The 808nm narrow-bandpass filter is an optical component designed for high-precision selection of light at the 808nm wavelength. Its core function is to allow light within the range of 808nm ± full width at half maximum (FWHM) to pass through while blocking light of other wavelengths. Structurally, it typically uses glass or quartz as the substrate, forming a Fabry-Pérot interference structure through multilayer interference coating technology (such as alternately depositing high/low refractive index materials like TiO? and SiO?), thereby achieving selective transmission of specific wavelengths.

Key Technical Parameters

• Center Wavelength (CWL): Precisely aligned to 808nm, determining the core functionality of the filter.
• Full Width at Half Maximum (FWHM): Typically less than 50nm (some products can be controlled within 20nm), ensuring spectral selectivity accuracy, suitable for high-demand scenarios such as laser systems.
• Blocking Depth: Expressed in optical density (OD value), generally requiring OD ≥ 4 (transmittance below 0.01%), effectively blocking interference from non-target wavelengths.
• Damage Threshold: Must match the laser power; fused quartz substrates are often selected for high-power scenarios to enhance tolerance.

Application Scenarios of 808nm Narrow-Bandpass Filters

Industrial and Laser Technology

• Laser Systems: Used for wavelength purification in 808nm semiconductor lasers, ensuring monochromaticity and stability of laser output, commonly found in fields such as laser communication and laser processing.
• Infrared Equipment: Serves as a key component in infrared sensors, reducing ambient light interference and improving low-light detection accuracy.