Calibration of deformable mirrors using phase diversity
PROGRAM DOWNLOAD
Click here to download the phase retrieval software
The program was developed using LabView 8.6 and requires that the LabView runtime 7.1.1 be installed on your computer. Instructions for use are included.
In adaptive optics the precise control of the wavefront modulation induced by the active element (deformable mirror or SLM) used for correction is an essential step towards fast and accurate correction.We have developed a method to extract the amplitude and phase of the electric field at the entrance pupil of a microscope objective from 3 PSF images.
Example of electric field reconstruction: (a)-(c), 2D PSF images for a 20x, 0.75NA air objective. Scale bar, 10µm; (d), reconstructed amplitude (a.u.); (e), (f), reconstructed phase before (e) and after (f) imaging.
By measuring the variations of this electric field as a function of the commands send to a deformable mirror, its influence function in the entrance pupil can be calibrated for subsequent use for wavefront control.
Phase influence function of an actuator of a deformable mirror calibrated using phase diversity (left) and a Shack-Hartmann wavefront sensor (center). Right, difference between the two measured profiles downsampled to the same resolution.
Details about the experimental setup and the retrieval algorithm can be found in the reference:
"Simple characterisation of a deformable mirror inside a high numerical aperture microscope using phase diversity"
D. Débarre, T. Vieille and E. Beaurepaire
J. Microsc. 244(2), 136-143 (2011). doi: 10.1111/j.1365-2818.2011.03518.x PDF