Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.
Diagram of the angle-dependent reflectance measurement (ARM) setup. The butterfly wing is positioned in the origin of a coordinate system determined by the two fibres, which rotate in the same vertical plane. The plane of the wing determines the horizontal plane of the coordinate system. The angles between the wing normal and the illumination and detection fibres are α and β, respectively. The wing is positioned so that its base corresponds to α = β = −90° and its apex to α = β = +90°
