1. Machine vision. The light source illuminates the workpiece, and the light reflected from the workpiece carries image information; the filter only allows the target feature wavelength to pass, blocking other wavelength ambient light and stray light; as the core optical component for spectral selection, the performance of the filter directly determines the image signal-to-noise ratio, contrast, interference suppression, and imaging accuracy, and it is a key component for improving the stability of visual inspection at low cost.

2. Laser sensing and laser ranging (LiDAR, laser displacement sensors, laser barriers). Industrial laser radar, laser displacement thickness/height measurement, laser ranging sensors, laser safety light curtains, laser barcode scanners. Commonly used filters: laser narrowband filters (bandwidth typically 10~30nm).

3. Infrared Temperature Measurement / Infrared Thermal Imaging (power, metallurgy, furnaces, equipment inspection). Working principle: Any object above absolute zero emits infrared thermal radiation; the object's radiation spectrum and temperature follow Planck’s blackbody radiation law. The infrared detector receives the infrared radiation, and the filter selects the temperature measurement wavelength band of the target, filtering out unwanted band radiation and visible light.

4. Spectral analysis type industrial testing (online water quality monitoring, oil and gas, flue gas analysis, thin film thickness measurement).