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.
2. Measured Spectral curve
Picture 1: LP680nm Spectral measurement Curve
3.What is typical application for 680nm longpass filter?
A 680nm longpass filter allows red and near-infrared light with wavelengths greater than 680nm to pass through, while blocking visible light with wavelengths shorter than 680nm. 680nm longpass filters enable thermal imaging by blocking visible light and transmitting long-wave infrared. In medical aesthetic devices like skin rejuvenation and hair removal systems, they filter harmful short-wave light while passing red and near-infrared. In fluorescence microscopy and Raman spectroscopy, they block excitation light to enhance signal-to-noise ratios. They also support security systems, facial recognition, stage lighting, fiber optics, and infrared photography by eliminating stray light or modulating light effects.
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 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. 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 & Short Filters, Notch Filters, ND filters, Star filters and Optical sapphire block.
other Longpass filters in stock from Liyuan Optoelectronics: LP430 LP500 LP560 LP600 LP650 LP800, etc.
