Abstract:We demonstrate that a distributed Raman amplification scheme based on random distributed feedback (DFB) fiber laser enables bidirectional second-order Raman pumping without increasing relative intensity noise (RIN) of the signal. This extends the reach of 10×116 Gb/s DP-QPSK WDM transmission up to 7915 km, compared with conventional Raman amplification schemes. Moreover, this scheme gives the longest maximum transmission distance among all the Raman amplification schemes presented in this paper, whilst maintaining relatively uniform and symmetric signal power distribution, and is also adjustable in order to be highly compatible with different nonlinearity compensation techniques, including mid-link optical phase conjugation (OPC) and nonlinear Fourier transform (NFT). 2015 Optical Society of America

In this paper, we experimentally demonstrate the benefit of polarization insensitive dual-band optical phase conjugation for up to ten 400Gbit/s optical super-channels using a Raman amplified transmission link with a realistic span length of 75km. We demonstrate that the resultant increase in transmission distance may be predicted analytically if the detrimental impacts of power asymmetry and polarization mode dispersion are taken into account.

Abstract:The UBC Brock Commons building in Vancouver, which comprises of 18 stories and stands 53 m in height, was at the time of completion in 2016 the world's tallest hybrid wood-based building. The building's 17 stories of mass-timber superstructure, carrying all gravity loads, rest on a concrete podium with two concrete cores that act as both the wind and seismic lateral load-resisting systems. Whereas the construction of the concrete cores took fourteen weeks in time, the mass-timber superstructure took only ten weeks from initiation to completion. A substantial reduction in the project timeline could have been achieved if mass-timber had been used for the cores, leading to a further reduction of the building's environmental footprint and potential cost savings. The objective of this research was to evaluate the possibility of designing the UBC Brock Commons building using mass-timber cores. The results from a validated numerical structural model indicate that applying a series of structural adjustments, that is, configuration and thickness of cores, solutions with mass-timber cores can meet the seismic and wind performance criteria as per the current National Building Code of Canada. Specifically, the findings suggest the adoption of laminated-veneer lumber cores with supplementary 'C-shaped' walls to reduce torsion and optimize section's mechanical properties. Furthermore, a life cycle analysis showed the environmental benefit of these all-wood solutions.

An effective way of increasing the overall optical fibre capacity is by expanding the bandwidth used to transmit signals. In this paper, the impact of expanding the transmission bandwidth on the optical communication system is experimentally studied using the achievable rates as a performance metric. The tradeoffs between the use of larger bandwidths and higher nonlinear interference (NLI) noise is experimentally and theoretically analyzed. The growth of NLI noise is investigated for spectral bandwidths from 40 GHz up to 7.3 THz using 64-QAM and Nyquist pulse-shaping. Experimental results are shown to be in line with the predictions from the Gaussian-noise model showing a logarithmic growth in NLI noise as the signal bandwidth is extended. A reduction of the information rate of only 10% was found between linear and nonlinear transmission across several transmission bandwidths, increasing up to 7.3 THz. Finally, the power transfer between channels due to stimulated Raman scattering effect is analyzed showing up to 2-dB power tilt at optimum power for the largest transmitted bandwidth of 7.3 THz. Index Terms-GN model, nonlinear effects, optical fibre, optical fibre communications. I. INTRODUCTION O PTICAL fibres are the fundamental transmission medium for modern communication systems. Among their most attractive features they present a low-loss region that spans tens of terahertz. To increase the amount of information transmitted over optical fibres, much research effort has been focused on extending the usable spectrum beyond the conventional C-band,

In this work, we will derive, validate, and analyze the theoretical description of nonlinear Kerr effects resulting from various transmission systems that deploy single or multiple optical phase conjugators (OPCs). We will show that the nonlinear Kerr compensation can be achieved, with various efficiencies, in both lumped and distributed Raman transmission systems. The results show that first order distributed Raman systems are superior to the discretely amplified systems in terms of the nonlinear Kerr compensation efficiency that a mid-link OPC can achieve. Also, we will show that the multi-OPC approach will diminish the nonlinearity compensation efficiency in any system as it will act as periodic dispersion compensators.