High-contrast apodization baffle for instruments onboard solar system exploration missions

We present concept and laboratory demonstration of high-contrast apodization baffle for instruments to be carried on exploration missions of the solar system. The primary science objective of the high-contrast baffle is to reveal escape of atmosphere on Mars, while other faint objects around blight sources are potential targets. We diverted heritages studied for exoplanet science and instrumentation to this work. The apodization in this work is realized by edge with microscopic Gaussian shaped structure. A simulation to confirm the concept and design of the high-contrast apodization baffle was carried out. Then, a baffle which was consisting of transparent flat substrate and thin film of aluminum on it was manufactured. The experiment was executed with He-Ne laser with wavelength of 633 nm. As the result, it was demonstrated that the apodization by the Gaussian edge is significantly working to improve the contrast. Achieved contrast is better than 10-6.5 and 10-8 in θ > 0.5 degree and θ > 1 degree, respectively. These results satisfy the requirement for remote sensing of the atmospheric less on Mars.