What is the principle of a circularly polarized light detection card? How to use it?

A: The circularly polarized light detection card is essentially a polarizing film (polarizing film), which uses the characteristics of polarized light to verify the polarization pattern of light. Usage method: ① Place the test card in front of the illuminated screen; ② Slowly rotate the detection card; ③ Observe the changes in the screen image: If it is circularly polarized light, during the rotation process, the brightness and color of the image remain uniform and soft, with no obvious changes in light and dark. If it is linearly polarized light, when rotated to a specific Angle, the picture will become significantly darker or even darker, and there may be uneven brightness or abnormal local colors. Principle: When linearly polarized light passes through a polarizer, its transmittance varies with the Angle of the polarizer (Malus' law), being the brightest at 0° and the dimmest at 90°. Circularly polarized light has uniform components in all directions, and the brightness remains unchanged when the polarizer is rotated. Woowhead Guanfudun comes with a circularly polarized light detection card in the box. Users can personally verify whether the screen light after applying the film is circularly polarized light, transforming the invisible optical technology into verifiable facts.