This video shows several types of micro-lenses that I made using a DIY maskless wafer stepper. The tiny lenses can for example be used for building a Shack-Hartmann wavefront detector.

Explanation of the Shack-Hartmann principle can be found on Wikipedia:
https://en.wikipedia.org/wiki/Shack%E...

This is the download link for Windows installer for the Zone Plate app:

http://www.huygensoptics.com/assets/z...

YouTube does not like to redirect to this link. the file is (last part of the URL): /assets/zp_writer.zip

For Windows 10 and for personal use only. Virus scanners and Windows will nag about it being a rare / unknown file and make installation sometimes difficult. Sorry about that. Install this app at your own risk.

Link to the maskless wafer stepper playlist:
   • DIY Maskless Wafer Stepper  

Applied science video on photolithography:
   • Antique 4x5 camera creates 20 micron ...  

Reference for article on zone plate design:
https://laser.physics.sunysb.edu/_pra...
Wikipedia also explains this very clearly, but I just found this article first.

Links to some commercially available Shack-Hartmann detectors:
https://www.thorlabs.com/newgrouppage...
https://www.optocraft.de/products-shs...

@ 0.34m: four happy seconds with Deodato, listen to the full song at:
   • Deodato - Happy hour (1982) vinyl