title: Exploration of the optimisation algorithms used in the implementation of adaptive optics in confocal and multiphoton microscopy.
abstract: We report on the introduction of active optical elements into confocal and multiphoton microscopes in order to reduce the sample-induced aberration. Using a flexible membrane mirror as the active element, the beam entering the rear of the microscope objective is altered to produce the smallest point spread function once it is brought to a focus inside the sample. The conventional approach to adaptive optics, commonly used in astronomy, is to utilise a wavefront sensor to determine the required mirror shape. We have developed a technique that uses optimisation algorithms to improve the returned signal without the use of a wavefront sensor. We have investigated a number of possible optimisation methods, covering hill climbing, genetic algorithms, and more random search methods. The system has demonstrated a significant enhancement in the axial resolution of a confocal microscope when imaging at depth within a sample. We discuss the trade-offs of the various approaches adopted, comparing speed with resolution enhancement.
authors: Institute of Photonics, Wolfson Centre, Glasgow G4 0NW, United Kingdom. a.wright@strath.ac.uk
authors: Amanda J
authors: AJ
authors: Wright
authors: David
authors: D
authors: Burns
authors: Brett A
authors: BA
authors: Patterson
authors: Simon P
authors: SP
authors: Poland
authors: Gareth J
authors: GJ
authors: Valentine
authors: John M
authors: JM
authors: Girkin
mesh_terms: D000465:Algorithms; D005583:Fourier Analysis; D007091:Image Processing, Computer-Assisted; D018613:Microscopy, Confocal / Q000295:instrumentation; D036641:Microscopy, Fluorescence, Multiphoton / Q000295:instrumentation; D055095:Optics and Photonics