Product Descriptions :
| Characteristics: | 440nm Longpass Filter |
| Type: | Interference type Filter |
| Cut-off Wavelength (in nm): | 440nm ±7nm |
| Peak Transmittance(%) : | >90% |
| Optical Density (OD): | OD2-OD3 |
| Shape: | Round, Square or customized |
| Color: | Transparent. |
| Surface Quality: | 60/40 scratch-dig |
| Dimension(mm): | common for 86x86mm, 80x80mm, other can customized, max. 300x300mm |
| Thickness(mm): | available: 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:380-1100nm. | |
Measured Spectral curve
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Picture 1: LP440nm Spectral measurement Graph |
What is typical application for 440nm Longpass Filter?
A 440nm longpass filter is an optical component that transmits light with wavelengths longer than 440nm while blocking light with wavelengths shorter than 440nm. It is widely used in fluorescence microscopy, Raman spectroscopy, forensic UV/blue light inspection, medical diagnostic devices, industrial machine vision, scientific photography, currency authentication, portable spectrometers and laser systems to filter interfering UV and violet stray light.
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.
Related products:
LP420, 420nm Longpass Filter, 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.
