Showing papers by "Marian Marciniak published in 2001"

Solving present and future problems in optical telecommunications with PBGs

Abstract: The all-optical network should take advantage of photonic devices of various kind that above all should provide the means for all-optical signal processing. Photonic band-gap structures (PBG, photonic crystals) are expected to be very helpful for achievement of several functions that an all-optical network asks for. To this purpose many proposals have been elaborated and an intense research is still underway. In the lecture the state-of-art and potential future applications of PBG structures in optical telecommunication systems are reviewed. Special attention is paid to fiber Bragg Gratings that are special kind of photonic band-gap structures. In wavelength-division-multiplexed systems the wavelength sensitivity of PBGs and their filtering properties resulting from it are of particular interest. Possible locations of PBG-based devices within the advanced all-optical network architecture are indicated and their functional parameters are discussed.

Development of IP/WDM optical networks

Abstract: Optical wavelength-routed IP/MPLS networks could be a valid solution in the short time. Optical burst switching may represent an interesting method in the mid/long term. Optical packet switching can be seen as the last step of such an evolutionary path. To achieve satisfactory performance, significant efforts are required in developing key optical devices and components such as semiconductor optical amplifiers, optical gates and space switches, wavelength converters, fast tunable lasers and filters, and wavelength routers. Also some breakthroughs are needed in order to realize mature optical devices which allow dynamic buffering of optical packets.

QoS guarantees in IP optical networks using MPLS/MPLambdaS

Abstract: We present some issues related to QoS guarantee in next generation terabit IP optical networks. We report the basics of MPLS/MPLambdaS technologies and some of their functionalities that enable a QoS protection environment for IP networks. An application example of MPLS/MPLambdaS in photonic packet switching and wavelength switching to provide QoS is also presented.

Optical transparency in next generation IP over all-optical networks

Abstract: The evolutionary and/or revolutionary strategies of optical telecommunication future development towards next generation IP over optical networks as well as their social impact are discussed. The desirable extent of network transparency in an advanced all-optical network architecture is studied in detail. Conditions for the successful deployment of transparent and all-optical terabit networks are discussed, and intermediate issues are pointed out.

On retrieval of permittivity profile

Abstract: A new theoretical approach is proposed for solving the inverse problem of dielectric permittivity retrieval by a reflected field. It is based on the approximate solution of an integral equation, obtained by combining the integral equation for the electromagnetic field inside the object with an integral expression, which determines the diffracted field in the external region after the field inside it. The solution method based on the Tichonoffs (1983) theory of ill-posed problems is proposed. Also a simple scheme for fast estimation of the object permittivity profile has been worked out.

New method of SBS counteracting in long distance analog CATV link

Abstract: Analysis of stimulated Brillouin scattering (SBS) in externally modulated lightwave long distance AM-CATV systems is presented. The stimulated Brillouin scattering threshold power (P/sub SBS//spl ap/7 dBm) is the main limiting factor of transmission distance. Two methods of increasing the SBS threshold are compared: well known dithering method and new one, called initial pulse modulation method.

Optical gain enhancement in PBG structure with active n-i-p-i superlattice

Abstract: In a certain spectral range the extinction coefficient K in n-i-p-i layers becomes negative at the high excitation levels It results in the appearance of the light amplification The extinction coefficient in n-i-p-i layers depends on the wavelength and the difference in the quasi-Fermi levels /spl Delta/F We considered the model, when a pump, which can be electrical as well as optical, excites uniformly all active layers and calculated light transmission characteristics versus /spl Delta/F which is the same within all active layers In the present work we consider the optical mechanism of the pump, and solve the nonlinear problem of the pump light propagation through the photonic band gap (PBG) structure and the linear problem of a probe light transmission through the same structure with excited active layers

Methods for description of the total field propagation in the irregular dielectric waveguides

Abstract: Numerical and semi-analytical methods useful for analysis of the total field propagation in dielectric waveguides with sharp and smooth discontinuities are reviewed. The efficiency of these methods to model the field propagation in such structures is discussed comparatively. As an example, spatial transient regime of the radiation field propagation in planar step-index waveguide excited by a Gaussian beam is simulated numerically by two different beam propagation methods.

IP over optical network: strategy of deployment

Abstract: In this paper, we present main issues of application IP technology directly over optical transport network. The capabilities of WDM transmission systems and techniques which allow the integration of IP with the physical layer are discussed. A detailed description of most solutions is reported. In particular the MPLS/MPλS techniques are discussed in detail. Also problems for further development are outlined.

IP/optical networks: the impact of optical transparency

Abstract: The state-of-the art of transparent optical telecommunication technology is reviewed and possible directions of the future developments are outlined. The fundamentals and results of numerical investigation of the influence of the nonlinear optical phenomena on transmission quality and nonlinear products accumulation in multispan dense wavelength division multiplexed (D-WDM) optical fiber telecommunication systems are reported. Four-wave mixing (FWM), self-phase modulation (SPM), cross-phase modulation (XPM), and stimulated Raman scattering (SRS) phenomena are taken into account. Various types of optical fibers as well as different channel number and channel spacing are taken into account in the analysis.

Impact of apodisation on fiber Bragg grating reflection and phase responses

Abstract: The paper presents the impact of the apodisation of the profile of refractive index changes on fiber Bragg grating reflection and phase characteristics. The evaluation was performed on the basis of a describing function, with the use of the coupled modes theory for aperiodic structures. The nonuniform profile of the modulated refractive index was applied as a means of side bands reduction.

Modelling and optimization of planar waveguide with layered cladding

Abstract: Planar waveguides with photonic bandgap guiding properties are studied. It is shown that a slight deviation from the periodicity in the photonic bandgap multilayers can provide non-dispersive transmission of wide-band signals of high power, as well as reduce the number of sub-layers of the multilayer coating in comparison with a periodical one to provide wave guiding.