Collection: Longpass Filter (LPF)

Longpass Filters (LPF) - Superior Long Wavelength Transmission

Longpass filters transmit longer wavelengths while effectively blocking shorter wavelengths, providing essential spectral control for applications requiring the removal of unwanted short wavelength components.

LP790 Longpass Filter (T>95%@795-1200nm, OD5@600-785nm)
$50.00
CUT-ON: 790nm
LP795 Longpass Filter (T>90%@815-1200nm, OD3@200-785nm)
$50.00
CUT-ON: 795nm
LP800 Longpass Filter (T>85%@810-1750nm, OD5@200-790nm)
$50.00
CUT-ON: 800nm
LP825 Longpass Filter (T>85%@835-1750nm, OD5@200-815nm)
$50.00
CUT-ON: 825nm
LP830 Longpass Filter (T>90%@840-1200nm, OD4@200-815nm)
$50.00
CUT-ON: 830nm
LP835 Longpass Filter (T>95%@845-1800nm, OD4@200-820nm)
$50.00
CUT-ON: 835nm
LP840 Longpass Filter (T>90%@850-1800nm, OD5@200-810nm)
$50.00
CUT-ON: 840nm
LP850 Longpass Filter (T>85%@860-1750nm, OD3@200-840nm)
$50.00
CUT-ON: 850nm
LP900 Longpass Filter (T>90%@915-1100nm, OD4@200-890nm)
$50.00
CUT-ON: 900nm
LP940 Longpass Filter (T>85%@950-1100nm, OD2@350-930nm)
$50.00
CUT-ON: 940nm
LP950 Longpass Filter (T>85%@960-1750nm, OD5@200-940nm)
$50.00
CUT-ON: 950nm
LP975 Longpass Filter (T>85%@910-1750nm, OD5@200-965nm)
$50.00
CUT-ON: 975nm
LP900 Longpass Filter (T>85%@910-1750nm, OD5@200-890nm)
$50.00
CUT-ON: 900nm
LP980 Longpass Filter (T>85%@990-1100nm, OD2@350-970nm)
$50.00
CUT-ON: 980nm
LP1000 Longpass Filter (T>85%@1015-1750nm, OD5@200-990nm)
$50.00
CUT-ON: 1000nm
LP1040 Longpass Filter (T>85%@1050-1750nm, OD5@200-1020nm)
$50.00
CUT-ON: 1040nm
LP1200 Longpass Filter (T>85%@1210-1750nm, OD5@200-1190nm)
$50.00
CUT-ON: 1200nm
LP1300 Longpass Filter (T>90%@1380-2200nm, OD3@200-1250nm)
$50.00
CUT-ON: 1300nm
LP1400 Longpass Filter (T>85%@1420-1750nm, OD4@200-1380nm)
$50.00
CUT-ON: 1400nm
LP1600 Longpass Filter (T>85%@1620-2000nm, OD4@200-1580nm)
$50.00
CUT-ON: 1600nm

What is a Longpass Filter

Longpass Filter allow longer wavelength to pass through while blocking shorter wavelength.

For example a LP550 Filter allow 560-1200nm to pass through, while blocking 200-540nm light.

Use below interactive demo to simulation longpass filter with different cut-on wavelength.

  • Cut-on Wavelength

    Cut-on wavelength is the point where the filter reach 50% of its peak transmission ratio.

  • Transmit Region

    The region where longpass filter suppose to let light pass through.

  • Tranmission Ratio

    The transmission ratio in the transmit region, usually it is an average value over an area.

  • Blocking Region

    The region where light supposed to be blocked.

  • Optical Density

    To evaluate the attenuation in the blocking region. For example OD3 means there should be less than 0.1% light to go through in blocking region.

  • Transition Area

    The wavelength range between Blocking Region to Transmit Region. Smaller transition area means a better longpass filter.

    Usually it will be 2nm - 30nm.

Frequently Asked Questions

Difference between Longpass Filter and Bandpass Filter

Longpass filter allow a big range of light to go through. This is useful when you need more light range or intensity to pass through.

Longpass Filter VS Shortpass Filter

Shortpass filter allow shorter wavelength to pass through, While longpass filter allow longpass to go through.

This also means, when you need range UV-VIS light to pass through, most cases you will use a shortpass filter.

When you need VIS-NIR light to pass through, you will need a longpass filter.

What is the application of longpass filter?

Longpass filter oftenly used in Fluroscence, Machine Vision, and Raman.

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