1,800 research outputs found

    Photonic crystal chips for optical communications and quantum information processing

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    We discuss recent our recent progress on functional photonic crystals devices and circuits for classical and quantum information processing. For classical applications, we have demonstrated a room-temperature-operated, low threshold, nanocavity laser with pulse width in the picosecond regime; and an all-optical switch controlled with 60 fJ pulses that shows switching time on the order of tens of picoseconds. For quantum information processing, we discuss the promise of quantum networks on multifunctional photonic crystals chips. We also discuss a new coherent probing technique of quantum dots coupled to photonic crystal nanocavities and demonstrate amplitude and phase nonlinearities realized with control beams at the single photon level

    Photonic crystal chips for optical interconnects and quantum information processing

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    We have recently demonstrated a number of functional photonic crystals devices and circuits, including an ultrafast, room temperature, low threshold, nanocavity laser with the direct modulation speed approaching 1 THz, an all-optical switch controlled with 60 fJ pulses and with the speed exceeding 200Hz, and a local, reversible tuning of individual quantum dots on a photonic crystal chip by up to 1.8nm, which was then used to tune single quantum dots into strong coupling with a photonic crystal cavity and to achieve a giant optical nonlinearity

    Dynamics of Quantum Dot Photonic Crystal Lasers

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    Quantum dot photonic crystal membrane lasers were fabricated and the large signal modulation characteristics were studied. We find that the modulation characteristics of quantum dot lasers can be significantly improved using cavities with large spontaneous emission coupling factor. Our experiments show, and simulations confirm, that the modulation rate is limited by the rate of carrier capture into the dots to around 30GHz in our present system

    Does Landowner Awareness and Knowledge Lead to Sustainable Forest Management? A Vermont Case Study

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    Family forest owners control 40% of forestland in the United States. Timber harvesting on family forests represents a critical component of the nation\u27s wood supply. We examined how awareness and knowledge translated into actual forest management practices. We conducted field surveys on 59 family forest properties, coupled with a landowner survey designed to measure landowner engagement. We determined that engaged landowners implemented silviculture and Best Management Practices at a higher level than their less engaged counterparts. Improvement was needed across the board. Forestry Extension professionals should continue to promote and re-enforce awareness and knowledge among landowners

    Beyond Compliance: Empowering Employees’ Extra-Role Security Behaviors in Dynamic Environments

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    Information security policies are (ISP) used to guide employees in order to ensure information security while utilizing organizational information systems in the workplace. However, rigid compliance with ISP may not help employees and companies to confront emerging threats in the dynamic environment of modern security threats. ISP should be developed and improved according to the demands of implementers and in keeping with the changing security environment. To that end, we propose that employees\u27 extra-role behaviors - actions that may seem to go beyond requirements and limitations of security policies - can provide input into forming suitable and feasible security policies that provide insights against the emerging threats in the operating environment

    Effects of the microsporidium Nosema adaliae from Adalia bipunctata L. on the multicoloured Asian lady beetle Harmonia axyridis Pallas

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    1 online resource (iv, 20 p.)Includes abstract.Includes bibliographical references (p. 16-20).Originally imported for use as a biological control agent for pest insects, the multicoloured Asian lady beetle Harmonia axyridis has itself become a pest in many areas. While it is a very successful biological control, it has many non-target impacts such as displacement of native species of lady beetles and it can have adverse effects on human health. The geographic distribution of H. axyridis in Nova Scotia overlaps with the range of the native two-spotted lady beetle, Adalia bipunctata. This overlap provides the opportunity for the microsporidian pathogen Nosema adaliae to be horizontally transmitted to H. axyridis. In this study, H. axyridis larvae were allowed to consume a mixture of uninfected and infected A. bipunctata eggs. All H. axyridis larvae that consumed infected eggs were infected by the pathogen. Larval development was significantly prolonged for those larvae that consumed four infected eggs. These results suggest that H. axyridis has some resistance to the effects of N. adaliae since it requires the consumption of four infected eggs to significantly delay larval development
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