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9700nm Infrared Filter Longpass
9700nm Infrared Filter Longpass is longpass filter to transmit wavelength longer than 9700nm and block the shorter. Coligh manufactures infared longpass filter.
- 50% Transmission Wavelength at 9700 nm
- >90% High Transmission
- Broadband Blocking and Transmission
- Insensitive to Angle of Incidence
- Hard First-Surface Dielectric Coating
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9700 nm Infrared Longpass Optical Filter Description
9700nm (9.7μm) infrared long-pass filter) is an optical filter designed for far-infrared light with a transmission wavelength of ≥9.7μm based on hard multilayer dielectric film interference technology
- 50% of the emission wavelength is precisely controlled within 9700nm±100nm, and the transmittance is greater than or equal to 90% at 10100-15000nm. It is suitable for efficient collection of signals such as far-infrared thermal radiation and gas absorption peaks, and can be compatible with a variety of far-infrared detectors
- The cut-off depth of 1500-9500nm outside the passband is greater than OD2, and the transmittance is less than 1%. It can effectively eliminate mid-infrared interference
9700nm Infrared Filter Longpass Technical Datasheet
| arameter | Specification |
| Cut‑on Wavelength (50% T) | 9700nm+/-100nm |
| High‑Transmission Band | ≥ 90% @ 10100nm-15000nm |
| Blocking Region | 1500nm-9500nm |
| 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 |
9700nm Infrared Filter Longpass Applications
- Metal smelting, ceramic sintering
The thermal radiation peak of molten metals such as molten steel and aluminum is at 8-14μm, but the short-wave radiation in the furnace will interfere with the accuracy of infrared temperature measurement. The 9700nm long-pass filter filters out short-wave noise <9.7μm and transmits 9.7-15μm thermal radiation signals to improve temperature measurement accuracy. This can control the smelting error - Terahertz imaging
Terahertz waves need to shield mid-infrared noise <10um in security inspection and biomedical imaging to improve imaging contrast. The 9700nm optical long-pass filter can cut off mid-infrared interference <9.7μm, transmit terahertz signals, and adapt to silicon-based terahertz detectors to ensure imaging purity. - Calibration of aerospace thermal control systems
Satellite thermal control coatings need to simulate space blackbody radiation >10μm in the laboratory, but the short-wave component of the calibration light source will introduce errors. This filter can filter out the non-thermal radiation band <9.7μm and transmit the 9.7-14μm blackbody radiation spectrum to ensure calibration accuracy.
