Measuring Large Optics Easily
A meter-class spherical poses substantial problems for accurate shape measurements. Large cavities, turbulence control, vibration isolation, microadjustment for alignment and low reflectivity can all create headaches.
In this short video, applications engineer Jared Wheeler demonstrates how easy it is to align a large optic if you only need to adjust the position of a small, light interferometer.
Taking high precision measurements (suitable for lambda/20 optical quality) in a situation where the optic and interferometer are not vibrationally linked, the air cavity is large and turbulent, you see how fast it is to get clean, precise averaged measurements by using dynamic metrology and an optical system that preserves much of the light from the interferometer.
In an extended demonstration, Jared shows how the instrument can measure low reflectivities or high, with a simple adjustment in the software.