The 275nm filter is a narrow-band interference filter specifically designed for UV-C LEDs and low-pressure mercury lamps. It features a center wavelength of 275nm ± 2nm, a full width at half maximum (FWHM) of 10-12nm, a peak transmittance of >25%, and an OD6@275±20nm. It efficiently extracts the germicidal wavelength range while completely blocking visible and near-infrared stray light. The substrate is made of deep-ultraviolet-grade fused silica, coated on both sides with a hard dielectric film of LaF?/MgF?. It withstands 1J/cm2 pulsed laser exposure, has a surface roughness of <0.3nm, and is packaged in a Class 1000 clean environment. Suitable for applications such as air/water sterilization, surface disinfection, fluorescence detection, and biochemical analysis, it operates stably within a temperature range of -40 to +150°C and serves as a core optical component in epidemic-prevention-grade ultraviolet systems.