AOLI: Adaptive Optics plus Lucky Imager for the WHT (4.2m) and GTC (10.5m) Telescopes.

The highest resolution images of faint targets ever taken in the visible or near infrared were obtained by combining Lucky Imaging with low order adaptive optics. This proposal is to develop further the technologies needed for an innovative approach to wavefront sensing that will allow dramatically fainter reference stars to be used than with conventional Shack-Hartmann sensors. These will be incorporated in an instrument to be used initially on the WHT 4.2 m with the potential to move to the GTC 10 meter telescope on La Palma. Using only faint natural guide stars, angular resolution as good as 15 milliarcseconds in the GTC and 40 milliarcseconds on the WHT in I-band will be obtained over a substantial fraction of the northern sky. The instrument is part of a collaboration led by the Institute of Astronomy of the University of Cambridge, with the IAC (La Laguna), UPCT (Cartagena), University of Cologne and the staff of the ING (La Palma).
This project is central to the aims and aspirations of the STFC science program for astronomy. It also supports the strongly expressed wish to integrate activities of the ING with those of the IAC/GranteCan telescope on La Palma. The project builds on several exciting new technologies that have made great strides over the last year in Cambridge. In particular, much higher selection percentages are now achieved without loss of resolution. The instrument proposed here will start as a visitor instrument permanently resident on the island, with the medium-term goal of transitioning to a common user facility for use on the two La Palma telescopes. The instrument first light on the WHT will be ~18 months after kick-off and fully operational by the end of 3 years. The costs will be shared between the UK and collaborators in Spain and Germany. This proposal is for a total of £138K from STFC (£167K FEC) including components, travel and salaries. The entire project is expected to cost in the region of £1.5 million.

We are already collaborating with researchers in the application of Lucky Imaging for ground-based surveillance under an initiative for Crime Prevention and Detection (Qinetiq and Selex) and also with a group developing high-resolution technologies for ophthalmic imaging using lucky imaging techniques to dramatically improve the capability of instruments to detect and track the development of diseases such as age-related macular degeneration and diabetic retinopathy with the University of London. in addition, we are collaborating with the University of Cambridge Department of Oncology to improve the targeting of radiation therapy on difficult to treat tumours. Our interest in exploiting these technologies outside the astronomy/physics community will be further enhanced by the developments proposed for the AOLI instrument.

The surveillance work uses many of the technologies already developed for astronomy applications for taking pictures across terrestrial lines of sight. It is surprising that we are limited to a range of about 200 m for be able to identify human face. Long-distance surveillance methods only allow very low fidelity imaging. We have been developing variations on the lucky imaging theme where the anisoplanatism that is a major problem for ground-based surveillance is managed by breaking the image into multiple cells and assembling lucky images over many separate small parts of the field which are ultimately recombined to give high resolution images. We have been able to obtain an improvement of a factor of 8-12 in resolution, very similar to the resolution that we have already demonstrated for conventional lucky imaging in astronomy.

More recently we have started a program of work with the University of London who already have a considerable amount of experience in high-resolution ophthalmic imaging. We are working with them to use the lucky imaging techniques behind a high magnification ophthalmoscope. The ability to image individual cells in the retina is very important for two main diseases which are presently exploding in importance in the UK and indeed across the world. Age-related macular degeneration (AMD) is simply the death of retinal cells in the centre of the field of view that causes progressive degeneration in the vision, often on timescales of just a few weeks. The ability to image individual cells and determine the extent of cell death is critical not simply for diagnosing the disease but helping to track its development and response to medication. In diabetic retinopathy it is important to be able to detect the incidence of micro-aneurysms, small amount of blood leaking out of the vessels in the retina. They can block part of the retina causing progressive blindness, a major consequence of diabetes. Again the ability to track the degree of control provided by medication is critical to minimising this devastating side-effect.

We are also working with the Addenbrooke's Hospital/University of Cambridge Department of Oncology and a US manufacturer of tomographic radiotherapy equipment to improve the spatial resolution obtained with energetic computed tomography scans prior to radiation therapy treatment of cancer patients. The techniques developed for lucky imaging that reduce the distortion caused by atmospheric turbulence can be applied directly to the combination of the multiple scans usually taken as part of radiotherapy treatment. This has the potential to improve greatly the targeting of radiation therapy to maximise its impact on the tumour while minimising the collateral damage on sensitive tissues near the tumour site.

A research group in the University of Oxford (chemistry and pathology departments) are now using Lucky Imaging techniques are now being used to enhance substantially the high-resolution optical imaging of fluorescent dye molecules, quantum dots and the in vivo imaging of fluorescently labelled linker for activation of T cells.