970nm Narrow-band Interference Filter FWHM 20nm
970nm narrow-band interference filter with a FWHM of 20nm is designed to transmit light centered at 970nm. Coligh manufactures EUV to 30000nm optical filters.
- Center Wavelength 970nm
- FWHM 20nm
- Tp>90%
- OD4 deep blocking depth
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970nm Narrow-band Interference Filter FWHM 20nm Description
970nm Narrow-band Interference Filter FWHM 20nm is a high-quality optical narrow-band filter.
- The central wavelength is 970+/-2nm with small tolerance and precise control. It is designed for applications that require high wavelength accuracy and matches specific molecular absorption peaks.
- The half-bandwidth is 20nm+/-2nm, and the spectral range covers 960nm-980nm, ensuring high selectivity of the target signal and avoiding interference from adjacent bands.
- The transmittance in the passband is greater than or equal to 90%, maximizing the effective optical signal intensity.
- It has an ultra-long cutoff band outside the passband, with a cutoff depth of OD4 in the range of 200-1700nm, which completely shields ambient stray light and thermal radiation noise.
970nm Narrow-band Interference Filter FWHM 20nm Datasheet
| Parameter | Specification |
| Center Wavelength (CWL) | 970 nm ± 2 nm |
| FWHM | 20 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 Wavelenth | 970/40nm， 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 |
970nm Narrow-band Interference Filter FWHM 20nm Application
- Plant detection
Water stress in plants will form a significant absorption peak at 970nm, and the traditional near-infrared band (900-950nm) cannot effectively distinguish between water and chlorophyll signals. The 970/20nm narrowband interference filter can accurately extract the characteristic wavelength of water at 970±10nm, suppressing the interference of chlorophyll reflection peak and atmospheric water vapor - Industrial film thickness monitoring
As the chip manufacturing process enters the 3nm era, traditional ellipsometers face defects such as slow measurement speed and insufficient sensitivity to transparent films. The 970/20nm filter can be used in interferometric measurement to match thinner films. - Blood oxygen monitoring
Blood oxygen detection needs to distinguish the absorption difference between deoxyhemoglobin (Hb) and oxyhemoglobin (HbO₂), but the traditional wide-spectrum light source is easily interfered by ambient light, resulting in a low signal-to-noise ratio. Deoxyhemoglobin has a main absorption peak at 760nm and a secondary absorption peak at 970nm, while oxyhemoglobin has the opposite absorption characteristics. Combined with the 970/20nm interference filter, deep tissues such as muscle and brain tissue can be monitored. - Industrial plastic sorting
Traditional sorting relies on manual or visible light imaging, but plastics such as PET and PVC have similar appearances but different recycling values, and require precise spectral differentiation. The 970/20nm filter only allows reflected light of 970nm±10nm to pass through, and filtering out interference from other wavelengths can increase the sorting speed.
