Optimal Higher-order Dispersion Management Methods in WDM Transmission Systems

In order to reduce the four-wave mixing crosstalk and avoid the signal waveform distortion in long-haul dense-wavelength division multiplexing systems,helpful methods on how to choose suitable local parameters in higher-order dispersion managed line are presented, which are used to increase the system capacity and improve the system performances.

Dispersion management for a 100 PW level laser using a mismatched-grating compressor

We report dispersion management based on a mismatched-grating compressor for a 100 PW level laser,which utilizes optical parametric chirped pulse amplification and also features large chirped pulse duration and an ultra-broadband spectrum.The numerical calculation indicates that amplified pulses with 4 ns chirped pulse duration and 210 nm spectral bandwidth can be directly compressed to sub-13 fs,which is close to the Fourier-transform limit(FTL).More importantly,the tolerances of the mismatched-grating compressor to the misalignment of the stretcher,the error of the desired grating groove density and the variation of material dispersion are comprehensively analyzed,which is crucially important for its practical application.The results demonstrate that good tolerances and near-FTL compressed pulses can be achieved simultaneously,just by keeping a balance between the residual second-,third-and fourth-order dispersions in the laser system.This work can offer a meaningful guideline for the design and construction of 100 PW level lasers.

Dispersion Management with Higher Order Mode Fibers

Dispersion compensation with few-mode fibers is emerging as a promising technique that can provide full dispersion and dispersion-slope compensation. The inherent modal path diversity of these fibers allows implementation of static as well as tunable dispersion management schemes. In addition, the low non-linearity of this technology can improve system OSNR, leading to enhancements in transmission distances.

Stable error-free single channel 160-Gb/s OTDM 100-km transmission via high-precision dispersion management

A single channel with a 160-Gb/s optical time-division-multiplexing （OTDM） transmission over 100 km is fabricated. With the help of 500-GHz optical sampling oscilloscopes, the fiber length is adjusted to the order of 10 m, which corresponds to the accuracy of 0.4 ps for the dispersion compensation. The dispersion map is optimized for the 100-km transmission link. A completely error-free transmission with the power penalty of 3.6 dB is achieved for 2 h without using forward error correction.

Dispersion Properties in Total Internal Reflective Photonic Crystal Fiber

The dispersion properties in the short wavelength region of total internal reflective photonic crystal fiber have been studied by using the models of the equivalent twin waveguide soliton coupling,effective refractive index,effective normalized frequency and dispersion management solitons.It is shown that the dispersion in the cladding waveguide of the total internal reflective photonic crystal fiber is a positive dispersion,and the dispersion of its core waveguide is a negative dispersion.The method of the compensated probing laser diffraction by the phase hole induced by the stationary pumping laser in the cladding waveguide enables the average dispersion value of the total internal reflective photonic crystal fiber to be close to zero and the zero dispersion point to shift to the short wavelength region.

Nonlinear Interactions of Dispersion-managed Soliton in OTDM Systems

The dispersion-managed soliton (DMS) transmission model of dispersion-managed systems is established,and the intrachannel DMS interactions equation is obtained.The impact of soliton interactions on DMS systems are numerically investigated.Finally,the relationships of the collision length changing with map strength are revealed.

Management and Control of Outsourcing in Dispersed Network Manufacturing Systems

The trend of economic globalisation and advances in i nformation technology has led to the emergence of dispersed manufacturing system s as a form of the virtual organisation. New manufacturing strategy pays more at tention to the management of the total value chain and therefore puts emphasis o n outsourcing. In fact, outsourcing is an efficient way of utilizing available r esources and has become one key aspect of the manufacturing strategy. Improved d ecision and organization on outsourcing will result in cost production and short er lead-times. However, most concepts and practice of traditional outsourcing do not adapt to t he changing environment and meet increasing performance requirements. On the oth er hand, virtual organisations might display instability between pure outsourcin g and establishing alliance. Balance and trade-off between independent agents a nd creating alliance are thus required. Therefore, the purpose of this paper is to develop a model to support decision-making, management and control on outsou rcing in a dispersed network manufacturing system and to discuss several key iss ues that are relevant to the relationship between the agents of the network. Dev elopment of the model will deploy Applied System Theory and will be built on fou ndations of earlier research on industrial management such the theories of Outso urcing, Order Entry Points, Design of Organisations and Logistic Control. The is sues that will be addressed in this paper are: · The selection of suppliers and co-makers; · Communication between suppliers and clients; · The mechanisms for profit-sharing between agents; · The product data management to integrate the knowledge of the different agent s into product design. Industrial companies will benefit from this research by the practical methods an d implementation extending their business models beyond concepts for outsourcing and alliances. Additionally, the exploration will lead to proactive contributio n of manufacturing during engineering, which would improve management and contro l of dispersed manufacturing systems.

