Filter is an optical element that can selectively transmit or block light of a specific wavelength. Its core function is to achieve precise regulation of parameters such as wavelength and intensity of light through material characteristics or physical structure. The following is the classification description of its main functions and application scenarios:

1. Basic Function

Spectrum Selection

Filters interfering light (such as infrared, ultraviolet), retains light in the target band, and improves the system signal to noise ratio. For example, in a camera, IR-Cut filters can block infrared light above 700nm and avoid color distortion.

is used to obtain monochromatic light in double-slit interference experiments.

Enhances Contrast

makes specific colors or objects more vivid by filtering light in non-target bands. For example, a red filter only transmits red light, which can highlight the color of safflower.