Speckle reduction in ocular wave-front sensing

TL;DR

This paper presents a method using an acousto-optic cell to reduce speckle noise in ocular wave-front sensing, improving measurement accuracy of eye aberrations by spreading the laser beam to average out speckles.

Contribution

The study introduces a novel speckle reduction technique employing acousto-optic diffraction to enhance wave-front sensor performance in ophthalmic applications.

Findings

Speckle noise was effectively reduced using the acousto-optic method.

The method improved the uniformity of wave-front measurements.

Enhanced accuracy in ocular aberration assessment was demonstrated.

Abstract

An acousto-optic cell was used to reduce the speckle noise that reduces the quality of Hartmann-Shack and other wave-front sensors measuring ocular aberrations. In the method presented here, a laser beam traverses an acousto-optic cell, interacting with standing acoustic waves. Speckle reduction takes place as the incoming beam is diffractively spread across the cornea. The increased size and the wider angular spread of the incoming beam average out the speckles, producing a more uniform response of the wave-front sensor.