970/40nm Bandpass Interference Filter
970/40nm bandpass interference filter is an optical filter that transmit light around 970nm and with FWHM 40nm. Coligh manufactures EUV to 30000nm bandpass filter.
- Center Wavelength 970nm
- FWHM 40nm
- Tp>90%
- OD4 deep blocking depth
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970/40nm Optical Bandpass Interference Filter Description
970/40nm Bandpass Interference Filter is an optical filter designed for near infrared.
- We use advanced hard-coating interference coating technology to accurately select the target band of 970nm ±20nm, while deeply suppressing out-of-band stray light.
- The central wavelength is 970+/-2nm, matching the near-infrared absorption/reflection characteristics
- The half-bandwidth is 40+/-4nm, forming high transmittance in the range of 950-990nm. Adapt to the scene of light source wavelength drift or wide absorption peak.
- The transmittance in the transmission band is greater than or equal to 90%, maximizing signal utilization
- It has an ultra-wide cut-off range, with a cut-off depth of OD4 in the range of 200-1700nm, completely eliminating ambient light interference. Suppress thermal radiation noise.
970/40nm Bandpass Interference Filter Technical Datasheet
| arameter | Specification |
| Center Wavelength (CWL) | 970 nm ± 2 nm |
| FWHM | 40 nm ± 2nm |
| Peak Transmission | ≥ 90% |
| Blocking Range | 200 – 1700nm |
| Optical Density (OD) | OD4 |
| Angle of Incidence (AOI) | 0° |
| Clear Aperture | >90% of the diameter |
| Substrate Material | UV Fused Silica, K9,sapphire, Other optical glass |
| Size | Ø12.7mm, Ø25.4mm,Ø50.8mmor customizable |
| Environmental Durability | Compliant with MIL-STD-810G |
| Other available wavelength | 970/20nm, 970/60nm |
| Custom Option | EUV to 30,000nm |
| Filter Type | Multilayer Interference Bandpass Filter |
| Coating Technology | Ion-Assisted Deposition (IAD), Hard coated |
| Surface Quality | 80-50, 60-40, 40-20 (per MIL-PRF-13830B |
970/40nm Bandpass Interference Filter Applications
- Biomedicine
Deoxyhemoglobin (Hb) has absorption differences at 760nm and 970nm. Using a 970/40nm bandpass filter, blood oxygen saturation can be calculated by the ratio of reflected/transmitted light intensity. In addition, the 40nm bandwidth is compatible with the wavelength drift of lasers or LED light sources, reducing the dependence on light source stability. - Plastic material sorting
PET has a significantly higher reflectivity at 970nm than PVC. The 970/40nm filter can be used to extract the difference in 970nm reflection signals when sorting PET and PVC. The 40nm bandwidth is suitable for wide-angle imaging of high-speed sorting machines, reducing the impact of spectral shift caused by conveyor belt vibration. - Water quality detection
When 970nm light penetrates water, the scattering and absorption characteristics can be associated with turbidity and dissolved organic matter content. The 970/40n optical filter can cover the wide absorption band of organic matter in water and improve detection stability. - Spectrometer
The 970/40nm filter is used as the core filter component to separate the 970nm characteristic signal for material composition analysis and is suitable for portable spectrometers.
