Skip to content 
7900nm (7.9μm) Infrared Optical Longpass Filter
7900nm infrared optical longpass filter is designed to transmit wavelength longer than 7900nm and block others. Coligh manufactures infared longpass filters.
- 50% Transmission Wavelength at 7900 nm
- >80% High Transmission
- Broadband Blocking and Transmission
- Insensitive to Angle of Incidence
- Hard First-Surface Dielectric Coating
Products Categories
Get A Free Quote
7300nm Infrared Longpass Optical Filter Description
7900nm (7.9μm) Infrared Optical Longpass Filter Coligh manufactureed is a high-performance optical filter based on hard dielectric multilayer interference technology
- 50% cut on wavelength is 7900nm, strictly define the spectral demarcation point, ensure that signals above 7.9μm pass efficiently, and short-wave interference is accurately cut off.
- In the range of 8200nm-11000nm, the transmittance is greater than or equal to 80%, wide-band transmission, suitable for far-infrared thermal imaging, trace gas detection needs, maximize the retention of far-infrared thermal radiation, gas absorption peaks and other useful signals.
- In the range of 1500nm-7300nm, the cut-off depth is OD2, and the transmittance is less than or equal to 1%, effectively suppressing mid-infrared noise
By optimizing the refractive index gradient of the film system, we can avoid spectral shift or signal attenuation caused by angle shift when the incident angle is larger.
7900nm Infrared Optical Longpass Filter Technical Datasheet
| Parameter | Specification |
| Cut‑on Wavelength (50% T) | 7900nm |
| High‑Transmission Band | ≥ 80% @ 8200nm-1100nm |
| Blocking Region | 1500-7300nm |
| 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, Ø50mm, Ø100 mm or custom |
| Thickness | 0.5mm, 1.0mm or custom |
