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780/30nm Narrowband Interference Filter
780/30nm Narrowband Interference Filter is designed to transmit light centered 780nm and FWHM 30nm. Coligh manufactures EUV to IR narrow to wide bandpass filter.
It has features below:
- Center wavelength 780nm
- FWHM 30nm
- Transmission above 90%
- Blocking depth OD>=6
- ION Assisted Hard Coating
- Custom highly welcomed
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Hard-Coated 780/30nm Narrow Band Optical Filter for NIR Description
780/30nm Narrowband Interference Filter Coligh manufactures is a high-precision optical filter based on multilayer dielectric thin film interference technology, designed for spectral selective transmission in the 780 nm near-infrared band.
- The central wavelength is 780+/-1nm, covering the characteristic spectrum of semiconductor materials in the near-infrared biological tissue transmission window and the commonly used band of LiDAR.
- The half-bandwidth is 30+/-1nm, the passband range is 765–795 nm, and the 30 nm narrow bandwidth effectively suppresses interference from adjacent bands and improves the spectral resolution of the system.
- The cut-off depth OD>=6 in the range of 350-1000nm, strictly suppresses out-of-band ultraviolet, visible light and near-infrared stray light
- The transmittance in the passband is greater than or equal to 90%, maximizing the signal acquisition efficiency
- We use fused quartz as the substrate and use ion-assisted hard coating process to improve the adhesion and density of the film layer.
- We provide 7–10 day rapid prototype delivery, supporting flexible customization of any passband position, bandwidth, and size
780/30nm Narrowband Interference Filter Technical Datasheet
| Parameter | Specification |
| Center Wavelength (CWL) | 780nm ± 1 nm |
| Full Width at Half Maximum (FWHM) | 30nm± 1 nm |
| Peak Transmission | 90% |
| Blocking Range | 350-1000nm |
| Optical Density (OD) | OD ≥ 6 outside passband |
| Angle of Incidence (AOI) | 0° +/-5° |
| Surface Quality | 60/40 scratch-dig (per MIL-PRF-13830B) |
| Material Substrate | Fused Silica JGS1 |
| Coating Type | Hard-Coated Interference Filter/ IAD Assisted Coating |
| Thickness | 1mm (typical) |
| Filter Dimensions | Custom sizes available (e.g., Ø12.5 mm, 60×60 mm) |
| Clear Aperture | >90% of physical size |
| Operating Temperature | -40°C to +85°C |
780/30nm Narrowband Interference Filter Applications
- Biomedicine
NIR-II imaging requires the detection of the 780 nm emission signal of the probe, but the autofluorescence of biological tissues is generally less than 700 nm and the residual excitation light of 808 nm will interfere with the weak signal. The 780/30nm filter can be placed in front of the detector of the imaging system, allowing only the fluorescence signal of 765–795 nm to pass through, shielding the excitation light and background stray light. The 30 nm narrow-band pass window matches the probe emission peak, suppressing autofluorescence below 750 nm and ambient light above 800 nm. - Autonomous driving
LiDAR uses 780 nm laser to detect obstacles, but the high-intensity radiation of sunlight in the 750–800 nm band will cause point cloud noise and reduce the accuracy of target recognition. This filter covers the LiDAR receiving sensor and only allows the 780±15 nm laser echo signal to pass through. Block the bands other than 765–795 nm in sunlight to improve the signal-to-noise ratio - Environmental monitoring
Carbon monoxide has a weak absorption peak near 780 nm and needs to be detected by tunable laser absorption spectroscopy, but the absorption signals of water vapor and methane will interfere with the analysis. This filter can be built into the gas analyzer and work with the 780 nm distributed feedback laser to extract the 765–795 nm absorption signal. The 0 nm narrowband accurately matches the CO absorption peak, and deep blocking eliminates the influence of ambient stray light fluctuations. - Research field
The fluorescence emission peak of quantum dots CdSe/ZnS is near 780 nm, and the 405 nm Rayleigh scattering and stray light of the excitation light need to be filtered out. The 780/30nm bandpass filter can be used in the collection light path of the spectrometer as a supplement to the longpass filter to isolate the 765–795 nm fluorescence signal. Work in conjunction with the longpass filter to block the excitation light to extract the characteristic peaks of quantum dots.
