Nano-Magnetic Pixels
The display was made possible through custom-developed, three-dimensional magneto-optic spatial light modulators (3D-MOSLMs), which represent holograms using magnetic domains as sub-micron scale pixels. The display is composed of an array of these magnetic pixels on an amorphous TbFe film. Using a pixel size of 1 µm, as well as a pixel pitch of 1 µm, the team achieved a viewing angle of 30 degrees.
"The advantages of this approach are that the focused spot of a laser defines the pixel size, the MOSLM does not require special current or voltage drivelines and the switching speed is about 10 nsec/pixel; that is enough for real-time display,” said Hiroyuki Takagi, one of the researchers involved in creating the display. This means the MOSLM could be used to display 3D movies and other 3D media.
Getting Rid of 3D Glasses
Conventional 3D displays create the illusion of three dimensions by presenting slightly different two-dimensional images to each eye. An example familiar to moviegoers is the stereo display that makes use of polarized glasses to produce the 3D effects. However, this pseudo-3D technique can cause incongruity and eyestrain for viewers.
In contrast, holographic displays are able to exactly reproduce the light waves scattered from a 3D object. This allows the user to view a realistic 3D image with smooth motion parallax, without the need for special glasses. However, the viewing angles for holographic displays are conventionally less than 3 degrees.
With this latest breakthrough allowing for a tenfold increase in viewing angle, holographic displays may soon become an appealing option for 3D displays.
For more information, check out the research report published in Applied Physics Letters.