Dynamic interferometry, one of several technologies pioneered and patented by 4D Technology, enables complex testing without vibration isolation, even in the noisiest environments.
With Dynamic Interferometry you can measure between multiple tables, in environmental chambers, over long paths or in noisy cleanrooms.
In a conventional phase-shifting laser interferometer, multiple frames of data are acquired over many milliseconds—enough time for vibration and turbulence to degrade the measurement results.
In Dynamic Interferometry polarization is used to encode the test and reference beam. A proprietary, high speed, high resolution wavefront sensor enables all measurement data to be acquired simultaneously, in as little as 30 microseconds. Such high speed enables 4D laser interferometers to measure the shape of optical surfaces with extreme accuracy—despite vibration and environmental noise.
Odd shapes, pupil obscurations, poor signal contrast, moving parts, air turbulence and mechanical vibration are not problems for Dynamic Interferometry. Special wavefront sensors have also been developed for wavelength insensitivity, higher spatial resolution, and applications within tight space restrictions.