Combined computer-generated hologram for testing steep aspheric surfaces.
A novel type of a combined (or multiplex) computer-generated hologram (CGH) and a method for interferometric testing of steep axially symmetric aspheres is presented. The method is based on a hybrid CGH containing two different diffractive structures. The presented new type of Diffractive Fizeau Null Lens (DFNL) design eliminates the transmitted wavefront distortion (TWD) of the CGH substrate and increases the accuracy of the surface test. The method was approved by testing a spherical reference mirror with an f-number of f/0.65.
Poleshchuk
A G
AG
Institute of Automation and Electrometry, Russian Academy of Science, Russia.
Nasyrov
R K
RK
Asfour
J-M
JM