1.Product Descriptions:
| Characteristics: | 900-1800nm Longpass filters |
| Type: | Interference filter |
| Central Wavelength (CWL): | 900-1800nm or specified |
| Peak Transmittance: | >90% |
| Cut-off depth: | OD2-OD3 |
| Surface Quality: | 60/40 scratch-dig |
| Color: | Silver |
| Shape: | Square or specified |
| Dimension: | 38.2*20mm or specified |
| Thickness: | 1.0mm or specified |
| Substrate: | Ultra-clear glass,K9,BK7,B270,D2637T, Quartz Glass(Fused Silica) or other specified |
| Remark：
*Customized capability: 380-2500nm, stock for 10nm intervals.**Common for 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. |
2. Measured Spectral curve
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Picture 1: LP900-1800nm Longpass Filter Spectral Curve |
3.What is typical application for 900-1800nm longpass filter?
A 900-1800nm longpass filter blocks all light wavelengths below 900 nm and selectively transmits near-infrared light ranging from 900nm to 1800nm, effectively isolating NIR signals while suppressing visible light, ultraviolet rays and short-wave interference for reliable infrared optical system operation. 900-1800nm longpass filters have diverse applications across multiple sectors. To begin with, in medical aesthetics, they enable skin rejuvenation treatments by transmitting therapeutic near-infrared wavelengths. In the field of research, they facilitate NIR spectroscopy by extracting target signals and effectively blocking interference. Moving to fiber optics, these filters separate or combine O- to L-band signals for reliable communication. Finally, in surveillance, they enhance NIR imaging clarity by improving contrast in specific wavelength bands.
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.
