Andorra Optics has had many years of optical testing experience in a production environment. This applies to conventional optical fabrication as well as diamond turning of aspheric surfaces. The testing of diamond-turned aspheric surfaces requires designing and aligning null lenses (or null mirrors).
These null optics and the associated layout must be designed and toleranced in the same fashion as an optical system with procedures for setting up, aligning the system, and generating interferograms for evaluation.
For example, we have had experience with system testing on three-mirror anastigmats and other multi-mirror systems using interferometric results as feedback for improving the performance. In this setup, the interferogram was input to the original design at the exit pupil and a suitable parameter or set of parameters (such as surface tilt/decenter) was varied to cancel or minimize the errors allowing, in these cases, for the system to meet the specifications.
We offer expertise in the design and layout of optical test apparatus for testing surfaces, sub-assemblies, or complete systems. In addition, guidance in interpreting interferograms or other test results is offered.