Exploration of the optimisation algorithms used in the implementation of adaptive optics in confocal and multiphoton microscopy

✍ Scribed by Amanda J. Wright; David Burns; Brett A. Patterson; Simon P. Poland; Gareth J. Valentine; John M. Girkin

• Publisher: John Wiley and Sons
• Year: 2005
• Tongue: English
• Weight: 640 KB
• Volume: 67
• Category: Article
• ISSN: 1059-910X
• DOI: 10.1002/jemt.20178

✦ Synopsis

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.