Broad Bandpass optical glass filters made from Schott® colour glass and Hoya® colour glass have a transmission band surrounded by two blocking bands that allow only a portion of the spectrum to pass
giving 3-colour separation colour correction and high transmission centred around certain wavelengths. The measurement of the filter transmission to wavelength can be seen in the material data sheets. They are often used for infrared sensing systems and nightvision systems.
The ultraviolet, visible or infrared spectrum have broad spectral bandwidths. Bandpass filters are characterised by the fact that they connect an area of high transmission (Pass) shorter and longer wavelengths areas with lower transmission (blocking ranges).
The filters are lapped and polished to specified thickness to produce a given spectral transmission. These are available as custom and stock items.
Schott colour glass range of broad bandpass filters, in the visible, include Schott® BG-1, BG-3, BG-7, BG-12, BG-13, BG-14, BG-18, BG-23, BG-25, BG-26, BG-28, BG-34, BG-38, BG-39, BG-40, VG-4, VG-6, VG-9, VG-10, VG-14, RG-9.
Broadband filters in the UV Schott UG-1, UG-5, UG-11, BG-24A.
There are also blue, green and ultraviolet bandpass glasses made from Hoya glass filters.
Hoya U-330, U-340, U-360 transmit in the ultraviolet these are used as absorbing visible filters.
The IR bandpass filter Hoya RT-830 is a useful filter for infrared systems.
The Hoya filter range of bandpass blue filters and for colour separation include Hoya® B-370, B-380, B-390, B-410, B-440, B-460, B-480, G-530, G-545, G-550, LB-145.
Hoya colour compensating filters include Hoya® CC-500, CL-500, CAW-500, C-500, CM-500, CN-500.
Narrow bandpass filters are manufactured several ways. A combination of two Schott filters, or two Hoya filters or a coated glass and a glass filter can be used to produce a narrow band width. These filters are laminated together using optical adhesive creating a solid filter and offer a low cost option to coated narrowband pass interference filters.
Please see Custom for more information or Stock Bandpass Filters to order online.