Ion-Exchanged Glass Waveguides with Low Birefringence for a Broad Range of Waveguide Widths

Optical communications networks require integrated photonic components with negligible polarization dependence, which typically means that the waveguides must feature very low birefringence. Recent studies have shown that waveguides with low birefringence can be obtained, e.g., by use of silica-on-silicon waveguides or buried ion-exchanged glass waveguides. However, many integrated photonic circuits consist of waveguides with varying widths. Therefore low birefringence is consequently required for waveguides having different widths. This is a difficult task for most waveguide fabrication technologies. We present experimental results on waveguide birefringence for buried silver–sodium ion-exchanged glass waveguides. We show that the waveguide birefringence of the order of 106 for waveguide mask opening widths ranging from 2 to 10 μm can be obtained by postprocessing the sample through annealing at an elevated temperature. The measured values are in agreement with the values calculated with our modeling software for ion-exchanged glass waveguides. This unique feature of ion-exchanged waveguides may be of significant importance in a wide variety of integrated photonic circuits requiring polarization independent operation

SECURE AND RELIABLE POWER SUPPLY WITH CHALLENGES- SMART GRID

Smart Grid implementations will certainly increase the quantity, quality and use of information available from advanced sensing, computing and communications hardware as well as software. There is virtually universal agreement that it is necessary to upgrade the electric grid to increase overall system efficiency and reliability. Many technologies currently in use by the grid is outdated and in many cases unreliable. The reliance on old technology leads to inefficient systems, costing unnecessary money to the utilities, consumers and taxpayers. To upgrade the grid and to operate an improved grid will require significant dependence on distributed intelligence and broadband communication capabilities. The access and communications capabilities require the latest in security technology which are reliable for extremely large, wide-area communications networks. This paper discusses features, reasons of development, barriers and their solutions for a smart grid system

UK energy in a global context: synthesis report

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A one-step procedure to probe the viscoelastic properties of cells by Atomic Force Microscopy

The increasingly recognised importance of viscoelastic properties of cells in pathological conditions requires rapid development of advanced cell microrheology technologies. Here, we present a novel Atomic Force Microscopy (AFM)-microrheology (AFM2) method for measuring the viscoelastic properties in living cells, over a wide range of continuous frequencies (0.005 Hz ~ 200 Hz), from a simple stress-relaxation nanoindentation. Experimental data were directly analysed without the need for pre-conceived viscoelastic models. We show the method had an excellent agreement with conventional oscillatory bulk-rheology measurements in gels, opening a new avenue for viscoelastic characterisation of soft matter using minute quantity of materials (or cells). Using this capability, we investigate the viscoelastic responses of cells in association with cancer cell invasive activity modulated by two important molecular regulators (i.e. mutation of the p53 gene and Rho kinase activity). The analysis of elastic (G′(ω)) and viscous (G″(ω)) moduli of living cells has led to the discovery of a characteristic transitions of the loss tangent (G″(ω)/G′(ω)) in the low frequency range (0.005 Hz ~ 0.1 Hz) that is indicative of the capability for cell restructuring of F-actin network. Our method is ready to be implemented in conventional AFMs, providing a simple yet powerful tool for measuring the viscoelastic properties of living cells

Keeping the LEDs on and the Electric Motors Running: Clean Tech in Court After Ebay

The recent rise of non-practicing patentees (NPPs) in the clean technology space comes at a time when the international community is debating the role of intellectual property rights in the deployment and implementation of technologies to combat climate change. While the impact of intellectual property rights on the deployment of clean technology has been studied, less attention has been given to the role intellectual property regimes play in maintaining the operation of those technologies already deployed in the fight against global warming. This iBrief focuses on clean technologies that have already achieved substantial market penetration and observes that recent trends in patent law are, to a large extent, allowing those technologies to continue working to reduce carbon emissions. Specifically, the course correction in the law of patent injunctions brought about by eBay v. MercExchange and the endorsement of court-imposed ongoing royalty payments in Paice v. Toyota demonstrate an important shift in patent law that is tempering the impact of clean tech NPPs in Title 35 infringement actions in federal courts. However, these trends have caused a tactical adjustment by clean tech NPPs—namely, filing suits in the U.S. International Trade Commission (ITC), where the remedy of an exclusion order is available. These ITC cases could adversely affect implemented clean technologies

IE WP 23/04 Prospective Voluntary Agreements to Escape Carbon Lock-in

The paper looks for co-evolutionary policy responses to carbon lock-in – a persistent state that creates systemic market and policy barriers to carbon low technological alternatives. We address the coordination role for authorities rather than the corrective optimisation and analyse experiences from environmental voluntary agreements and foresight activities. The paper argues that combining the virtues of these tools into a new policy tool, named Prospective Voluntary Agreement (PVA), can help facilitate an escape from carbon lock-in and provide policy resources for addressing lock-in related issues. The merit of PVA lies with the enhancement of collaborative policy culture and inter-sectoral and interdisciplinary stakeholder learning that creates commitment to desired action for escaping lock-in.environmental voluntary agreement; foresight; increasing returns; lock-in; path-dependence