1.Product Descriptions:
| Characteristics: | 940nm Bandpass Filter |
| Type: | Interference type |
| Central Wavelength (CWL): | 940+-5nm |
| Full Width at Half Maximum(FWHM): | 20/40/45/50/55/65/75/110nm |
| Peak Transmittance(%) : | BP940-20nm:>88% BP940-40nm:>85% BP940-45nm:>92% BP940-45nm Black Glass Substrate:>85% P940-50nm:>90% BP940-55nm:>90% BP940-65nm:>92% BP940-75nm:>92% BP940-110nm:>90% |
| Surface Quality: | 60/40 scratch-dig |
| Optical Density (OD): | OD2-OD3 |
| Color: | Black |
| Shape： | Square, Round, Irregular Shape |
| Dimension(mm): | specified** |
| Thickness(mm): | specified** |
| Substrate: | Ultra-clear glass,K9,BK7,B270,D2637T, Quartz Glass(Fused Silica) or other specified |
| Remark： Spectral range:350-1100nm *Customized capability: 380-2500nm, stock for 10nm intervals. **Common for 86x86mm, 80x80mm, other can customized, max. 300x300mm *** Thickness available: 0.21、0.3、0.55、0.7、1.0、1.1、1.5、1.8、2.0、3.0mm…etc. |
2.Measured Spectral Graph – 940nm Bandpass filter:
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| Picture 1: BP940-20nm Spectral Graph measurement |
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| Picture 5: Black Glass Substrate 940-40nm Bandpass Filter Spectral Graph measurement |
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| Picture 6: BP940-45nm Spectral Graph measurement |
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| Picture 7: BP940-45nm Black Glass Substrate Spectral Graph measurement |
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| Picture 8: BP940-50nm Spectral Graph measurement |
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| Picture 9: BP940-55nm Spectral Graph measurement |
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| Picture 10: BP940-65nm Spectral Graph measurement |
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| Picture 11: BP940-75nm Spectral Graph measurement |
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| Picture 12: BP940-110nm Spectral Graph measurement |
3.What is typical application for 940nm bandpass filters?
A 940nm bandpass filter is a high-precision optical element that only transmits light within a narrow spectral band centered at 940nm in the near-infrared region, while blocking all ultraviolet, visible light and other off-band near-infrared wavelengths. Typical applications for 940nm bandpass filters are very broad, include infrared sensing, infrared night vision cameras, facial recognition and access control systems. It also serves for laser ranging, industrial photoelectric detection, smart home sensors and medical optical devices. It filters out unwanted ambient light and interference, ensuring stable signal output and high detection accuracy.
4.What are key parameters when choose for a suitable Bandpass Filter?
When selecting a Narrow Bandpass Filter, normally the following factors need to be taken into consideration：
- Central Wavelength (CWL)：CWL is one of key parameter to designate first, it refer to the central wavelength at stable high transmission rate passband.
- Peak or Average Transmittance: typically ≥90%, Higher transmittance might need Anti-reflective(AR) coating.
- Full width at half maximum (FWHM): FWHM refer to the interval between the two wavelength points where the transmittance rate reaches 50%.
- Blocking rate: usually in terms of optical density(OD), OD2-OD3 for standard and higher will be OD4-OD6 per requirement.
- Angle of Incidence (AOI): AOI need to be considered as Interference Filter is angle sensitive, 0° AOI by default, other AOI e.g. 30/45° need to be specified.
- Physical and environmental requirement: Substrate type, dimensions and thickness, surface quality, and environmental durability.
Related products:
935nm Bandpass Filter, 935nm CWL, 40nm FWHM, OD2,unmounted optical infrared bandpass filter
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