400 nm Narrow Bandpass Optical Filter

The 400 nm narrow bandpass optical filter is an ultraviolet narrow bandpass filter manufactured using a highperformance, multilayer hard dielectric thinfilm coating process. It is specifically designed for efficient transmission of optical signals at the 400 nm band and suppression of outofband light. The filter achieves an average transmittance greater than 90% over the operating band of 394–406 nm, while providing excellent blocking performance across the ultraviolet, visible, and nearinfrared nonoperating regions. This effectively reduces stray light interference, improving detection sensitivity and imaging quality. The product offers good environmental stability, high laser damage tolerance, and excellent spectral consistency, making it widely applicable in highprecision optical systems such as ultraviolet laser systems, fluorescence detection, biomedical analysis, spectroscopic instruments, machine vision, and scientific research.