Bandpass filters allow a certain wavelength range to pass (passband) and block all other parts of the spectrum (stopbands). Thus, spectral ranges within the total spectrum can be separated.
LAYERTEC manufactures bandpass filters by combining
- • suitable substrates for blocking typical UV spectral ranges and
- • additional backside coatings for blocking enhancement e.g. in NIR/IR.
Such fabrications remain attractively priced if the error of the spectral position of the edge wavelengths remains above 0.5 % with respect to the wavelength under consideration. Likewise, the spectral slope of the edges T > 95 % to T < 0.1 % should not fall below two percent of the cut-off wavelength.