Open AccessMEMS segmented-based adaptive optics scanning laser ophthalmoscope
Author(s) -
Silvestre Manzanera,
Michael A. Helmbrecht,
Carl J. Kempf,
Austin Roorda
Publication year - 2011
Publication title -
biomedical optics express
Language(s) - Uncategorized
Resource type - Journals
SCImago Journal Rank - 1.362
H-Index - 86
ISSN - 2156-7085
DOI - 10.1364/boe.2.001204
Subject(s) - deformable mirror , optics , adaptive optics , tilt (camera) , wavefront , wavefront sensor , piston (optics) , scanning laser ophthalmoscopy , physics , microelectromechanical systems , laser , aperture (computer memory) , optoelectronics , mechanical engineering , engineering , acoustics
The performance of a MEMS (micro-electro-mechanical-system) segmented deformable mirror was evaluated in an adaptive optics (AO) scanning laser ophthalmoscope. The tested AO mirror (Iris AO, Inc, Berkeley, CA) is composed of 37 hexagonal segments that allow piston/tip/tilt motion up to 5 μm stroke and ±5 mrad angle over a 3.5 mm optical aperture. The control system that implements the closed-loop operation employs a 1:1 matched 37-lenslet Shack-Hartmann wavefront sensor whose measurements are used to apply modal corrections to the deformable mirror. After a preliminary evaluation of the AO mirror optical performance, retinal images from 4 normal subjects over a 0.9°x0.9° field size were acquired through a 6.4 mm ocular pupil, showing resolved retinal features at the cellular level. Cone photoreceptors were observed as close as 0.25 degrees from the foveal center. In general, the quality of these images is comparable to that obtained using deformable mirrors based on different technologies.