102,408 research outputs found
Design and performances of logarithmic wavelength demultiplexers
No full textWe investigate the performance and furnish design guideline for a 1×N router realized as a tree of Mach-Zehnder interferometers, with free-spectral ranges that follow a logarithmic progression. We show that the crosstalk can be reduced and the channel passband flattened by inserting all-pass (AP) filters in the interferometers arms, with a suitable choice of the coupling ratios. The proposed device is inherently low loss and the chromatic dispersion introduced by the AP filters can be easily compensated. Two different realizations are investigated, and the power penalties induced by losses and dispersion are evaluated numerically
OCDM systems with PSK and QAM codes
No full textA multiport encoder/decoder can simultaneously generate multiple PSK optical codes, and it has been effectively used in asynchronous, spectrally efficient access networks. To increase the system flexibility, as well as the number of simultaneous IoT signals, we introduce novel multi-level QAM orthogonal optical codes that are generated by the multiport encoder/decoder using optical phase modulators. The QPSK modulator simultaneously operates for data modulation and orthogonal code generation. The code orthogonality is improved, compared to conventional PSK codes, and we analyze the performance of 16-code × 10 GSymbol/s, OOK-, DPSK- and DQPSK-modulated OCDM systems, using conventional PSK and the proposed QAM codes
Designing Industrial Sustainability Policies in the Agent- Based Macro-Economic Framework EURACE
No full textEvidence increasingly suggests that the industrial system is a large contributor to anthropogenic
climate change, is increasingly creating resource scarcity, and is generating unmanageable waste
to land-fill. To develop more sustainable industrial systems and sustainable societies, policy
makers and industry need to better understand how to transform industrial behaviour leveraging
on appropriate investment and implementation of technology. The phenomena to be studied
originate in classical economic externalities. In recent years, a bottom-up approach to economic
analysis, referred to as “agent-based modeling,” has been motivated by new insights on the
limitations of traditional economic approaches, as well as computational advances. The key
advantage of agent based modeling in this context is to explicitly treat the incentives that face
behaviorally realistic agents in empirically credible environments and its ability to take into
account behavioural heterogeneity and interactions, which can lead to emergent behaviour which
might be very difficult to foresee in an aggregate model.
We employ the EURACE agent based macro-economic model and simulator (Cincotti et al., 2010,
Raberto et al. 2012) and enrich it to encompass industrial sustainability considerations. In
particular, we endow the firms’ production function with an additional raw material input
(provided by the environmental agent at costs rising with the demand), and with an additional
output representing the creation of waste/emissions. The fiscal policy of the government agent is
also enriched to include possible fiscal incentives to the industry to support investment in ecoproductivity
enhancement to avoid potential future obligations to pay for mitigation/adaptation to
address negative environmental impacts of industry. Preliminary computational experiments show
non trivial complex behaviros, where the fiscal incentives to the sustainable transition may have
different macroeconomic and environmental outcomes, depending on both the business cycles
and the size of the rebound effect of the improved technology.
The contribution of this work is then to initiate a new research field into the use of an agent-based
macro-economic framework for investigating industrial sustainability and to assist policy makers
by providing a framework to better assess policy options for investments and incentive systems to
drive sustainability
Diffractive variable beam splitter: optimal design
No full textThe analytical expression of the phase profile of the optimum diffractive beam splitter with an arbitrary power ratio between the two output beams is derived. The phase function is obtained by an analytical optimization procedure such that the diffraction efficiency of the resulting optical element is the highest for an actual device. Comparisons are presented with the efficiency of a diffractive beam splitter specified by a sawtooth phase function and with the pertinent theoretical upper bound for this type of element
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