Band pass filter are used to transfer energy within a predetermined, strictly limited wavelength range and to prevent energy transfer outside of this range. Band pass filters generally consist of specially arranged interference layer stacks. These are combined with further layer systems and coloured glasses or other absorbent materials to produce the requested spectral function.

Band-pass with central wavelength @ 798nm and FWHM Dλ = 30nm on coloured glass as substrate (suppression of VIS)