Numerical Integrators for Dispersion-Managed KdV Equation

In this paper,we consider the numerics of the dispersion-managed Kortewegde Vries(DM-KdV)equation for describingwave propagations in inhomogeneous media.The DM-KdV equation contains a variable dispersion map with discontinuity,which makes the solution non-smooth in time.We formally analyze the convergence order reduction problems of some popular numerical methods including finite difference and time-splitting for solving the DM-KdV equation,where a necessary constraint on the time step has been identified.Then,two exponential-type dispersionmap integrators up to second order accuracy are derived,which are efficiently incorporatedwith the Fourier pseudospectral discretization in space,and they can converge regardless the discontinuity and the step size.Numerical comparisons show the advantage of the proposed methods with the application to solitary wave dynamics and extension to the fast&strong dispersion-management regime.

The characters of dense dispersion managed soliton in optical fiber transmission systems

The properties of ultra-short dense dispersion-managed soliton (DBMS) in optical fiber links are investigated. They show some excellent characters, such as, reducing pulse's breathing extent greatly, facing fewer mutual interactions and tolerating larger local dispersion. In general, DBMS is more stable than a conventional dispersion-managed soliton in high-capacity systems. Excessively dense dispersion compensation is more suitable for systems with weak nonlinear effect.

Filter control polarization mode dispersion in dispersion managed soliton systems

In this paper, the dispersion managed soliton (DMS) transmission equation is built on considering the effects of polarization mode dispersion (PMD) and filter control. The DMS transmission of filtering control in constant birefringence fibers is firstly analyzed by varitional method, from which the evolving rules of characteristical DMS parameters are obtained. Secondly, the stability of DMS transmission and its timing jitter are investigated in the random varying birefringence fibers with the conventional model of PMD. The results reveal that filter control DMS system has powerful robustness to PMD effects and DMS's timing jitter can be decreased considerably with the help of filters.

Mode-locked 2.8-μm fluoride fiber laser:from soliton to breathing pulse

The mode-locked fluoride fiber laser(MLFFL)is an exciting platform for directly generating ultrashort pulses in the mid-infrared(mid-IR).However,owing to difficulty in managing the dispersion in fluoride fiber lasers,MLFFLs are restricted to the soliton regime,hindering pulse-energy scaling.We overcame the problem of dispersion management by utilizing the huge normal dispersion generated near the absorption edge of an infrared-bandgap semiconductor and promoted MLFFL from soliton to breathing-pulse mode-locking.In the breathing-pulse regime,the accumulated nonlinear phase shift can be significantly reduced in the cavity,and the pulse-energy-limitation effect is mitigated.The breathing-pulse MLFFL directly produced a pulse energy of 9.3 nJ and pulse duration of 215 fs,with a record peak power of 43.3 kW at 2.8μm.Our work paves the way for the pulse-energy and peak-power scaling of mid-IR fluoride fiber lasers,enabling a wide range of applications.

Frontier research of ultra-high-speed ultra-large-capacity and ultra-long-haul optical transmission

Ultra-high-speed, ultra-large-capacity and ultra-long-haul （3U） are the forever pursuit of optical communication. As a new mode of optical communication, 3U transmission can greatly promote next generation optical internet and broadband mobile communication network development and technological progress, therefore it has become the focus of international high-tech intellectual property competition ground. This paper introduces the scientific problems, key technologies and important achievements in 3U transmission research.