Experiment Wave Surface Analyzer - Shack Hartmann

Subjects discussed :
- Optical metrology, alignment and autocollimation
- Calibration, study of quality criteria for optical components (doublet, lens)
- Wave surface analysis, measurement of geometric and chromatic aberrations
- Image spot (Point Spread Function = PSF), Modulation Transfer function (FTM), Strehl ratio
- Zernike polynomials
- Reconstruction of the wave surface using zonal and/or modal methods

Principles and objectives:
The assembly uses a sensor called ASO (Wave Surface Analyzer) which is an array of 38x38 microlenses coupled to a CMOS matrix (2592x1944 pixels). Each lens converges the wave into a spot whose position depends on the local slope that the wave had on the lens in question (see previous diagram). By comparing the positions of the spots in relation to the reference points, the software is able to reproduce the shape of the wavefront.
This software, supplied with the wavefront analyzer, allows you to visualize, record and reconstruct the wave surface in real time. It can also quantify optical aberrations, calculate Zernike polynomials, analyze MTF or PSF.
The main goal of this practical work is to determine the quality of an optical system (for example a doublet, in infinite-focus configuration) using a Shack-Hartmann type ASO. In addition, the user will be trained in optical adjustments and alignments, system calibration and data exploitation.

This product was developed in collaboration with the Institut d’Optique Graduate School of St Etienne.

The ASO was specially designed and developed by a specialist in astronomy imaging and instrumentation.
The Software allows you to view and save the ASO image and perform wave surface reconstruction using zonal and/or modal methods. It makes it possible, among other things, to calibrate the system, to provide the Zernike coefficients and to quantify the associated aberrations or to go back to the profile of the wave surface.

Composition :
▪ 1 optical honeycomb table 600x450 mm (ref.203268)
▪ 4 magnetic feet (ref.202542)
▪ 1 magnetic foot with lateral translation (ref.202707)
▪ 1 illumination kit: LED source with pinhole (10 and 50 μm), power supply and support
▪ 1 non-polarizing 50-50 separator cube, L=25 mm (ref.203378)
▪ 1 prism holder plate with holding finger (ref.205132)
▪ 1 mirror diameter 40mm (lambda/20 flatness) in frame with X-Y adjustment (ref.205133)
▪ 1 achromatic doublet diameter 50.8mm, F=+300mm
▪ 1 plano-convex lens diameter 50.8 mm, F=+300mm with barrel
▪ 1 mount for component diameter 50.8 mm (ref.204890)
▪ 1 optical coupling nut (ref.205048)
▪ 1 ASO Shack Hartmann 38x38 points
▪ 1 acquisition and processing software
▪ 1 experiment note