Experimental characterization of a silicon nitride photonic crystal light sail

Abstract

The Breakthrough Starshot Initiative, established in 2016, aims to propel an ultra-lightweight spacecraft to Alpha Centauri using radiation pressure from a high-power, ground-based laser. Nanopatterned silicon nitride has been proposed as a candidate material for the laser sail. In this work, we design and fabricate a silicon nitride photonic crystal with high reflectivity around a laser wavelength of 1064 nm. We demonstrate the ability to shift the resonant features of the laser sail using titanium dioxide coatings and increase the longwave infrared emissivity using polymer coatings. We also characterize the response of the sail to temperature and optical power.