MIT "Princess Leia" Holographic Display
MIT Researchers striked again! As explained in a Nature paper, they managed to build a cheap holographic display using a PC and some high-end graphic cards. Usually holograms are costly and of poor quality, but the new technology offers full-color, low-cost and can be used with any light source and not only high end lasers.
The new technology uses an array of "anisotropic leaky-mode couplers", acting as waveguides for light while allowing the light that is travelling through them to be manipulated. When exposed to radio-frequency radiation, the hardware will form acoustic waves that alter the light travelling through them. This allows each coupler to rapidly alter the timing and direction of the light it emits in response to changes in the radio waves. By placing a number of them in close proximity, it's possible to get the light they emit to interfere (creating a hologram) and then change this hologram simply by altering the radio frequencies.
The interesting part is that those magic couplers can be manufactured on the cheap: a standard size display will need 500 of them and their total cost may be under 50$, opening up possibilities of a small Princess Leia moving in color on your living room table for less than 500$ in the near future. However, you will need to update your ADSL Internet connection: the bitrate needed for holographic 3D is estimated at around 1500 Mbytes/second (MIT reference).
Abstract from the full paper
Every holographic video display is built on a spatial light modulator, which directs light by diffraction to form points in three-dimensional space. The modulators currently used for holographic video displays are challenging to use for several reasons: they have relatively low bandwidth, high cost, low diffraction angle, poor scalability, and the presence of quantization noise, unwanted diffractive orders and zero-order light. Here we present modulators for holographic video displays based on anisotropic leaky-mode couplers, which have the potential to address all of these challenges. These modulators can be fabricated simply, monolithically and at low cost. Additionally, these modulators are capable of new functionalities, such as wavelength division multiplexing for colour display. We demonstrate three enabling properties of particular interest—polarization rotation, enlarged angular diffraction, and frequency domain colour filtering—and suggest that this technology can be used as a platform for low-cost, high-performance holographic video displays. Goto to Nature to read the full paper (subscription fee may apply).
Note that the MIT pre-announced this display in 2009.