Product Descriptions：
| Characteristics: | BP650-40nm Bandpass Filter |
| Type: | Interference type |
| Color: | Red |
| Central wavelengths(CWL)： | 650nm |
| Average Transmissivity(%): | 90% |
| Optical density: | OD2 or customized |
| Shape : | Square or customized |
| Dimension(in mm): | 17x17mm |
| Thickness(mm): | 1.0mm or customized |
| Material: | Optical Glass |
| Spectral range: | 350-1100nm |
| Remark: (1) Shape: Rectangle, Square or customized (2) Common for 86x86mm, 80x80mm, max. 300x300mm (3) Optional thickness: 0.21、0.3、0.55、0.7、1.0、1.1、2.0、3.0mm…etc. | |
What is the BP650-40nm Bandpass Filter?
The BP650-40nm Bandpass Filter is an optical component designed to allow a specific band of red light centered at 650 nm to pass through while blocking other wavelengths. The 40nm in its name refers to its bandwidth, so the nominal passband range for this filter is 630-650nm.
What is the typical application for 650nm Bandpass filter?
The BP650-40nm Bandpass filter provides a practical balance between precise red light wavelength selection and tolerance to real world spectral bandwidth, making it useful in consumer electronics, medical sensing, fluorescence imaging, machine vision, industrial inspection, and analytical instrumentation：
- Biometric recognition: iris and face recognition systems.
- Fluorescence imaging: useful for red-emitting fluorophores.
- Pulse oximetry and biomedical sensing: targets red-light absorption/transmission bands relevant to hemoglobin.
- Barcode scanning and laser range finding: transmits 650 nm laser light while rejecting ambient light.
- Medical and analytical instruments: spectrophotometers, colorimeters, chemical analyzers, and diagnostic equipment.
- Machine vision: improves contrast in automated inspection and robotic guidance.
- Industrial sorting: material sorting based on red-light reflectance/transmission differences.
- Laser cleanup: removes unwanted side modes or pump light from 650 nm laser systems.
In different applications, the actual transmission, blocking depth, material substrates and environment durability depend on the specific manufacturer’s specifications.
Spectral measurement graph
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Picture 1: 650 nm Bandpass Filter Spectral Measurement |
What are key parameters when choose for a suitable Bandpass Filter?
When selecting 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:
640nm Bandpass Filter, 640nm CWL,20nm FWHM,Support Customized
660nm Bandpass Filter, 660nm CWL,10/30/40/70/75nm 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. The company 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.
Remark：Because the interference type filter varies its performance at different angles, the spectral parameters usually determine its appearance color; moreover, the pictures in this link may originate from various shooting angles, so the actual color should therefore rely on the final spectral parameters required as the standard.
