of three rings of holes around slightly elliptical core (2.6 μm x 3.4 μm). Dispersion properties of the fiber are calculated based on real structure with biorthonormal basis method. Fabricated fiber has a birefringence at the level of 10-3 at 1.5 μm. A zero dispersion is achieved for the wavelengths 860 nm and 870 nm, respectively. In this fiber, pumped with 100 fs pulses with energy of nJ level, ultra broadband supercontinuum generation in the range 400 - 1600 nm has been achieved.

In this paper we report on fabrication of all-Solid photonic Cladding and Air Core fiber (SCAC fiber). As far as we know it is a first reported fabrication of such PCF. Microrods are made of commercially available lead-oxide F2 glass (SCHOTT Inc.) with a refractive index n_D=1.619, while as background we use a borosilicate NC21 glass synthesized in-house at ITME with a refractive index n_D=1.533. A fabricated fiber has a lattice constant of Λ≈7.49μm and microrods diameter of d≈4.0μm. Air core has a diameter of D_R=3.67μm and total fiber diameter is D_fiber=123.80μm.

In this paper we report on use stack and draw technique to develop volume 2D photonic crystals made of two types of soft glasses with a large difference of refractive index. Existence of partial photonic bandgap in the material is predicted and modeled.

In the paper we present a new method of analysis of the optical fiber Lyot depolarizer based on application of an additional depolarization matrix in the MuellerStokes equation. As a result we found that the degree of depolarization of the light coming out of the Lyot depolarizer depends not only on length and birefringence of the highly birefringent (HB) fibers used as the Lyot depolarizer but also on coherence and polarization of the light coupled into the depolarizer.

This paper presents information about detection of radiation by using side light optical fibers. The idea of the angular dislocation sensor is based on utilization of cylindrical optical fibers with performed prismatic disturbance. Shaped side optical fibers are used mainly in lighting, but they can be also applied in angular detection of radiation.

The paper presents construction and research results for micro-bend fiber loop measuring heads of the multipoint pressure sensor. The manufactured versions include a head with changes in bend radius as well as a two-state head, along with a sensor network realized by using the two-state heads.

In this work the conception of the fiber Bragg grating (FBG) application in the capacity of the temperature distribution sensor, on the grating length, is presented. In the method of temperature distribution measurement, by using of FBG element, the key issue is an estimation of the grating periods distribution (and connected with this estimation - temperature distribution) from measured grating transmission spectrum (an inverse problem). The article presents measurements results used for evaluation of selected methods for solving an inverse problem, which can be used in temperature distribution recovery from FBG spectrum. We have also presented utility evaluation results of the selected methods for numerical solution of the inverse problem for temperature distribution recovery.

The technology of fabrication of the fiber Bragg gratings with different side slopes was investigated. It was proved that confining the fiber length to about 0.3 mm causes the side slope to spread to near 2.5 nm. Such fiber Bragg gratings are very useful in sensor applications.

This paper is a continuation of our earlier works on remote measurement tools for supporting the research on novel photonic materials. The scope of this particular work encompasses especially a brief review of present exemplary implementations of remote access methods to measurement equipment, followed by proposing a design for a system management web-based application and related databases, selection of optimal software technologies and their implementation. Case-study for a real-time working system has been developed and proposed, which utilizes apparatus available at three collaborating laboratories located at Warsaw University of Technology and dedicated to photonics research.

Application of directional-mixed reflectors results in a luminance decrease of the apparent image of light emitting diodes (LEDs), which is advantageous as far as glare reduction is concerned. On the other hand, reflectors have a negative impact on luminous intensity curves of the luminaries. This work analyzes an impact of surfaces with directional-mixed reflection properties in a mirror reflector designed for a luminary equipped with high-power LEDs. We present an algorithm used to determine the shape of the reflector of the surface with small scattering, where the axis twist angle for a parabolic reflector varies in a predefined range and follows a power function.

The original numerical and experimental results of multifrequency optical source, based on erbium doped fiber ring configuration are presented. Eleven spectral lines with very stable 1.5 GHz frequency separation were obtained. To achieve uniform amplitudes of optical frequencies, we propose an implementation of a polarization dependent diffraction efficiency equalizer of the acousto-optic shifter.

The paper presents the results of the optical fiber laser operation based on the double-clad (DC) optical fiber. The laser was pumped through the asymmetrical coupler, designed and manufactured in our laboratory. The optimization method of the coupler parameters is described.

The paper presents different pumping ways of double-clad lasers and a new method using polished, asymmetrical couplers. Asymmetric polished side couplers attain high efficiency of pumping power transmission to the inner cladding of the double-clad fibre. Such a type of pumping allows the laser operating in multiwavelength signal to be designed.

Diffusion processes in thermally diffused expanded-core (TEC) of single mode telecommunication fibers areas, at temperatures t=1900°C ÷2000°C were presented in the paper. The loss of TEC areas of thermally connected telecommunication fibers of different types (G.652 and G.655) in above mentioned temperatures of splicing was theoretically analyzed and counted. In the analysis the loss resulted from the mismatch of mode fields of connected fibers and at the same time the mismatch of the dimensions of transit areas were taken under consideration. Presented analysis allows, assuming the knowledge of the values of core dopant diffusion coefficients, the temperature and the time of splicing, to predict the loss of splicing of different types telecommunication fibers. Consistence of the theoretical calculations with experimental data of thermal connected telecommunication fibers with significantly different parameters, was proved.

We investigate linear and nonlinear light propagation in the multicore fiber. Such a structure, with a periodic modulation of refractive index in one-dimension, allows for the study of discrete optical phenomena. Light intensity distribution in such structure changes with propagation length and also depends on the input beam position. Additionaly, in nonlinear regime it changes with the increase of light power. We present both theoretical and experimental results on the nonlinear light propagation in the silica multicore fiber, where the near infrared wavelength from femtosecund laser Ti:Saphire propagates in a distance of a few centimeters.

Paper presents three optically supplied protection systems developed for use for a fiber segment in a Passive Optical Network and gives assessment and comparison of their characteristics with respect to application of an optical supply.