The Japanese company Burton Inc. has managed to create holograms which can be touched. In order to make this work they used femtosecond lasers. The research team called the holograms Fairy Lights.
To produce these incredible holograms the researchers modified high-speed lasers. The lasers usually used in this type of inventions function with a nanosecond cycle which means one billion of a second. This way the lasers can cause a burning sensation when you touch the beam so they cannot be used for interactive displays. So what the researchers did was to speed up the lasers to a femtosecond cycle, which is a million times above the normal. As a consequence the safety and practicability was increased and the holograms are safe to touch.
So basically he faster the laser is the safer it is for humans to touch it. Slow lasers can burn you, whereas femtosecond lasers fire so quickly that there are fewer chances for you to get any injury. However you can still feel the lasers. When you touch the plasma voxels shock waves are generated so you will feel an impulse on the finger giving you the impression that the light is material.
The feelings produced by the pressure on the skin are indeed haptic sensations. This gives the image a real world feel much like the sensation we associate with touching materials such as cloths or wood. Moreover the researchers explained that this system does not need suspended materials in the air in order to function like the 3D version of a movie screen and they can also be controlled to a fine degree.
Although it sounds very exciting this femtosecond lasers technology will not be available too soon in living room television. The images produced so far have the size of about 1/2000th of a cubic inch. Only with further development will this technology be available in larger versions.
If this will be put into practice the technology will be used for a wide range of purposes both on Earth and in space. For example the lasers can be used to create a whole new range of AR devices (augmented reality). Moreover scientists could create interfaces which will seem to float in mid-air. This could be used when providing real-time instructions for various purposes.
Image Source: Mashable