Product Descriptions:
| Characteristics: | 645nm & 845nm Dual Bandpass Filter |
| Type: | Interference type Filter |
| Central Wavelength (CWL): | 645nm, 845nm |
| Full Width at Half Maximum(FWHM): | 40nm |
| Peak Transmittance(%) : | >92% |
| Optical Density (OD): | OD2 – OD3 |
| Shape: | Round, Square or customized |
| Color: | Red |
| Angle of Incidence(AOI): | 0° |
| Surface Quality: | 60/40 |
| Dimension(mm): | Customized, max. 300x300mm |
| Thickness(mm): | 0.21、0.3、0.55、0.7、1.0、1.1、1.5、1.8、2.0、3.0mm…etc. |
| Substrate: | Ultra-clear glass,K9,BK7,B270,D2637T, Quartz Glass(Fused Silica) or other specified. |
| Remark：Spectral range:350-1100nm. | |
Measured Spectral Graph – 645 & 845nm Dual Bandpass Filter:
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| Picture 1: 645 & 845nm Dual Bandpass Filters Spectral Graph measurement |
What is 645 & 845nm Dual Bandpass Filter?
A 645nm & 845nm Dual Bandpass Filter is an optical component that designed to transmit two specific wavelength ranges of 645nm red light and 845nm near infrared light.
Typically, it is widely used in surveillance cameras and intelligent traffic systems for day/night imaging without mechanical switching. Besides, it also serves multispectral imaging, machine vision and industrial inspection by enhancing detection accuracy while reducing system complexity and hardware costs.
What is key parameter when choose for right Dual Bandpass Filters?
When selecting a Dual Bandpass Filter, normally the following factors need to be taken into consideration：
- Central Wavelength (CWL)：Firstly, CWL is one of key parameter to designate, and it refer to the central wavelength at stable high transmission rate passband.
- Peak or Average Transmittance: typically T≥90%, however, Higher transmittance might need Anti-reflective(AR) coating.
- Full width at half maximum (FWHM): it 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): 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:
645&800nm Dual bandpass Filter, 35nm FWHM, Support Customized
Shenzhen Hengda Liyuan Optoelectronics introduced advanced optical vacuum technology that apply depositing nano-materials through ion-assisted evaporation onto a multilayer hard film in a high vacuum environment which coating layer is firm and has good tightness, and small bandwidth drift. Besides, Liyuan optoelectronics have been focus on optical coating for more than 17 years ,and the company offer one-stop optical filters solution including Narrow Bandpass Filters, IR cut-off Filters, Longpass Filters, Shortpass Filters, Notch Filters, ND filters, Star filters and Optical sapphire block.
