Effects of pattern dependence on high-power polarization-division-multiplexing applications

High-power polarization-division-multiplexing (PDM) systems or functional modules, such as self-phase-modulation (SPM)-based all-optical regenerators, cross-phase-modulation (XPM)-based wavelength convertors or format convertors, all-optical logical gate, and so on, may suffer from the effects of pattern dependence. Such effects are experimentally investigated using relative time delay variation between bit sequences with orthogonal polarization states in a 2 × 10.65 Gb/s high-power on-off keying (OOK) PDM system. Eye-diagram-based signal-to-noise ratio (SNR) and bandwidth of broadened spectrum are measured and compared. An eye-diagram-based SNR fluctuation of up to 4 dB may occur as the delay changes.     

About Thinning Invariant Partition Structures

Bernoulli-p thinning has been well-studied for point processes. Here we consider three other cases: (1) sequences (X ₁,X ₂,??); (2) gaps of such sequences (X _n+1?X ₁) _n???; (3) partition structures. For the first case we characterize the distributions which are simultaneously invariant under Bernoulli-p thinning for all p??(0,1]. Based on this, we make conjectures for the latter two cases, and provide a potential approach for proof. We explain the relation to spin glasses, which is complementary to important previous work of Aizenman and Ruzmaikina, Arguin, and Shkolnikov.     

Classification of extensions of torus algebra II

We use extension theory and algebraic methods to give a complete characterization of extensions of torus algebra by stable Cuntz algebras,and prove certain classification theorems of these extension algebras.     

Effect of atmospheric parameters on fine particulate concentration in suburban Shanghai

A study was conducted on the effect of atmospheric parameters,including temperature,wind speed,and relative humidity,on fine particulate mass concentrations measured in Jiading District of Shanghai,China, during the period from January 2009 to January 2010.A sensitivity analysis was applied to investigate the interaction between atmospheric parameters and particulate mass concentration.The experiment revealed that the concentration of particulates increased with particle size from 0.1 to 1.0μm,and decreased with the increase of particle size from 1.0 to 2.5μm.The effects of atmospheric parameters on fine mass concentrations were significantly particle size-dependent.The PM_1.0-2.5 may come from the size increase of smaller particulates after moisture absorption.And the variation of concentrations of PM_0.1-1.0 was mainly attributed to the accumulation of PM_0.1.The ventilation index and dilution index were calculated on the basis of data collected in December 2009.A correlation analysis indicated that there was a significant relation between these two indexes and the particulate concentration by examining the three particle size ranges,0.0-0.1,0.1-1.0,and 1.0-2.5μm.The Spearman correlation coefficients that related the ventilation index to the concentration for the three particle size ranges were -0.45,-0.56 and -0.47, respectively,while the coefficients that related the dilution index to the concentration were -0.36,-0.42 and -0.45,respectively.     

LOCALIZED PATTERNS OF THE CUBIC-QUINTIC SWIFT-HOHENBERG EQUATIONS WITH TWO SYMMETRY-BREAKING TERMS

Homoclinic snake always refers to the branches of homoclinic orbits \mbox{near} a heteroclinic cycle connecting a hyperbolic or non-hyperbolic equilibrium and a periodic orbit in a reversible variational system. In this paper, the normal form of a Swift-Hohenberg equation with two different symmetry-breaking terms (non-reversible term and non-k-symmetry term) are investigated by using multiple scale method, and their bifurcation diagrams are initially studied by numerical simulations. Typically, we predict numerically the existence of so-called round-snakes and round-isolas upon particular two symmetric-breaking perturbations.     

Compact beam expander based on planar structure to avoid inner focus

Optical Review - Based on the planar optical theory, compact beam expanders are proposed to miniaturize the dimension of an optical system. Both simulated and experimental results have demonstrated...