IR mirrors

Solaris Optics produces custom IR mirrors in its premises in Poland.
IR mirror (infrared mirror) is an optical element, which reflects infrared radiation from near-infrared (NIR) to far infrared (FIR) spectral range. Hence, infrared mirrors are typically covered by metallic coatings.

Metallic IR Mirrors

Typical metallic coatings for an infrared mirror include Aluminum, Silver and Gold. All those can be optionally covered with protective coatings, such as SiO or SiO2. Such layers provide mechanical and chemical protection, e.g. protect aluminum-covered IR mirror from oxidation.
Type of coating depends on a wavelength of a beam to be reflected:

  • NIR spectrum: Aluminum, Silver (optionally with SiO2 or Y2O3 protective coatings),
  • IR, FIR spectrum: Gold (optionally with SiO2 or Y2O3 protective coating).

Depending on the wavelength, an IR mirror reflects between 85% to 98% of incident light.
For mirrors with a metallic coating the reflection depends only slightly on actual wavelength variation, angle of incidence and polarization of an incoming beam.

Dielectric NIR Mirrors

Dielectric infrared mirrors are characterized by a higher reflectivity as compared to metallic infrared mirrors. For instance reflection may exceed 99.7% for 0 degrees incident angle. Dielectric layers are also more stable mechanically, hence protective layers may not be necessary.
Nevertheless the spectral range for a dielectric mirror is limited to NIR (800 to 1600 nm). Also behavior of a NIR dielectric mirror depends also on the angle of incidence, state of polarization, as well as on the actual wavelength.
We are happy to answer your questions regarding IR mirrors, so please do not hesitate to contact us !
See also:
Broadband dielectric and laser line mirrors
Thin film coatings