Band-Pass Filter Glass

This kind of glass only transmits the light within a narrow wavelength range as shown in figure. Its spectral characteristic is composed of maximum transmissivity (TM) wavelength of the peak (lM), front-cut-off wavelength, behind-cut-off wavelength, and half-peak width.


The wavelength corresponding to the half of the maximum transmissivity are l2 and l1. And the half-peak width is determined by l2 - l1. 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 transmissivity of the certain wavelength.
Band-pass filter glass is named DTB, and wavelength of the peak is used as its serial number.

Spectrum Characteristic Curve of Band-Pass Filter Glass 

Technical Indexes 

No. Type Maximum Transmissivity
(TM/λMnm)
Front Cut-off
(T/λnm)
Behind Cut-off
(T/λnm)
Half-peak Width
(λ2-λ1)(nm)
Thickness (nm)
1 DTB400 >45/400+/-2 0/320+/-5 0/525+/-5 <90 2
2 DTB435 >48/435+/-2 0/340+/-5 <2.0/540+/-5 <100 4
3 DTB470 >40/470+/-2 0/340+/-5 0/600+/-5 <115 4
4 DTB500 >48/500+/-2 0/380+/-5 0/630+/-5 <100 4
5 DTB530 >48/530+/-2 0/420+/-5 0/670+/-5 <95 2
6 DTB545 >48/545+/-2 0/400+/-5 0/720+/-5 <100 4
7 DTB560 >40/560+/-2 0/435+/-5 0/725+/-5 <104 4
8 DTB600 >36/600+/-2 0/470+/-5 <1.0/800+/-5 <95 4
9 DTB660 >44/660+/-2 0/500+/-5 <2.0/800+/-5 <115 4
10 DTB700 >28/700+/-2 <0.5/570+/-5 <2.0/820+/-5 <95 4
11 DTB720 >50/720+/-2 0/500+/-5 <9.0/900+/-5 <140 4
12 DTB740 >25/740+/-2 0/650+/-5 <4.0/900+/-5 <85 4
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