Refractive index profile dependent

The simplest case of fibre structure is the step-index one, characterized by a constant circular refractive index profile in the core and polymer cladding of lower refractive index (Figure 3). The refractive indexes of the core and cladding depend on the materials used. The cores of these structures can be prepared from melts as well as from preforms without radial and azimutal variations of the refractive index. To obtain suitable mechanical... 

The effort to solve Eqs.(l) evidently depends on the refractive index profile. For isotropic media in a one-dimensional refractive index profile the modes are either transversal-electric (TE) or transversal-magnetic (TM), thus the problem to be solved is a scalar one. If additionally the profile consists of individual layers with constant refractive index, Eq.(l) simplifies to the Flelmholtz-equation, and the solution functions are well known. Thus, by taking into account the relevant boundary conditions at interfaces, semi-analytical approaches like the Transfer-Matrix-Method (TMM) can be used. For two-dimensional refractive index profiles, different approaches can be... 

If the resulting refractive index profile due to the electrode waveguide is eoded in a DLL, this gives a very efficient z-dependent refractive index update in a BPM-run. Such an approach gains attractiveness, e.g. when quite different cross sections are necessary or intended for the modelling in the thermal and the optical domain. 

The measured reflectivity, R(Q), depends upon the neutron refractive index profile perpendicular to the interface, defined as the z-direction. The neutron refractive index is a function of the scattering length density, Nb, which is the product of the number density N, in units of nuclei per cm3, and the neutron scattering lengths, b, of the nuclei present. Since the neutron scattering length varies from nucleus to nucleus, chances in the nature and composition of the surface result in changes in reflectivity. 

The first term Srh depends on the method of excitation of surface plasmons and the modulation approach used in the SPR sensor and is hereafter referred as to the instrumental contribution. Sri2 describes the sensitivity of the effective index of a surface plasmon to refractive index and is independent of the modulation method and the method of excitation of surface plasmons. The sensitivity of surface plasmon to refractive index Sri2 depends on the profile of fhe refracfive index tih and has been analyzed in Chap. 1 of this volume [ 1 ] for the two main types of refractive index changes - surface refractive index change and bulk refractive index change. 

As mentioned earlier, by selecting the duration of a specific state of polarization and electric field intensity, a specified form of the refractive index profile of the waveguide can be deliberately produced. Eigure 7 presents the refractive index profiles of two waveguides of type "A" produced in the electrodiffusion processes in which the duration of polarization was T = t- = 30 and the values of the electric field intensity were E = 4-18.2 V/mm and E = -9.1 V/mm respectively. The dependencies n(x) are of almost linear nature. The temperatures of both processes were T = 299°C and 272°C respectively. The resulting refractive index profiles vary in depth, which is a result of electric mobility of ions depending on the temperature. In the case of a waveguide produced at a lower temperature, the effect of the diffusion component on the final form of the shape of the refractive index profile in comparison with the electric drift is much smaller. 

The dependence of changes of the refractive index profile of the waveguide on the electric charge flowing in the electrodiffusion process... 

Figure 16 illustrates the distributions of stresses occurring in the BK-7 glass after the diffusion processes of potassium ions K, and silver ions AgA depending on their normalized concentrations u. This presentation allows to compare these functions, defined on the basis of different refractive index profiles. 

Based on the determined effective refractive indices, the refractive index profiles of the waveguides were reconstructed and their modal birefringence as well as the refractive birefringence at the surface of the glass was estimated. The nature of the changes of these values depending on the duration of the heating process is shown in Fig.l8a. 

As can be inferred from the refractive index profiles, the porosity profiles in films may be quite complex, depending on the coating sol structure and its condensation as well the substrate surface properties and its pretreatment. If highly condensed sols are used the profiles of porosity increase from the minimum values at the substrate surface to level out with a rise in distance from the substrate surface. 

The bandwidth of an optical fiber strongly depends on the modal dispersion. The modal dispersion can be controlled by controlling the refractive index profile (RIP), which has a decisive effect on the bandwidth (see Chapter 3) and is a basic and important parameter of optical fibers. The pulse-broadening caused by modal dispersion seriously limits the transmission data rate of multimode fibers (MMFs) because overlapping of the broadened pulses induces intersymbol interference and disturbs correct signal detections, increasing the bit error rate [1]. 

The interfacial-gel polymerization technique is particularly common in acrylic GI POP studies and enables the precise control of the refractive index profile, leading to a maximal bandwidth. However, this batch process requires many complicated procedures. Furthermore, the fiber length obtained at any one time is completely dependent on the preform size. This is a serious limitation in terms of fabrication costs. 

Figure A.9 Refractive index profiles. Broken line is the refractive index profile calculated from Equation A21 using the measured dependence of the mutual diffusion coefficient for a PMMA-DPS system. Solid line is...

On a planar waveguide, the refractive-index profile n(x) depends only on x, so that each positon (x, z) on the ray path is determined by the two component equations of Eq. (1-18) in the x- and z-directions... 

The main purpose of this chapter is to show that pulse spreading depends on the refractive-index profile, and to demonstrate how it can be minimized by a suitable choice of profile. We first examine planar waveguides, for which it is possible to achieve zero pulse spread, and then circular and nondrcular fibers. 

The contribution to pulse spreading due to waveguide dispersion in isolation from material dispersion is found from Eq. (11-37) by assuming n is independent of A. The form of 3t depends on the refractive-index profile. Later, in Section 11-20, we express waveguide dispersion in terms of more convenient modal parameters. 

The modal fields of an optical waveguide depend on all of the physical quantities which define the waveguide, i.e. the parameters which describe the refractive-index profile and the cross-sectional geometry, together with the frequency or wavelength of the source of excitation. From these parameters. 

We next consider a waveguide with a nonuniform refractive-index profile n = n(x, y). The propagation constant now depends on the orientation of the electric field, and the modes are no longer TEM waves. In general the modal fields are not solutions of the scalar wave equation but obey the vector wave... 

The slowly varying fiber in Fig. 19-1 (a) has the z-dependent refractive-index profile n x,y,z). To construct its local mode fields, we approximate the fiber by the series of cylindrical sections in Fig. 19-1 (b) [1]. The profile is independent... 

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