Circular interference-coated short-pass filter

hort-pass interference filter is an optical component designed based on the principle of light interference. It achieves high transmittance for short-wavelength light and high reflectance for long-wavelength light through a multi-layer film system with alternating high-refractive-index and low-refractive-index medium thin films. Its core function is to enable constructive interference of short-wave light between the film layers for transmission, while causing destructive interference of long-wave light for reflection or absorption. This effectively separates short-wave and long-wave signals, commonly used in spectral analysis, fluorescence detection, optical imaging, and other fields, featuring high transmittance, steep cutoff characteristics, and good wavelength selectivity.