We discuss error propagation in the slope-based and the difference-based wavefront estimations. The error propagation coefficient can be expressed as a function of the eigenvalues of the wavefront-estimation-related matrices, and we establish such functions for each of the basic geometries with the serial numbering scheme with which a square sampling grid array is sequentially indexed row by ro...

Rats rhythmically sweep their whiskers over object features, generating sequential deflections of whisker arcs. Such moving wavefronts of whisker deflection are likely to be fundamental elements of natural somatosensory input. To determine how moving wavefronts are represented in somatosensory cortex (S1), we measured single- and multiunit neural responses in S1 of anesthetized rats to moving w...

Wavefront sensors, which use solid-state CCD or CMOS photosensors, are sources of errors in adaptive optic systems. Inaccuracy in the detection of wavefront distortions introduces considerable errors into wavefront reconstruction and leads to overall performance degradation of the adaptive optics system. The accuracy of wavefront sensors is significantly affected by photosensor noise. Thus, it ...

We report on an integrated Hartmann wavefront sensor (WFS) using passive-pixel architecture and pixels clustered as position-sensitive detectors for dynamic wavefront analysis. Such a device detects the degrees of imperfection (aberrations) of a light beam by measuring the deviation of the incoming wavefront from a reference one. It can be employed either as a diagnostic tool, or in close loop ...

In this paper, transfinite element method is used to analyze the two dimensional thermoelasticity problems. A comparison is made between the thermoelastic analysis results of the classical theory and theories with one or two relaxation times (i.e. L-S and G-L theories), for the half space problem. Governing equations are transformed to Laplace domain and then, node variables are calculated by t...

One of the solutions of the Helmholtz equation is the vortex beams. In the recent decades, production and applications of these types of beams have found serious attentions. Determination of the vortex beam topological charge and its sign are very important issues. Odd number of reflections of the vortex beam changes its vorticity. In this paper, we have used a q-plate to generate a vortex beam...

The concept of a differential Shack-Hartmann (DSH) curvature sensor was recently proposed, which yields wavefront curvatures by measuring wavefront slope differentials. As an important feature of the DSH curvature sensor, the wavefront twist curvature terms can be efficiently obtained from slope differential measurements, thus providing a means to measure the Monge-equivalent patch. Specificall...

We propose a wavefront measurement method based on Talbot effect. It is well known that the wavefront of large aperture long focal lens is difficult to be measured. Here a new method for wavefront measurement of large aperture long focal lens is presented, which is accomplished by fitting the slope of sub-wavefront in the whole aperture while the sub-wavefront slope is got by calculating the sh...

Wavefront sensor noise and fidelity place a fundamental limit on achievable image quality in current adaptive optics ophthalmoscopes. Additionally, the wavefront sensor 'beacon' can interfere with visual experiments. We demonstrate real-time (25 Hz), wavefront sensorless adaptive optics imaging in the living human eye with image quality rivaling that of wavefront sensor based control in the sam...

We validate the quantitative analysis of Ronchigrams for wavefront sensing through detailed numerical simulations. Analysis of the experimental Ronchigrams provides the wavefront aberrations, the F/# of the beam and the distance of the Ronchi ruling from the paraxial focus. These retrieved parameters are used to numerically simulate the Ronchigrams with excellent agreement. This favorable compa...