SCHOTT Optical Filter Glass is a non-crystalline, inorganic mixture of chemicals fused by heating with silica, boric or phosphoric oxides. These glasses have characteristics of selective transmittance, capable of passing certain light wavelengths, while being opaque to others. Due to their unique spectral properties, optical filter glasses are used in a wide variety of applications such as Fluorescence spectroscopy, Raman spectroscopy, and lithography, among many others.
Most optical filter glass falls into the following categories:
- Longpass Filters – block undesired, shorter wavelengths
- Bandpass Filters – selectively transmit a desired wavelengths
- Shortpass Filters – block undesired, longer wavelengths
- Neutral Density Filters – exhibit nearly constant transmission, especially in the visible range
With knowledge of your transmission and environmental requirements, Specialty Glass Products can assist with selecting the best filter glass to meet your needs. SGP can then CNC mill, cut, drill, lap, and polish the glass to many sizes, shapes, and surface finishes.
Longpass optical filter glasses allow long wavelengths to pass through and are characterized by the fact that a range of low transmission (blocking range) n the short wavelength range is joined to an area of high transmission (pass band) in the long wavelength range.
Longpass optical filter glasses are structured according to the following group names:
- GG – Nearly colorless to yellow glass, IR-transmitting
- OG – Orange glass, IR-transmitting
- RG – Red and black glass, IR-transmitting
- N-WG – Colorless glasses with different cutoffs in the UV, transmitting in the visible and IR ranges
At Specialty Glass Products, we offer the following SCHOTT longpass optical filter glasses:
Bandpass optical filter glasses selectively transmit a desired wavelength range and are characterized by the fact that they connect a region of high transmission (pass band) and shorter and longer wavelength ranges with low transmission (blocking ranges).
Bandpass optical filter glasses are structured according to the following group names:
- UG – UV-transmitting glass
- BG – Blue, blue-green, and multiband glass
- VG – Green glass
At Specialty Glass Products, we offer the following SCHOTT bandpass optical filter glasses:
NVIS Bandpass Filters – NVIS Glass with a special color and high optical density for Near IR*
Multi Bandpass Filter – light of several bands of wavelengths can pass through this filter
Shortpass optical filter glasses allow short wavelengths to pass through while long wavelengths are blocked. Typically, the slope at the transition between the pass band and blocking range of a longpass filter is much steeper than the slope of a shortpass filter.
Shortpass optical filter glasses are structured according to the following group name:
- KG – Virtually colorless glass with high transmission in the visible and high absorption in the IR ranges (heat protection filters)
At Specialty Glass Products, we offer the following SCHOTT shortpass optical filter glasses:
Neutral Density Filters
Neutral Density optical filter glasses exhibit nearly constant spectral transmittance in the range of visible light, for example from 400 nm to 800 nm, and are therefore only slightly wavelength dependent. Neutral density filters are perfectly grey in color.
Neutral Density optical filter glasses are structured according to the following group names:
- NG Grey glass with uniform attenuation in the visible range
At Specialty Glass Products, we offer the following SCHOTT Neutral Density optical filter glasses: