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We describe a method for tracking the position of small features in three dimensions from images recorded on a standard microscope with an inexpensive attachment between the microscope and the camera. The depth-measurement accuracy of this method is tested experimentally on a wide-field, inverted microscope and is shown to give approximately 8 nm depth resolution, over a specimen depth of approximately 6 µm, when using a 12-bit charge-coupled device (CCD) camera and very bright but unresolved particles. To assess low-flux limitations a theoretical model is used to derive an analytical expression for the minimum variance bound. The approximations used in the analytical treatment are tested using numerical simulations. It is concluded that approximately 14 nm depth resolution is achievable with flux levels available when tracking fluorescent sources in three dimensions in live-cell biology and that the method is suitable for three-dimensional photo-activated localization microscopy resolution. Sub-nanometre resolution could be achieved with photon-counting techniques at high flux levels.

International audience; The CANARY on-sky MOAO demonstrator is being integrated in the laboratory and a status update about its various components is presented here. We also discuss the alignment and calibration procedures used to improve system performance and overall stability. CANARY will be commissioned at the William Herschel Telescope at the end of September 2010.

International audience; EAGLE is a multi-object 3D spectroscopy instrument currently under design for the 42-metre European Extremely Large Telescope (E-ELT). EAGLE will use open-loop Multi-Object Adaptive Optics (MOAO) to provide partial AO correction across a wide (5-10 arcmin) field of view. The novelty of this scheme is such that on-sky demonstration is required prior to final construction of an E-ELT instrument. The CANARY project will implement a single channel of an MOAO system on the 4.2m William Herschel Telescope. The CANARY project is undergoing a phased development plan that starts with demonstration of low-order open-loop AO correction using first NGS then Rayleigh LGS tomography, moving to a demonstration of high-order open-loop AO correction using LGS tomography. This final stage will also include 2 DMs in a woofer-tweeter configuration similar to that of EAGLE when installed at the E-ELT. We describe the requirements for the various phases of MOAO demonstration, the corresponding CANARY configurations and capabilities and the current designs of the various subsystems.

A conventional microscope produces a sharp image from just a single object-plane. This is often a limitation, notably in cell biology. We present a microscope attachment which records sharp images from several object-planes simultaneously. The key concept is to introduce a distorted diffraction grating into the optical system, establishing an order-dependent focussing power in order to generate several images, each arising from a different object-plane. We exploit this multiplane imaging not just for bio-imaging but also for nano-particle tracking, achieving approximately 10 nm z position resolution by parameterising the images with an image sharpness metric.