Bandpass Filters

This kind of  glass only transmits the light   within a narrow wavelengh range as  shown in figure. Its spectral   characteristic is composed of maximum  transmissivity (TM), wavelength of the   peak (λM ) , front-cut-off  wavelength,behind-cut-off wavelenght,and half-peak   width. The  wavelenght corresponding to the half of the maximum transmissivity   are  (λ2) and (λ1). And the half-peak width is determined by (λ2-λ1).    Front(behind)-cut-off wavelength is corresponding to the wavelength of＇zero＇transmissivity.But  there   are a few types which transmissivities of the behind-cut-off  wavelengthes   can't approach to zero,then they are determined by the  tranmissivity of the   certain wavelength.

              Spectrum Characteristic Curve Of Band-Pass Filter Glass

NO.

Type

Maximum
            Transmissivity
            (TM/λnm)

Behind Cut-off
            (T/λnm)

Behind cut-off
            (T/λnm)

Half-peak
            Width
            (λ2-λ1)(mm)

Thickness
            (mm)