Method of wavefront sensing by mapping boundaries of a lenslet array onto a grid of pixels
View Patent ↗A system and method of wavefront sensing with a Shack-Hartmann wavefront sensor precisely locates focal spots on a detector array, and determines the location of the lenslet array with respect to the detector array.
1. A method of reconstructing a wavefront from gradient data, comprising:
obtaining gradient data from a Shack-Hartmann wavefront sensor comprising a lenslet array and a plurality of pixels;
mapping boundaries of each lenslet onto a grid of the pixels; and
numerically calculating the wavefront at a plurality of vertices of said mapped boundaries.
2. The method of claim 1 , wherein the wavefront is calculated by minimizing differences between adjacent lenslet vertices.
3. The method of claim 2 , where the wavefront is calculated using a least squares fit method.
4. The method of claim 3 , wherein performing the least squares fit method comprises:
obtaining a design matrix that is only a function of the basis functions and coordinate space; and
performing a matrix multiplication of the design matrix and an array composed of the gradient data.
5. The method of claim 4 , where the design matrix is stored in a storage medium.
6. The method of claim 1 where the wavefront is calculated by one of: a successive over-relaxation method, a gradient search method, a singular value decomposition, and a neural net method.
7. The method of claim 1 where an existence function is used to determine valid measurement locations for obtaining the gradient data.
8. The method of claim 7 where the existence function is determined from a measured irradiance distribution.