Wide Range Chromatic Interferometric Probe

From flagship observatories to small earth-observation satellites, many NASA missions require high performance optical components that are also cost-effective to manufacture and launch. Freeform optical components can reduce a telescope#39;s size and weight (reducing launch costs), but are challenging to test and validate with traditional metrology tools due to their lack of symmetry and large changes in curvature (increasing manufacturing costs). Improved metrology systems for freeform optics have potential to improve performance and reduce manufacturing costs by avoiding prescription-specific null correctors or holograms. Metrology systems for freeform optics require a challenging combination of capabilities: high-resolution (ideally sub-nanometer) measurement of large deviations from a planar surface and steep surface slope. At OptiPro Systems, we have recently developed (in part through NASA SBIR projects) a chromatic interferometric probe capable of sub-nanometer metrology of optical surfaces, which is essential for precision optical components such as telescope mirrors. The probe#39;s range is currently limited to small surface sag (quot;measurement rangequot;) and shallow surface slope (quot;acceptance anglequot;), preventing direct application to freeform optics.nbsp;We propose fundamental enhancements to the chromatic interferometric probe to enable cost-effective metrology of freeform optics: wide measurement range and acceptance angle, while maintaining sub-nanometer performance. Such improvements require understanding unproven concepts and potentially major redesign of the probe optical system. The Phase I project aims to verify these concepts, using bread-board level proof-of-concept demonstration and computer simulations, and deliver a report detailing a clear path toward implementing these improvements in prototype probes and their use in metrology of high-performance freeform optics.