Product Descriptions:
| Characteristics: | 780nm Longpass Filter |
| Type: | Interference type filter |
| Cut-off Wavelength(CWL): | 780nm |
| Average Transmittance(%) : | >92% |
| Optical Density (OD): | OD2 |
| Shape: | Round, Square or customized |
| Color: | Silver |
| Surface Quality: | 60/40 scratch-dig |
| Dimension(mm): | Customized* |
| Thickness(mm): | Customized** |
| Substrate: | Optical Glass *** |
Remark：Spectral range:350-1100nm *Size: 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. *** Available for: Ultra-clear glass,K9,BK7,B270,D2637T, Quartz Glass(Fused Silica) or other specified material. | |
Spectral measurement graph
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Picture 1: LP780nm Spectral measurement graph |
What is a 780nm Longpass Filter and its typical application?
A 780nm longpass filter is an optical filter component that selectively transmits near-infrared light with wavelengths longer than 780nm, while effectively blocking shorter wavelengths below 780nm. 780nm longpass filters are widely used in Raman spectroscopy, fluorescence microscopy, industrial imaging, and IPL devices. Their core function is to separate visible light from near-infrared, improving detection accuracy and treatment safety across these fields.
What is key parameter when choose for right Longpass Filter?
When selecting a Longpass Filter, normally the following factors need to be taken into consideration：
- Cut-Off Wavelength: it is one of the most important parameters, typically defined as the wavelength transmittance at 50% .
- Average or Peak transmittance: usually average transmittance ≥90%, higher transmittance e.g. 92% or 95% on average or specific single point need to definite and communicate with manufacturer, higher transmittance need to additional AR coating.
- Blocking rate: usually expressed 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 consider 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.
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.
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.
