Abstract

Abstract

Abstract
We show that optical shock-wave solutions are possible in nonlinear dispersive amplifying media that exhibit a frequency-dependent gain and background loss. These shock-wave domains exist at lasing threshold and are permitted in both the normal and the anomalous dispersive regions.

Abstract
By means of an exact solution, we demonstrate that a Gaussian beam can undergo spatial compression when it traverses a photorefractive medium. This is possible provided that the external bias field exceeds the critical value necessary to establish photorefractive spatial solitons. In this regime and under paraxial assumptions our analysis indicates that a Gaussian beam tends to exhibit self-focusing collapse. Beam self-deflection effects that arise from the pi/2-phase-shifted component of the photorefractive grating are also considered in our study.

Abstract
BST is a well established standard and testability framework for digital ICs and boards. The paper presents a test support IC controlled by an IEEE1149.1 interface, capable of providing access to analog nodes in mixed-signal boards. The proposed architecture (ABSINT - Analog to Boundary Scan Interface) is described and relevant implementation issues are discussed. A demonstrator IC implementing the ABSINT architecture is presented, and it is shown how it can be used to provide analog test channels under control of IEEE1149.1.

Abstract
The performance of frequency-modulated (FM) subcarrier-multiplexed systems is assessed using Volterra series analysis to model laser nonlinear distortion accurately. The intermodulation-power spectral density and the carrier-to-intermodulation ratio are then determined. The performance of these systems is investigated by considering all noise contributions: intermodulation and relative intensity noise in the transmitter and receiver thermal and shot noise. Optimum performance is also identified. A 62-channel FM video system occupying the bandwidth of 2.7-5.2 GHz provides an illustrative example.