Metal Mesh Filters in the Far Infrared Region

Abstract

The transmittance and reflectivity of metal meshes made of brass wire were measured in the far infrared region. The reflectivity of these meshes is very low in the wavelength region up to the wavelength of about 1.3 times the mesh constant, but then increases steeply so that the mesh becomes a nearly perfect reflector beyond the wavelength of about twice the mesh constant. This reflecting property is excellent for a reflection filter, compared with the usual far infrared filters.