The range of local wavefront curvatures measurable with Shack-Hartmann wavefront sensors.

Shack-Hartmann wavefront sensor systems are studied to assess the range of local wavefront curvatures that may be measured for a given choice of lenslet size and focal length and illumination beam characteristics, with special emphasis on systems design for use in wavefront eye refractors. Effects considered include blur effects on detected spot size,spot differential movement due to local wavefront curvature and source size effects.Examples are given, using a full diffractive treatment of the spot intensity patterns, to illustrate that the maximum range values found using the method of this paper result in neighbouring spot intensity patterns that are at the limit for resolution.