Biomedical subjects

MA Neil

Publications and source records attributed to MA Neil.

4 recordsLinked to original sources

PubMed2000

A wavefront generator for complex pupil function synthesis and point spread function engineering.

We describe a simple method to produce an arbitrary complex optical field using a ferroelectric liquid crystal spatial light modulator. The system is configured so as to act as a pupil plane filter in a confocal microscope. The ability to tune the complex pupil function permits the system to be used both to modify the imaging performance by effectively engineering the point spread function as well as to remove optical aberrations present in the optical system.

Journal Article↗

PubMed2000

Adaptive aberration correction in a two-photon microscope

We demonstrate aberration correction in two-photon microscopy. Specimen-induced aberrations were measured with a modal wavefront sensor, implemented using a ferro-electric liquid crystal spatial light modulator (FLCSLM). Wavefront correction was performed using the same FLCSLM. Axial scanned (xz) images of fluorescently labelled polystyrene beads using an oil immersion lens show restored sectioning ability at a depth of 28 &mgr;m in an aqueous specimen.

Journal Article↗

PubMed2000

New modal wave-front sensor: a theoretical analysis

We present a new design of a modal wave-front sensor capable of measuring directly the Zernike components of an aberrated wave front. The sensor shows good linearity for small aberration amplitudes and is particularly suitable for integration in a closed-loop adaptive system. We introduce a sensitivity matrix and show that it is sparse, and we derive conditions specifying which elements are necessarily zero. The sensor may be temporally or spatially multiplexed, the former using a reconfigurable optical element, the latter using a numerically optimized binary optical element. Different optimization schemes are discussed, and their performance is compared.

Journal Article↗

PubMed1998

Real-time three-dimensional imaging of macroscopic structures.

We describe an extremely simple method of obtaining optically sectioned images with conventional low-power imaging systems in real time. A single spatial frequency grid pattern is projected onto an object. Images taken at three spatial positions of the grid projection are processed to provide 3D images of macroscopic structures.

Journal Article↗