Band-pass filter glass referred to as band-pass glass is a kind of glass with narrow bandwidth and obvious cutoff of short and long waves, as shown in the figure. Their spectral characteristics are represented by the maximum transmittance (TM) and its wavelength (λ M) position, short-wave cutoff wavelength, long-wave cutoff wavelength and half-width.

The difference between wavelength λ 1 and λ 2 corresponding to half of the maximum transmittance of bandpass glass (λ 1-λ 1) nm is called half width. The shortwave cutoff wavelength is at the peak shortwave side and the transmittance is equal to zero. The long-wave cutoff glass length is at the peak long-wave side, and the transmittance is equal to zero. In some varieties, when the glass transmission Prida is less than zero on the long-wave side, it is expressed as the transmittance of a certain wavelength. Bandpass glass is named after the first letter DTB of Hanyu Pinyin, and the wavelength position of the maximum transmittance is used as their serial number.

一.Cutoff piece

Technical requirements of UV cut-off glass
Card number	Thickness	λtj	λ0	Tλ0	K
	(mm)	(nm)	(nm)	(%)
*ZJB220	2	220±10	300	≥89.5	≥0.5
*ZJB240	2	240±10	330	≥89.5	≥0.5
ZJB260	2	260 ±10	340	≥89.5	≥0.5
ZJB280	2	280±10	350	≥89.5	≥0.5
ZJB300	2	300±10	350	≥89.5	≥1.0
ZJB320	2	320±10	400	≥89.5	≥1.0
ZJB340	2	340±10	420	≥88.0	≥0.8
ZJB360	2	360±10	440	≥87.0	≥1.0
ZJB380	2	380±10	500	≥86.0	≥0.8

二.Visible bandpass filter

Visible broadband glass
Card number	Thickness	420	500	600	700	800	900	1000	1060	2200
	(mm)	(nm)	(nm)	(nm)	(nm)	(nm)	(nm)	(nm)	(nm)	(nm)
GRB1	3	≥85.0			45.0~70.0			≤4.0
GRB2	2	365≥83.7	≥83.7	≥80.0	≤61.9	≤30.0	≤9.1		≤1.8
GRB3	2	365≥81.9	≥81.0	≥76.4	≤50.6	≤12.9	≤2.8		≤0.1	≤0.9

三.Ultraviolet bandpass filter

Technical requirements for ultraviolet transmission visible absorption glass
Card number	Thickness	254	280	313	334	365	405	700
	(mm)	(nm)	(nm)	(nm)	(nm)	(nm)	(nm)	(nm)
ZWB1	1		≥50.0	≥81.0			≤1.0	≤30.0
ZWB2	1			≥38.0		≥80.0	≤8.0	≤14.0
ZWB3	2	≥50.0			≥86.0		≤28.8	≤64.6

四.Attenuation sheet