Integrated Spatial Filter Array

To address the NASA Earth Science Division need for spatial filter arrays for amplitude and wavefront control, Luminit proposes to develop a novel Integrated Spatial Filter Array (iSFA) comprising integrated waveguides mapped with a pair of commercial lenslet arrays. Thousands of precisely spaced waveguides can be mass-produced with state-of-the-art photonic fabrication technology, which eliminates the tedious and error-prone alignment of up to a 1000 individual optical fibers in legacy fiber bundle SFA. The integrated waveguides are inherently polarization preserving. In Phase I, we designed and fabricated a 16-waveguide iSFA and demonstrated 22 dB polarization extinction ratio and superior coupling efficiency and uniformity over legacy fiber bundle SFA. In Phase II, we will tailor waveguide array parameters for optimum coupling with commercial lenslet arrays and fabricate a fully functioning prototype iSFA with 1,000 buried single-mode waveguide channels operating in a broad wavelength range in the 400-1,000 nm visible band. The iSFA will benefit NASA's Terrestrial Planet Finder mission for detection of earth-like planets, climates, habitability and life beyond our solar system.