Optical metrology for wide field-of-view remote sensing systems

For high-throughput remote sensing systems, wide field-of-view optical designs utilizing freeform or non-traditional optical surfaces are increasingly being introduced and developed. Manufacturing these enabling optical components and integrating them effectively requires optical metrology solutions to guide fabrication and assembly processes. Interferometry measures the optical path difference between test and reference beams by analyzing phase-shifted interferograms. This technique requires a null configuration setup, often employing null lenses or computer-generated holograms (CGHs), and is suitable for various surfaces, including flat, spherical, aspheric, and freeform mirrors. Deflectometry, on the other hand, measures surface slope distributions by analyzing light reflections off the optical surface using a series of camera images. This method captures the irradiance distribution to determine local surface slopes, which are then integrated to reconstruct the surface height map. It offers high precision and a broad dynamic range, making it suitable for a wide range of optical surface types. Together, these techniques provide advanced capabilities for the development and deployment of wide field-of-view remote sensing systems, paving the way for future space innovations.