SCREEN: SCatteREr ENabled optical asymmetry

Optics that allow us to see clearly along one viewing direction while obscuring others' view of us are useful in numerous settings, including privacy-preserving window screens and one-way mirrors for psychological studies. Additionally, due to the rise of cameras that are able to see outside the visible spectrum, there is a need for optics that can also provide one-way visibility at these wavelengths. This is particularly challenging for thermal (i.e., infrared) imaging because most existing methods require precise control of scene illumination, which is difficult to achieve in the infrared. To address this challenge, we demonstrate broadband, passive one-way visibility by precisely tuning the position and optical parameters of a single optical scatterer. We show the benefits of our approach in both a simulated and an experimental testbed. With experimental data, we demonstrate a 5.22× and 5.23× improvement in the degree of asymmetry for midwave infrared (MWIR) and visible (VIS) wavelengths, respectively. Ultimately, our method introduces a robust, passive one-way visibility system at midwave infrared (MWIR), which can aid in numerous privacy preservation applications.