The spectrally selective optical properties of wavelength selective radiati
on emitters and filters based on periodically microstructured metal surface
s were investigated. Metal surfaces were structured by the use of a hologra
phic mask and subsequent etching processes. Due to the microstructure, ther
mally excited surface plasmons couple to electromagnetic radiation. Therefo
re a structured tungsten surface can act as a selective radiation emitter.
The calculation of the absorptance by a rigorous diffraction theory allows
the prediction of the emissivity of such structures. The angle dependent em
issivity of tungsten gratings with periods of 1.4 mu m and 2.0 mu m was mea
sured. A peak emissivity of 70% at a wavelength of 1.6 mu m was achieved. B
and pass filters for the near infrared spectral range based on perforated m
etal films were investigated theoretically and experimentally. Filters with
a grating period of 2.0 mu m were produced. A peak transmittance of 80% at
a wavelength 2.9 mu m was achieved. The optical properties of the diffract
ive elements described partly show a strong angle dependence.