The invention relates to wavelength-selective optical filters for allowing
light of a narrow optical spectral band, centered around a wavelength
(.lamda..sub.c) to pass through them, while reflecting the wavelengths
lying outside this band. According to the invention, the transfer
function (T.sub.1,2(.lamda.)) of the component is defined by multiplying
two transfer functions of spectrally offset Fabry-Perot filters.