Bandpass Filters

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.

Fig.1:Bandpass filter for 1500 – 1600 nm

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.