Although Fiber Bragg gratings (FBGs) are well known devices, their using as all-optical switching elements has been
still examined. Current research is focused on optimization of their properties for their using in future all-optical
networks. The main problem are high switching intensities needed for achieving the changes of the transmission state.
Over several years switching intensities have been reduced from hundreds of GW/cm2 to tens of MW/cm2 by selecting
appropriate gratings and signal parameters or using suitable materials. Two principal nonlinear effects with similar
power requirements can result in the bistable transmission/reflection of an input optical pulse. In the self-phase
modulation (SPM) regime switching is achieved by the intense probe pulse itself. Using cross-phase modulation (XPM)
a strong pump alters the FBG refractive index experienced by a weak probe pulse. As a result of this the detuning of the
probe pulse from the center of the photonic band gap occurs. Using of XPM the effect of modulation instability is
reduced. Modulation instability which is the main SPM degradation mechanism. We focused on nonlinear FBGs based
on chalcogenide glasses which are very often used in various applications. Thanks to high nonlinear parameters
chalcogenide glasses are suitable candidates for reducing switching intensities of nonlinear FBGs.
With growing demands of Internet Protocol services for transmission capacity and speed, the Optical Burst Switching
presents the solution for future high-speed optical networks. Optical Burst Switching is a technology for transmitting
large amounts of data bursts through a transparent optical switching network. To successfully transmit bursts over OBS
network and reach the destination node, resource reservation schemes have to be implemented to allocate resources and
configure optical switches for that burst at each node. The one-way resource reservation schemes and the performance
evaluation of reservation schemes are presented. The OBS network model is performed using OMNeT++ simulation
environment. During the reservation of network resources, the optical cross-connect based on semiconductor optical
amplifier is used as the core node. Optical switches based on semiconductor optical amplifiers are a promising
technology for high-speed optical communication networks.
The word soliton refers to a special kind of wave packets that can propagate undistorted over long distances. As a source for generating soliton pulses in 1990 erbium doped lasers were used. Soliton transmission systems have been the subject of interest for years. It is known that interaction and the balance between the dispersion and nonlinear effects in optical fibers can lead to a special pulse behavior. Soliton pulses can propagate without any changes of the amplitude and the shape via long transmission systems. Due to this advantage they are of interest in long haul communication systems. Here we describe how the random change of input pulse chirp in optical fibers can affect the soliton propagation and interaction between two or more solitons. We have focused on describing some numerical approaches to solve the coupled nonlinear Schrödinger equations, which are useful by solving this kind of problem. Most of laser sources can be approximated by Gaussian distribution or in special cases the second hyperbolic pulses are generated to produce a soliton shaped pulse. The effect of pulse chirp can generate new frequencies due to the frequency chirp. In high bitratetransmission systems this chirp is very important to reduce, because of this new frequency can influence the neighbor channels and lead to BER increasing.
Although nonlinear fiber Bragg gratings (FBGs) are well known devices more than three decades their using as all-optical switching elements is still investigated. Current research is focused on optimization their properties for their using in future all-optical networks. The main problem is minimizing of switching intensities needed for achieving the changes of transmission state. Switching intensities were over several years reduced from hundreds of GW/cm2 to tens of MW/cm2. Reduction of switching intensities can be achieved by selecting appropriate gratings and signal parameters or using suitable materials. This contribution is focused on nonlinear FBGs based on chalcogenide glasses which are very often used in various applications. Chalcogenide glasses thanks to their high nonlinear parameters are suitable candidates for reducing switching intensities of nonlinear FBGs.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.