What are the characteristics of holograms?

Holographic photos are different from ordinary photos. Under proper illumination, the scene displayed on the hologram is three-dimensional, and all sides of the scene can be seen.

Holography is different from traditional photography. Conventional photography only records the change of light intensity on the surface of the object being photographed, that is, only records the amplitude of light. Holography records all the information of light waves, not only the amplitude, but also the phase of light waves. In this way, all the information of the optical wave field of the space object is stored and recorded. Then, the original space scene is displayed by using the diffraction of appropriate illumination light by holographic photos. It can "resurrect" a frozen scene before people. This unique property of hologram makes it widely used, such as studying the shock wave of rocket flight and nondestructive testing of wing honeycomb structure.

At present, holographic three-dimensional display is developing towards holographic color stereoscopic TV and movies. The method of holography has also expanded from the optical field to other fields. Such as microwave holography and acoustic holography, have made great progress and have been successfully applied to industry and medical treatment. Holographic technology of electron wave, seismic wave and X-ray is also under in-depth study.