Satellite-based observatories and optics program rely on 4D to ensure successful performance in the challenging conditions of space. The current designs for space-based optics include more aspheric elements for weight and size reduction, segmented optics that can be folded into spacecraft, and a variety of exotic materials that must be tested at the functional wavelength. Many mission-critical optical systems are also tested at cryogenic conditions inside environmental chambers to verify their post-launch characteristics.
4D PhaseCam Twyman-Green interferometers measure small and large concave elements and primary and secondary mirrors. PhaseCam systems can measure over long path distances despite air turbulence, and into environmental test chambers despite the heavy vibration from pumps associated with the chambers.
AccuFiz and FizCam Fizeau interferometers measure flat, concave and convex spherical optics, and can measure through view ports to test optics at cryogenic temperatures in vacuum chambers.
4D is proud to be one of the primary metrology partners in the development of the James Webb Space Telescope, and on dozens of other projects to explore space and understand our planet.
Added Technical Resources
Measurement of Space Optics and Structures
This paper presents an overview of the techniques and configurations used to build dynamic interferometers and measurement results for a variety of space-based optical components.
Vibrational Characteristics of Light-weight Mirrors
We present a technique to characterize and quantitatively measure the vibrational mode shapes and amplitudes of mirrors concurrently with surface figure testing..
Products for Space-based Optics
AccuFiz Fizeau interferometers can measure concave and convex spherical optics, with a wide range of reference optics to match test parts. High resolution systems like the AccuFiz 6MP can measure steep slopes.
4D PhaseCam Twyman-Green interferometers are the industry choice for measuring concave spherical optics, from several millimeters to tens of meters in diameter.
Short Coherence Fizeau for instantaneous measurements. Great for measuring parallel surfaces for surface figure and homogeneity. Also good for cryo and vacuum chamber separations.
NanoCam Sq 3D profilometer
Measure surface roughness and defects on smooth and supersmooth surfaces. As a dynamic instrument, it can take measurements anywhere on a large optic without worrying about vibration. Highly portable, and pick-and-place automation compatible.