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10400nm (10.4μm) Infrared Longpass Optical Filter
10.4μm infrared longpass optical filter is designed to transmit longer wavelength than 10.4μm and block shorter. Coligh manufactures infared longpass filter.
- 50% Transmission Wavelength at 10400 nm
- >90% High Transmission
- Broadband Blocking and Transmission
- Insensitive to Angle of Incidence
- Hard First-Surface Dielectric Coating
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long-wave Infrared Longpass Filter With 10400 nm Cut-on Wavelength Description
10400nm infrared longpass optical filter is specially designed for long wave infrared range 8-14μm. It can ensure efficient transmission of infrared radiation ≥10.4μm, while strictly blocking stray light interference of visible light, near infrared and mid-infrared stray light.
- 50% transmittance is located at 10.4μm, ensuring efficient use of the target band. It can accurately separate far-infrared signals
- In the range of 10500-15000nm, the transmittance is greater than or equal to 90%, and the support of wide passband improves the sensitivity and utilization of infrared signals.
- In the range of 1500-9700nm, the cutoff depth is less than 1% transmittance, that is, greater than OD2, which can effectively filter out visible light, near infrared and mid-infrared noise
10400nm Infrared Longpass Optical Filter Technical Datasheet
| Parameter | Specification |
| Cut‑on Wavelength (50% T) | 10400nm |
| High‑Transmission Band | ≥ 90% @ 10500nm-15000nm |
| Blocking Region | 1500nm-9700nm |
| Optical Density (OD) | OD >2 (T < 1%) |
| Substrate Materials | White glass, Sapphire, Silicon, Fused Silica, Zinc Selenide |
| Coating Type | Hard first‑surface all‑dielectric |
| Surface Quality | 80-50, 60‑40, 40-20 scratch‑dig (MIL‑PRF‑13830B) |
| Clear Aperture | ≥ 90% of full aperture |
| Available Diameters | Ø12.7 mm, Ø25.4 mm, or custom |
| Thickness | 2.0mm or custom |
10400nm Infrared Longpass Optical Filter Technical Applications
- CO₂ laser system
The operating wavelength of CO₂ laser is 10.6μm, but there may be short-wave visible light or near-infrared stray light from the pump source or ambient light in the system, which will interfere with laser transmission or damage optical components. The 10400nm infrared long-pass filter can strictly block all non-laser wavelengths <10.4μm, allowing only 10.6μm laser to pass efficiently, while serving as a protective window to protect the laser cavity. This can improve the accuracy and energy utilization of laser processing (cutting, welding). - Thermal imaging and military
Thermal imaging relies on the 8-14μm thermal radiation of the target object, but short-wave radiation such as sunlight and light will reduce image contrast, especially in complex environments. 10800nm long-pass filter can filter out interference light <10.4μm, only transmit far-infrared heat signals, and enhance target recognition capabilities at night or under haze conditions - SF₆, CH₄ industrial gas monitoring
CH₄ and SF₆ have characteristic absorption peaks in the far infrared at 10.7μm, but light of other wavelengths will cause spectral data distortion. This filter can block visible light and mid-infrared light in non-target bands, and only allow light of 10.4–14μm to pass through, matching the gas absorption spectrum. Improve gas detection sensitivity and accuracy,
