HartmannWfsDft

HartmannWfsDft models a Hartmann-Shack wavefront sensor. For any incident wavefront, the complex field over each subaperture is propagated to the sensor plane (usually at the common focal plane of the subaperture lenslets) using a DFT, then the fields from all the subapertures are superposed and the net intensity is computed. Finally, the net intensity is integrated over the exposure length to produce an "integratedIntensity" output in units of J/m^2.

In addition to integratedIntensity in the sensor plane, HartmannWfsDft also computes subaperture centroids to yield noise-free, high-resolution subapertures slopes. See the LightLike User Guide for discussion of these slopes compared to noisy slopes obtained by appending further subsystems to HartmannWfsDft.

HartmannWfsDft can model any number of subapertures, in any geometry. Subaperture geometries are generally created using the LightLike suite's AOGeom GUI. That GUI can create a data file whose relevant subaperture specifications can be easily read into the {xSubap, ySubap} parameters of HartmannWfsDft.

The temporal triggering and exposure parameters of HartmannWfsDft are identical to those of those of the more basic LightLike sensors. See the LightLike User Guide for a detailed discussion of the triggering of sensor exposures. Note in particular that the input "sampleInterval" is only used to generate multiple samples within one "exposureLength". To obtain one sample per "exposureLength" (the typical practice), set "sampleInterval" to 0.0.

HartmannWfsDft also allows an optional delay used to model readout time: if this is set non-zero, then the output only becomes available at that delay after the end of the exposure length window.

Like all LightLike optical sensors, HartmannWfsDft works with both pulsed and continuous wave illumination. If multiple wavefronts (i.e., from separate sources) are received simultaneously they are assumed to be mutually incoherent, so their intensities add.

HartmannWfsDft is a complex module: the LightLike User Guide gives further guidance on its usage and the setting of parameters.

Note that two of the parameters are annotated as "Used ONLY with Wavesharing". For essentially all LightLike usage, these parameters have NO effect whatsoever: leave the values at their defaults (for advanced usage, see LightLike User Guide for details).