The advent of negative index materials has spawned extensive research into metamaterials over the past decade. Metamaterials are attractive not only for their exotic electromagnetic properties, but also their promise for applications. A particular branch–the metamaterial perfect absorber (MPA)–has garnered interest due to the fact that it can achieve unity absorptivity of electromagnetic waves. Since its first experimental demonstration in 2008, the MPA has progressed significantly with designs shown across the electromagnetic spectrum, from microwave to optical. In this Progress Report we give an overview of the field and discuss a selection of examples and related applications. The ability of the MPA to exhibit extreme performance flexibility will be discussed and the theory underlying their operation and limitations will be established. Insight is given into what we can expect from this rapidly expanding field and future challenges will be addressed.

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We present a single pixel terahertz (THz) imaging technique using optical photoexcitation of semiconductors to dynamically and spatially control the electromagnetic properties of a semiconductor mask to collectively form a THz spatial light modulator (SLM). By co-propagating a THz and collimated optical laser beam through a high-resistivity silicon wafer, we are able to modify the THz transmission in real-time. By further encoding a spatial pattern on the optical beam with a digital micro-mirror device (DMD), we may write masks for THz radiation. We use masks of varying complexities ranging from 63 to 1023 pixels and are able to acquire images at speeds up to 1/2 Hz. Our results demonstrate the viability of obtaining real-time and high-fidelity THz images using an optically controlled SLM with a single pixel detector.

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Introduction: Young-onset dementia affects about 1 in 1500 people aged under 65 years in the United Kingdom (UK). It is associated with loss of employment, independence and an increase in psychological distress. This project set out to identify the benefits of a 2 hours per week structured activity programme of gardening for people with young-onset dementia. Method: A mixed methods (qualitative and quantitative) study of therapeutic gardening for people with young-onset dementia, measuring outcomes for both participants with young-onset dementia and their carers, was used. Twelve participants were recruited from a county-wide mental health service for older adults, based on onset of dementia being before the age of 65 years (range 43–65 years). Of these, two participants dropped out and one died during the project. Measures included the Mini Mental State Examination (MMSE), Bradford Well-Being Profile, Large Allen Cognitive Level Screen (LACLS) and Pool Activity Level (PAL). Findings: Over a 1-year period the carers of the people with young-onset dementia found that the project had given participants a renewed sense of purpose and increased well-being, despite cognitive functioning continuing to decline during this period. Conclusion: This study suggests that a meaningful guided activity programme can maintain or improve well-being in the presence of cognitive deterioration.