Optimum architecture for input queuing ATM switches

Crossconnects. We analyzed here the add drop multiplexing system for multiple wavelength channels, different condition of channel presence and channel separation. We simulate the crosstalk power, signal-to crosstalk ratio (SCR) and bit error rate (BER) of the system with different number of channels presence. Here we compared crosstalk power and SCR for multiple wavelength channels like 4, 8, 16, 32 channels considering different channel separation and drop of channels from the system. It is found that the SCR increases with the channel separation and SCR decreases with increase of the channel Bandwidth (B). BER increases with the number of wavelength channels due to increased in amount of crosstalk.

Journal of Lightwave Technology, 1996

transport via cascaded optical components transport via fibre wDMA/subcarrier pDh4A broadmt and 1943 multiple discrete reflections [5-91 Rayleigh backscatter [lo-131 beating between subcarrier [14-16] channels at the same h Solution Paths to Limit Interferometric Noise Induced Performance Degradation in signal processors space switches WDM transport network AS WDirect Detection Lightwave Networks coupler switch crosstalk t201 switch crosstalk [21-23]

Journal of Lightwave Technology, 2000

This paper describes and analyzes a particular application of high duty-cycle time-division multiplexing to the separation and identification of signals from an interferometric sensor array. Using the method discussed here, the coherence length of the laser is no longer a severe design constraint. Also, the source phase-induced intensity noise which limits some other multiplexing methods may be overcome, leading to a higher sensitivity. The arrays of all-passive remote sensors exhibit minimal crosstalk between sensors, and have downlead insensitivity. A synthetic heterodyne demodulation technique prevents environmentally induced signal fading. Analysis includes coupling ratios for all directional couplers in the system, signal and noise spectra, minimum detectable phase shift, and the effect of ac coupling on noise and crosstalk. An experimental all-fiber implementation of a two sensor array has yielded a measured sensitivity of approximately 10 prad/& over a range of signal frequencies, and a crosstalk level of better than 55 dB.

Journal of Lightwave Technology, 1999

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IEEE/OSA Journal of Lightwave Technology, 2002

The effect of in-band crosstalk can pose severe limitations in an optical network. In this paper, the implications of in-band crosstalk induced by an arrayed waveguide grating router, in a passive NxN optical interconnection, are analyzed with non Gaussian statistics using a numerical model. The model is based on the saddle point approximation and takes into account the fluctuations of the transfer function's sidelobes induced by the phase errors in the grating arms, phase noise, polarization variations, bit misalignment, shot and thermal noise. The influence of the above effects on the interconnection's BER is analyzed. The validity of the Gaussian assumption for the crosstalk noise statistics is discussed. Finally, the model is used to examine the mean crosstalk requirements for various numbers of network nodes. Arrayed Waveguide Gratings [1],[2] (AWGs) are important components for the realization of modern optical Wavelength Division Multiplexing (WDM) [3] networks on which they can serve as multiplexers, demultiplexers and wavelength routers. Devices of this kind have been made commercially available and there are techniques that allow polarization insensitive operation [4]. However, due to fabrication imperfections, AWGs suffer from phase errors [5],[6], which tend to create sidelobes outside the main lobe of their transfer function, making the separation of the wavelength channels non-ideal. In a network with wavelength reuse, this can lead to in-band crosstalk noise (which is on the same wavelength as that of the signal) as well as out-of-band crosstalk noise (which is on different wavelength) [7]. Out-of-band crosstalk can be removed with additional filtering at the receiver side but in-band crosstalk can not be removed and can increase significantly the Bit Error Rate (BER) of the received signal. In the network considered in this paper, in-band crosstalk originates from different LASER sources at different network nodes. As a result the noise components and the signal will be considered statistically independent of each other. Many studies have been made in order to understand the implications of in-band crosstalk in an optical network (see [8]-[11] and references therein). In the case of many independent, identically distributed (IID) interferers, its Probability Density Function (PDF) can be assumed approximately Gaussian because of the Central Limit Theorem (CLT). The Gaussian approximation has also been used for the estimation of the performance of a NxN AWG interconnection [8] where the interferers are not of equal power. Although the CLT is still valid in this case, the Gaussian model may not provide

IEEE Photonics Technology Letters, 2003

IEEE Photonics Technology Letters, 2000

We report the first experimental demonstration of using wavelength-division-multiplexing and wavelength-selectivedetection to facilitate either reconfigurable or simultaneous optical interconnections between one source plane and many detector planes. We show the lo-' BER, 155 Mb/s transmission and detection of three different wavelength-multiplexed signals at three detector planes. The reconfigurable interconnection is established with a wavelength separation of 10 nm, and the simultaneous interconnection is established with a wavelength separation of 43 nm.

