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Bandpass or Longpass Colored Glass Filters

Optical filters selectively transmit light in a specific range of wavelengths, while blocking the remaining wavelengths. Filters can be broad transmitting large wavelength ranges or very specific & targeted only to a few wavelengths. Bandpass Filters transmit a band of wavelengths while blocking the wavelengths on either side of that band. The opposite of a bandpass filter is a notch filter which blocks a specific band of wavelengths. Longpass filters transmit wavelengths longer than the specified cut-on wavelengths and block the shorter wavelengths. Shortpass filters are opposite and transmit the shorter wavelengths. Optical glass filters are widely used in safety glasses, industrial measurement, regulation technology and environment protection.

Due to its selective absorption in visible wavelength range, colored glass filter exhibits various color depending the glass type. Colored glass filters are used to selectively transmit certain wavelength ranges and block others or to reduce the amount of heat transmitted through the system. They are categorized into longpass filters, shortpass filters, bandpass filters, heat absorbing and neutral density filters. Colored glass filters provide an economical filter for various applications.

Paralight Optics offers colored glass filters fabricated from different types of Schott® glass: longpass filters including ultra-violet (WG280, WG295, WG305, WG320), golden Yellow color (GG395, GG400, GG420, GG435, GG455, GG475, GG495), orange color (OG515, OG530, OG550, OG570, OG590), red color (RG610, RG630, RG645, RG665, RG695, RG715) and black color (RG780, RG830, RG850); bandpass filters including UV transmitting & VIS absorbing (UG1, UG5, UG11), green color (VG9), blue color (BG3, BG7, BG18, BG25, BG36, BG38, BG39, BG40); neutral density filters (neutral glass with uniform attenuation in the visible range): NG1, NG3, NG4, NG5, NG9, NG11; Heating Absorbing (Colorless glass with high transmission in the visible and absorption in the IR range): KG1, KG2, KG3, KG5. These colored glass filters are available in both round and square shapes, either uncoated or specifying your coating. Please check the following graphs for bandpass colored glass filters with a broadband antireflective coating designed for either the 245 – 400 nm or 350 – 700 nm wavelength range, which is deposited on both surfaces of a Schott® glass substrate that has been selected for its high transmission in the ultraviolet or visible.



Shapes Options:

Different Sizes of Round or Square Options

Economic Alternative:

To Thin-Film Interence Filters for both Longpass and Bandpass

Coating Options:

AR Coated (245 - 400 nm or 350 - 700 nm) for Dielectric Broadband Filters

Optical Performance:

Transmission Greater than 90% in the above Specified Range


Common Specifications:



Ranges & Tolerances

  • Substrate Material

    Schott® Colored Glass

  • Type

    Bandpass colored glass filter

  • Size

    Round: Ø25 mm / Square: 2" x 2" / Square: 6" x 6"

  • Diameter Tolerance

    +0.00/-0.20 mm

  • Length and Width Tolerance (Square)

    +0.00/-0.20 mm

  • Parallelism

    ≤5 arcmin

  • Surface Quality (scratch-dig)

    80 - 50

  • Surface Flatness (Peak-Valley)

    < 2 λ @ 632.8 nm

  • Clear Aperture

    >90% of Diameter (Round), >90% of Dimension (Square)



◆ The First 2 Transmittance Curves for FGUV5, FGUV11 Bandpass Colored Glass Filters, AR Coated: 245 - 400 nm (The recommended range is the range for which the wavelength-dependent transmission is >50% of the peak transmission)
◆ The Last 2 Transmittance Curves of FGS900, FGB37 Bandpass Colored Glass Filters, AR Coated: 350 - 700 nm (The recommended range is the range for which the wavelength-dependent transmission is >50% of the peak transmission)
◆ For more detailed information on coatings of other types of colored glass filters, please contact us.


Transmittance Curve of FGUV11 Bandpass (245 - 400 nm) Colored Glass Filters


Transmittance Curve of FGS900 Bandpass (350 - 700 nm) Colored Glass Filter


Transmittance Curve of FGB37 Bandpass (350 - 700 nm) Colored Glass Filter