Depolarization remote sensing by orthogonality breaking

A new concept devoted to sensing the depolarization strength of materials from a single measurement is proposed and successfully validated on a variety of samples. It relies on the measurement of the orthogonality breaking between two orthogonal states of polarization after interaction with the material to be characterized. The two fields orthogonality being preserved after propagation in birefringent media, this concept is shown to be perfectly suited to depolarization remote sensing through fibers, opening the way to real time depolarization endoscopy.Comment: 5 pages, 4 figure

S-Restricted Compositions Revisited

An S-restricted composition of a positive integer n is an ordered partition of n where each summand is drawn from a given subset S of positive integers. There are various problems regarding such compositions which have received attention in recent years. This paper is an attempt at finding a closed- form formula for the number of S-restricted compositions of n. To do so, we reduce the problem to finding solutions to corresponding so-called interpreters which are linear homogeneous recurrence relations with constant coefficients. Then, we reduce interpreters to Diophantine equations. Such equations are not in general solvable. Thus, we restrict our attention to those S-restricted composition problems whose interpreters have a small number of coefficients, thereby leading to solvable Diophantine equations. The formalism developed is then used to study the integer sequences related to some well-known cases of the S-restricted composition problem

All photonic analogue to digital and digital to analogue conversion techniques for digital radio over fibre system applications

Copyright @ 2011 IEEEWideband electronic analogue to digital conversion (ADC) systems have critical problems encountered in high-frequency broadband communication systems that the recent electronic ADCs (EADC) have experienced those such as uncertainty of sampling time. In this paper, an all photonic sampling and quantization ADC and photonic digital to analogue conversion system with six effective number of bits (ENOB) is designed. By using this photonic ADC (PADC), a novel digital radio over fibre link for wireless radio frequency (RF) signal transportation over 20 Km single mode fibre has been designed whose performance is investigated in this paper. In the digital radio over fibre, the dynamic range is independent of the fibre length