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692/28nm Narrowband Filter
692/28nm Narrowband Filter is an optical filter designed to transmit light centered 692nm and FWHM 28nm. Coligh manufactures EUV to IR narrow and wide bandpass filter
It has features below:
- Center wavelength 692nm
- FWHM 28
- Transmission above 90%
- Blocking depth OD>=6
- ION Assisted Hard Coating
- Custom highly welcomed
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692nm ±14nm Narrowband Optical Bandpass Filter Description
692/28nm narrowband filter Coligh manufactures is a high-performance optical filter based on the principle of multilayer dielectric thin film interference, designed for precise selection of narrowband spectral near-infrared bands around 692 nm.
- The central wavelength is 692+/-1nm, covering the transmission window of biological tissues and the emission band of some near-infrared fluorescent markers.
- The half-bandwidth is 28+/-1nm, allowing light in the wavelength range of 678–706 nm to pass efficiently. The transmittance in the passband range is greater than or equal to 90%, and the cut-off depth OD>=6 in the range of 350-1000nm, deeply suppressing out-of-band ultraviolet, visible and near-infrared stray light.
- The extremely small tolerance of the central wavelength and half-bandwidth allows the filter batch to maintain an extremely consistent rate
- We use ion-assisted coating hard coating process to manufacture, and use low autofluorescence fused quartz as the substrate. The substrate is ultrasonically cleaned and plasma etched to remove surface contaminants to ensure the adhesion of the film layer.
- We welcome any customized optical filter projects, including coating, size, spectrum, etc.
692/28nm Narrowband Filter Technical Datasheet
| Parameter | Specification |
| Center Wavelength (CWL) | 692 nm ± 1 nm |
| Full Width at Half Maximum (FWHM) | 28nm± 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 |
692/28nm Narrowband Filter Applications
- In vivo near-infrared fluorescence imaging
In vivo imaging requires the detection of the emission signals of near-infrared fluorescent probes Cy5.5 and Alexa Fluor 680 at 680–710 nm, but the spontaneous fluorescence of biological tissues and ambient light noise will interfere with weak signals. The 692/28nm narrowband filter can be integrated in front of the detector of the imaging system, and with a 690 nm laser excitation light source, it only receives fluorescence signals of 692±14 nm. The 28 nm narrowband light window accurately matches the probe emission peak, suppressing tissue spontaneous fluorescence below 650 nm and ambient light above 700 nm. - Detection of metal residues on semiconductor wafers
In semiconductor manufacturing, the reflectivity of metal contamination copper and aluminum in the near-infrared band of 680–700 nm is significantly higher than that of silicon substrates, and high-contrast imaging is required to locate nano-level residues. The 692/28nm filter can be embedded in the optical module of the industrial camera, and with a 690 nm LED ring light source, it only receives 692 nm reflection signals. Blocking visible light and infrared thermal radiation in the workshop highlights the reflection characteristics of metal residues. - Non-invasive blood glucose monitoring
Near-infrared spectroscopy 680–720 nm can analyze blood glucose concentration through skin transmission light, but the absorption peaks of hemoglobin and water molecules are easy to interfere with the signal. The 692/28nm filter can be built into the optical probe of the blood glucose meter, and cooperate with the 690 nm LED light source to extract the 692 nm characteristic absorption signal. , The 28 nm bandwidth focuses on the blood glucose sensitive band and suppresses the interference of water molecules and hemoglobin. , Eliminate the influence of ambient light fluctuations - Surface Enhanced Raman Spectroscopy
In SERS detection, the intensity of the Raman signal at 692nm is extremely weak, and the Rayleigh scattering and fluorescence background of the excitation light need to be filtered out. This filter can be a supplement to the edge filter, placed in the collection light path of the Raman spectrometer, and isolate the 692 nm target signal. Work together with the long-pass filter to block 99.9999% of the excitation light (OD6) and extract weak Raman peaks.
