Product Descriptions:
| Characteristics: | 900nm Longpass Filter, AR coating |
| Type: | Interference filter |
| Cut-off Wavelength(CWL): | 900nm ±5nm |
| Average Transmittance(%) : | >95% |
| 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 customized: 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: LP900nm +AR Spectral measurement Curve |
What is typical application for 900nm Longpass Filter with AR coating?
A 900nm longpass filter with AR coating is an optical component that efficiently transmits near-infrared light with wavelengths longer than 900nm, while blocking visible light and a portion of the near-infrared spectrum below 900nm. The AR coating serves to minimize surface reflections and maximize transmission efficiency.
The 900nm NIR longpass filters with AR coating find a wide range of applications, including near-infrared spectroscopy, fluorescence microscopy, LIDAR and range finding, medical aesthetic IPL devices, machine vision, and fiber optic communications.
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.
