Bandpass Filter Glass

Bandpass filter glass

Band-pass glass is a kind of glass with relatively narrow bandwidth and obvious cutoff between short and long waves, as shown in the figure. Their spectral properties are represented by the maximum transmittance (TM) and their wavelength (λM) position, short-wave cutoff wavelength, long-wave cutoff wavelength, and half-width.

Half of the maximum transmittance of the band-pass glass corresponds to the difference between the wavelengths λ1 and λ2 (λ1-λ1)nm called the half-width. The shortwave cutoff wavelength is the wavelength on the peak shortwave side where the transmittance is equal to zero. Long wave cutoff glass length is the wavelength at the peak long wave side, the transmission ratio is equal to zero, and some varieties, the transmission ratio of the glass on the long wave side is less than zero, and it is expressed by the transmission ratio of a certain wavelength. Band-pass glasses are named after the first letter of Chinese pinyin, DTB, and the wavelength position value of the maximum transmittance is taken as their serial number.