1.Product Descriptions:
| Characteristics: | 708nm Bandpass Filter |
| Type: | Interference type |
| Central Wavelength (CWL): | 708nm |
| Full Width at Half Maximum(FWHM): | 40nm |
| Peak Transmittance(%) : | >92% |
| Cut-off depth: | OD2-OD3 |
| Shape: | customized |
| Color: | Dark red |
| Surface Quality: | 60/40 |
| Dimension(mm): | Customized * |
| Thickness(mm): | 0.21-3mm |
| Substrate: | Optical Glass** |
Remark: Spectral range:350-1100nm *Common for 86x86mm, 80x80mm, other can customized, max. 300x300mm **Available for ultra-clear glass,K9,BK7,B270,D2637T, Quartz Glass(Fused Silica) or other specified materials. | |
2.Measured Spectral Graph – 708nm Bandpass filter:
 |
| Picture 1: BP708-40nm Graph measurement |
3.What is typical application for 708nm Bandpass Filters?
A 708nm bandpass filter is an optical component engineered to transmit light centered at 708nm while blocking all other wavelengths. Typically, applications for 708nm bandpass filters focus on isolating near-infrared fluorescence signals, particularly in flow cytometry and fluorescence imaging for detecting dyes, enabling multi-color analysis with reduced spectral overlap. They are also essential in pulse oximetry and tissue oxygenation monitoring, where deep-red light penetrates biological tissue effectively, as well as in laser line cleanup, machine vision, and remote sensing.
4.What are key parameters when choose for a suitable Bandpass Filters?
When selecting a Narrow Bandpass Filter, normally the following factors need to be taken into consideration：
- Central Wavelength (CWL)：CWL is one of key parameter to designate first, it refer to the central wavelength at stable high transmission rate passband.
- Peak or Average Transmittance: typically ≥90%, Higher transmittance might need Anti-reflective(AR) coating.
- Full width at half maximum (FWHM): FWHM refer to the interval between the two wavelength points where the transmittance rate reaches 50%.
- Blocking rate: usually 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 considered 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 coating 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 typical Bandpass filters in stock from Liyuan Optoelectronics include BP810 BP820 BP830 BP840 BP850 BP860 BP870 BP880 BP890 BP…etc.
