Scientists from different Japanese Universities and Sony CSL (check out the details in the description of the following video) are able to create real holograms. The amazing thing is that you are also able to interact with the hologram directly. The system is still small scale (1cm^3) however the size is scalable using better, larger optics and a bigger setup.
Using a high intensity laser, they excite physical matter to emit light in any 3D position. The trick is to induce plasma in air or volume using lasers. Let’s see how this technology evolve. Kudos to the Scientist Team and good luck at Siggraph 2015!