UCL Discovery
UCL home » Library Services » Electronic resources » UCL Discovery

Acousto-optic Lens Control: a frequency synthesiser for random access microscopy and wavefront engineering

Konstantinou, G; (2014) Acousto-optic Lens Control: a frequency synthesiser for random access microscopy and wavefront engineering. Doctoral thesis , UCL (University College London).

Full text not available from this repository.

Abstract

Two-photon microscopy has become an invaluable tool for imaging neural activity at the cellular level. The non-linear excitation process of two-photon imaging has enabled neuroscientists to observe multiple brain cell dynamics at a higher depth, while causing lower photo-damage in comparison to confocal microscopy. However, conventional galvanometer-mirror based two-photon microscopes are not agile enough to follow the action-potential path between firing neurons. A fast scanning and refocusing 3D two-photon microscope has been developed by the Department of Neuroscience, Physiology and Pharmacology of University College London capable of rapid accessing hundreds of points of interest. The instrument achieves this by employing a new type of 3D scanner that uses four Acousto-Optic Deflectors (AODs) to form a high performance Acousto-Optic Lens. The aim of this research is to develop a highly sophisticated system capable of generating the necessary signals to drive the four AODs. Such a system would enable arbitrary 3D scanning and compensate for inherent aberration of the op-tical systems as well as tissue-induced aberrations, and revolutionise neural ac-tivity imaging. Different paths to developing the control system and synthesiser were investi-gated in depth and evaluated, in order to yield a confident selection of tools, technologies, platforms and techniques. Since the early research stages, it was realised that the system should be developed around a Field Programmable Gate Array (FPGA) device, a new technology but ideal for fast parallel systems. The resulted system is capable of generating amplitude modulated, non-linear frequency ramps at a very high precision. Using several experimental setups, it was shown that with this driver the AOL is not only capable of rapid access 3D focusing, but also rapid scanning and correcting for aberrations, making it a via-ble adaptive optics device. A fast scanning, rapidly focusing lens, which can compensate for specimen and/or optical path aberrations, can revolutionise functional imaging and open new horizons in the exploration and understanding of the human brain.

Type: Thesis (Doctoral)
Title: Acousto-optic Lens Control: a frequency synthesiser for random access microscopy and wavefront engineering
Language: English
Additional information: Permission for digitisation not received.
UCL classification: UCL
UCL > Provost and Vice Provost Offices > School of Life and Medical Sciences
UCL > Provost and Vice Provost Offices > School of Life and Medical Sciences > Faculty of Life Sciences
UCL > Provost and Vice Provost Offices > UCL BEAMS
UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Engineering Science
UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Engineering Science > Dept of Electronic and Electrical Eng
URI: https://discovery.ucl.ac.uk/id/eprint/1419717
Downloads since deposit
2Downloads
Download activity - last month
Download activity - last 12 months
Downloads by country - last 12 months

Archive Staff Only

View Item View Item