All existing commercial holographic technologies are in fact optical illusions. These are either two-dimensional models that need to be looked at at a certain angle, or templates for use in a set with glasses of augmented reality like HoloLens. True holograms, where light forms a three-dimensional picture, are now tiny and unsightly.
One of the reasons for this state of things is that when you move from a two-dimensional picture to a three-dimensional image, the amount of data to write this information grows to indecently high values. Processing such a digital array is an extremely time-consuming undertaking, so a hologram measuring 1 cubic centimeter with a maximum viewing angle of only 3 degrees is considered a very worthy result. To create something more elementary is unprofitable.
While supercomputers are not yet in their pocket, scientists from the Korea Institute of Advanced Technology (KAIST) have proposed an intermediate version. They arranged a pair of holographic diffusers between the light wave modulator and the viewer. These devices scatter light and create a kind of reflection, a copy of the original holographic image. It is full of noise and does not differ in detail, but it is much larger than the original, plus the viewing angle of the object increases.
In the experimental setup, Koreans obtained a truly three-dimensional hologram of 2 cm in diameter, which can be observed at an angle of up to 35 degrees. By the combination of parameters, this is 2.6 thousand times more effective than the work of existing holographic displays without diffusers. Control of scattered light turns it from an annoying hindrance to a useful ally, and in the future this will allow creating three-dimensional screens of large sizes. Convenient already for real work, and not just for laboratory experiments.
image courtesy techcult.ru