ALEXANDRIA, Va., April 15 -- United States Patent no. 12,601,861, issued on April 14, was assigned to Pixieray Oy (Espoo, Finland).
"Index matching based on gas to liquid phase change" was invented by Klaus Melakari (Espoo, Finland).
According to the abstract* released by the U.S. Patent & Trademark Office: "Disclosed is an optical element with a first substrate and a second substrate. A cavity is formed between first substrate and second substrate; a material, wherein liquid state of material has refractive index that matches refractive index of at least one of: first substrate, second substrate; a liquid reservoir that is to be employed to hold liquid state; a gas reservoir that is to be employed to hold a gaseous state of the material;...