IEEE Journal on Selected Areas in Communications, 1990

Abstmct-The fabrication and operation of a monolithically integrated InGaAsP/lnP WDM detector chip is reported. It consists of a Y-branch grating demultiplexer and two p-i-n photodiodes. Polarization-independent operation for two closely spaced channels ( A X = 3.6 nm) at X = 1.5 pm was obtained. The dark current (2-10 nA) and the bandwidth (420 MHz) of the photodiodes are sufficient to transmit broad-band services.

OFC/IOOC . Technical Digest. Optical Fiber Communication Conference, 1999, and the International Conference on Integrated Optics and Optical Fiber Communication

Iee Proceedings J Optoelectronics, 1986

Preliminary results are presented from an analysis of the intermodulation behavior of guide wave acoustooptic devices (GWAOD). The analysis indicates that the largest dynamic range available from GWAODs will be 27 dB with a 10 percent efficiency, although gains may be made by reducing the occurrences of in-plane scattering. The intermodulation effects occurring in the case of two equal strength signals at neighboring frequencies are reported in terms of the diffracted light intensity as a function of the input electrical power. The tests illustrated the linearity of the responses, which is predicted by current theory. Various recommendations are provided for further research in order to move the technology of GWOADs from the laboratory to practical usage at higher power levels and with controlled thermal effects.

Optical Sensors 2011; and Photonic Crystal Fibers V, 2011

In this paper an edge filter based on multimode interference in an integrated waveguide is optimized for a wavelength monitoring application. This can also be used as a demodulation element in a fibre Bragg grating sensing system. A global optimization algorithm is presented for the optimum design of the multimode interference device, including a range of parameters of the multimode waveguide, such as length, width and position of the input and output waveguides. The designed structure demonstrates the desired spectral response for wavelength measurements. Fabrication tolerance is also analysed numerically for this structure.

Optics Express, 2015

A novel photonic integrated circuit is proposed that, using an RF source, generates at its output ports the same magnitude but opposite sign high order single optical side bands of a suppressed optical carrier. A single stage parallel Mach-Zehnder Modulator (MZM) and a two-stage series parallel MZM architecture are described and their relative merits discussed. A transfer matrix method is used to describe the operation of the circuits. The theoretical analysis is validated by computer simulation. As an illustration of a prospective application, it is shown how the circuit may be used as a key element of an optical transmission system to transport radio signals over fibre for wireless access; generating remotely a mm-wave carrier modulated by digital IQ data. A detailed calculation of symbol error rate is presented to characterise the system performance. The circuit may be fabricated in any integration platform offering a suitable phase modulator circuit element such as LiNbO3, Silicon, and III-V or hybrid technology.

Proceedings of 2001 3rd International Conference on Transparent Optical Networks (IEEE Cat. No.01EX488), 2001

The side mode suppression ratio of self-seeded, gain-switched optical pulses is shown to be a vital parameter in wavelength division multiplexed communications systems. Experiments carried out on a 2-channel wavelength multiplexed set-up using tunable self-seeded gain-switched pulse sources at 2.5 GHz, have demonstrated the cross-channel interference effects which may be encountered if the side mode suppression ratio of one of the sources becomes degraded.

Electronics Letters, 1998

The high dense WDM system is used with bandwidth utilization using high data rates and low channel spacing. But the in High dense WDM system because of high data rates the channel interference occurs and due to which crosstalk occurs and the signal get distorts. To avoid such problems we can use fiber bragg grating filter. The high data rates range is minimum 2.5 Gbits/s to maximum 40 Gbits/s for channel spacing 200Ghz, 100Ghz, 50 Ghz, 25 GHz for this paper. We used minimum data rate 2.5 Gbits/s and maximum data rates 10.52 Gbits/s for low channel spacing. We carried two simulation using simulation software optisystem 10.0 for haigh data rates and low channel spacing to get higher channel isolation in High dense WDM system. To get high channel isolation we use FBG filter which includes three different apodization profile like uniform apodization profile, Gaussian apodization profile and Tanh (hyperbolic Tangent) profile. In first simulation we used single FBG filter including all these three apodization profile and in second simulation we used two FBG filter including all these three apodization profile in which Gaussian apodization profile is best for 10.52 Gbits/s data rates for 100 Ghz channel spacing.