The basic principles of holography

The basic principle of holography is to use interference to record wavefront information, and then reproduce the 3D image through diffraction by illuminating the recording medium. 

Why is it called holography? It essentially means recording all the light information. Traditional cameras typically capture 2D images by recording the amplitude/intensity information of light. In contrast, holography records not only the amplitude information but also the phase information of light.

By illuminating the recording medium, the image of the recorded object can be diffracted. This image generally has “directionality,” meaning that the diffraction efficiency is higher in a specific direction (usually the direction designed during the recording process).