To describe these properties, it is useful to think of light as a wave. In the visible spectrum for example, red light has a large wavelength and a low frequency while violet light has a short wavelength and high frequency. This pattern is characteristic of the object being holographed. A laser provides such a light source.
Diffraction describes the ability of a wave to spread out when it meets an obstacle.
When light waves meet the hologram's interference pattern , they spread out such that a perfect replica of the original object's wavefront is created. It is as if we were looking through a window in which the real object can be seen. Some can be viewed only with laser light while others, called rainbow holograms, can be viewed with white light . The holograms of objects on exhibit in LightForest are white light copies of master transmission holograms.