1.Product Descriptions:
| Characteristics: | 420nm Longpass Filter |
| Type: | Interference type |
| Cut-off Wavelength(in mm): | 420nm ±5nm |
| Average Transmittance(%) : | >93% |
| Optical Density (OD): | OD2-OD3 |
| Shape: | Round, Square, or custom specified |
| Color: | Amber |
| Surface Quality: | 60/40 scratch-dig |
| Dimension(mm): | specified |
| Thickness(mm): | specified |
| Substrate: | Ultra-clear glass,K9,BK7,B270,D2637T, Quartz Glass(Fused Silica) or other specified |
| Remark： (1)Spectral range:350-1100nm (2) Size customized: 86x86mm, 80x80mm, other can customized, max. 300x300mm (3) Thickness available: 0.21、0.3、0.55、0.7、1.0、1.1、1.5、1.8、2.0、3.0mm, etc. | |
2.Measured Spectral curve
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Picture 1: LP420nm Spectral Curve |
3.What is typical application for 420nm Longpass Filter?
A 420nm longpass filter is an optical device that transmits light with wavelengths longer than 420nm while blocking light with wavelengths shorter than 420nm. The 420nm longpass filter is widely used in fluorescence microscopy to block UV/violet light below 420nm while transmitting visible and near-infrared light, in optical spectroscopy to eliminate short-wavelength UV interference for accurate detection, in machine vision and industrial imaging to reduce UV glare and improve clarity, and in environmental monitoring, biochemical analysis, and optical sensing equipment to filter out unwanted short-wave light and stabilize target optical signals.
4.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 technology that apply depositing nanomaterials 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. Liyuan optoelectronics have been focus on optical coating for more than 17 years and 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.
