High-Q optical resonators in silicon-on-insulator-based slot waveguides

This letter describes the design, fabrication and characterization of high-Q oval resonators based on slot waveguide geometries in thin silicon-on-insulator material. Optical quality factors of up to 27 000 were measured in such filters, and we estimate losses of –10 dB/cm in the slotted waveguides on the basis of our resonator measurements. Such waveguides enable the concentration of light to very high optical fields within nanoscale dimensions, and show promise for the confinement of light in low-index material with potential applications for optical modulation, nonlinear optics and optical sensing

High-Q ring resonators in thin silicon-on-insulator

We have fabricated high-Q microrings from thin silicon-on-insulater SOI layers and measured Q values of 45 000 in these rings, which were then improved to 57 000 by adding a PMMA cladding. The optimal waveguide designs were calculated, and the waveguide losses were analyzed. These high-Q resonators are expected to lead to interesting devices for telecommunication filters and sources as well as optical refractive index sensing

Integrated plasmon and dielectric waveguides

We have designed, fabricated and characterized surface plasmon waveguides for near infrared light in the telecommunications spectrum. These waveguides exhibit losses of -1.2dB/μm and can guide light around 0.5 μm bends. Light can also be efficiently coupled between more conventional silicon waveguides and these plasmon waveguides with compact couplers, and we demonstrate that surface plasmon optical devices can be constructed by using planar circuit fabrication techniques. The large optical field enhancements of metallic surface plasmon devices are expected to lead to a new class of plasmonic optical devices, which will take advantage of the large field enhancements at the surfaces of the plasmon waveguides for nonlinear or sensing functionality, while utilizing the low losses available in silicon waveguides to move light longer distances on chip

The spinning artificial gravity environment: A design project

The SAGE, or Spinning Artificial Gravity Environment, design was carried out to develop an artificial gravity space station which could be used as a platform for the performance of medical research to determine the benefits of various, fractional gravity levels for astronauts normally subject to zero gravity. Desirable both for its medical research mission and a mission for the study of closed loop life-support and other factors in prolonged space flight, SAGE was designed as a low Earth orbiting, solar powered, manned space station

A Longitudinal Perspective Regarding the Use of VLEs by Higher Education Institutions in the United Kingdom

The version uploaded is the final copy that was sent to the publishers.Between 2001 and 2005 UCISA and JISC conducted surveys into issues relating to the acquisition, use, management and support of Virtual Learning Environments (VLEs). A number of other studies provide information on these issues during this period. Together they provide a substantial body of evidence that allows an analysis of the factors that enhance or inhibit institutional take-up and support provision for VLEs within the UK higher education sector. There is clear evidence of increasing use of VLEs but not of widespread change in pedagogic practice. VLE management is increasingly centralised in all matters considered strategic, with dedicated devolvement occurring for a range of support activities. Differences in practice exist between old and new universities. There is in general negligible interest in standards or in institutional collaboration

Effective strategies to strengthen the mental health and wellbeing of Aboriginal and Torres Strait Islander people

Introduction: The purpose of this paper is to draw on Aboriginal and Torres Strait Islander (Indigenous) perspectives, theoretical understandings, and available evidence to answer questions about what is required to effectively address Indigenous people’s mental health and social and emotional wellbeing. Social and emotional wellbeing is a multifaceted concept. Although the term is often used to describe issues of ‘mental health’ and ‘mental illness’, it has a broader scope in that Indigenous culture takes a holistic view of health. It recognises the importance of connection to land, culture, spirituality, ancestry, family and community, how these connections have been shaped across generations, and the processes by which they affect individual wellbeing. It is a whole-of-life view, and it includes the interdependent relationships between families, communities, land, sea and spirit and the cyclical concept of life–death–life. Importantly, these concepts and understandings of maintaining and restoring health and social and emotional wellbeing differ markedly to those in many non-Indigenous-specific (or mainstream) programs that tend to emphasise an individual’s behavioural and emotional strengths and ability to adapt and cope with the challenges of life. This paper explores the central question of ‘what are culturally appropriate mental health and social and emotional wellbeing programs and services for Indigenous people, and how are these best delivered?’. It identifies Indigenous perspectives of what is required for service provision and program delivery that align with Indigenous beliefs, values, needs and priorities. It explores the evidence and consensus around the principles of best practice in Indigenous mental health programs and services. It discusses these principles of best practice with examples of programs and research that show how these values and perspectives can be achieved in program design and delivery. This paper seeks to provide an evidence-based, theoretically coherent discussion of the factors that influence the effective development, implementation and outcomes of initiatives to address Indigenous mental health and wellbeing issues. It seeks to assess whether the current investment in Indigenous people’s mental health is aligned with available evidence on what works. To this end, the paper reviews Australian literature and government health, mental health and social and emotional wellbeing policies and programs. The scope of programs and their criteria for inclusion in this paper are informed by the Key Result Area 4, Social and Emotional Wellbeing objectives, within the National Strategic Framework for Aboriginal and Torres Strait Islander Health 2003–13: Australian Government Implementation Plan 2007–2013. This paper acknowledges the holistic nature of health, mental health and wellbeing, and the effects of Australia’s colonial history and legacy on the contemporary state of Indigenous social and emotional wellbeing. It recognises that there is a complex relationship between social and emotional wellbeing, harmful substance misuse, suicide, and a range of social and economic factors. Although this paper encompasses the broad priorities identified within the key Indigenous mental health policies and frameworks, it does not provide a detailed discussion of programs and resources that, although relevant here, are covered in a number of existing Closing the Gap Clearinghouse resource sheets and issues papers (see Appendix 1). These interweavings and overlaps are not surprising given the complexity and interconnectedness of the issues and determinants that are being addressed to strengthen Indigenous mental health and wellbeing

Segmented waveguides in thin silicon-on-insulator

We have developed new silicon-on-insulator waveguide designs for simultaneously achieving both low-loss optical confinement and electrical contacts, and we present a design methodology based on calculating the Bloch modes of such segmented waveguides. With this formalism, waveguides are designed in a single thin layer of silicon-on-insulator to achieve both optical confinement and minimal insertion loss. Waveguides were also fabricated and tested, and the measured data were found to closely agree with theoretical predictions, demonstrating input insertion loss and propagation loss better than 0.1 dB and -16 dB/cm, respectively