SolidLight from Light Field Lab delivers true holographic video display
The holographic video dream has long been a sci-fi staple – the image of Princess Leia beamed from R2-D2 in Star wars, the holodeck in Star Trek: The Next Generation, and the shark that appears at Marty McFly in Back to the future II are just three examples. Well, this fantasy is now about to come true, but without breaking the laws of physics. A Silicon Valley startup called Light Field Lab developed the world’s first truly holographic digital signage technology, which I had the privilege of seeing for myself during a visit to the company’s offices this past. week.
Before I tell you what it is, let me tell you what it is is not. This is not the technology used to resuscitate Tupac Shakur on the stage at the concert at Coachella in 2012; it’s a 160 year old effect called Pepper’s Ghost that literally uses smoke and mirrors to reflect 2D floating images. And it’s certainly not autostereoscopic 3D, which companies like Samsung, Sony, Looking Glass, and Stream TV have demonstrated for years. This technology presents separate 2D images for each eye, as long as you’re in the right place, and sometimes causes dizziness and nausea due to what’s called vergence-accommodation conflict, which can also affect stereoscopic images based on glasses and headsets. .
Founded in 2017, Light Field Lab has developed a technology it calls SolidLight, which exactly mimics the behavior of light in the real world. When you look at an object in the real world, light from the sun or other source is reflected off the object at many different points in many different directions, some of which enter your eyes (see Fig. 1a). As you move around the object, different light rays or, more accurately, wave fronts enter your eyes and you see different perspectives. In addition, objects behind are masked (occluded) differently.
If you could generate all of these light wavefronts radiating in many different directions from many different places with no physical object, you would create a true holographic recreation of that object (see Fig. 1b). This is exactly what SolidLight does. Conventional stereoscopic images cannot do this: all the light comes from a single plane. Even though each eye is shown with a slightly displaced 2D perspective, these are images, not objects – not a true hologram by any means.
Problems that Light Field Lab solved include scale, density, and computation. To effectively form a true holographic object, you must generate and control the direction and amplitude of tens or hundreds of billions of wavefronts, which correspond to pixels on a 2D display. Keep in mind that a 4K display has 8.3 million pixels, while a state-of-the-art 8K display has 33 million pixels; compare that with the 10 billion pixels per square meter generated by SolidLight!
It is important to understand that all wavefronts in a scene are present at the same time and that your eyes can focus on any point on the scene at any time, just like in real life. Areas you are not focusing on have retinal blurring, just like in real life. All the attributes of light in the real world – reflection, refraction, diffraction, etc. – are faithfully reproduced. And more importantly, no special scopes, head tracking or other accessories are required.
How does Light Field Lab do? With a technology that has already generated more than 300 patent filings. The hardware is a SolidLight Surface modular video wall with three basic components. The first layer is a silicon-based phased array of electroluminescent devices in what the company calls a “polymer of nanoparticles.” Company representatives would not say exactly what these devices are; apparently they’re not LEDs, and they’re packed with a much higher density than even a microLED panel. This layer also includes all the electronics that provide significant processing power.
The intermediate layer is an amplitude modulated plane which, as its name suggests, modulates the amplitude of the light wavefronts of the photonic network under the control of electronics. Like the photonic lattice, the light modulator array consists of individually controllable submicron nanoparticles. This layer conditions the wave fronts of the final layer; if you were to look at the light emitted from the amplitude modulated plane it would be just a bunch of noise.
Finally, the PhaseGuide modulation plane is a static optical layer designed in coordination with the other layers to focus the projected objects. The precise optical properties of these components can be configured by the customer. For example, does he want objects to be two feet in front of the screen, behind the screen, or elsewhere?
The basic building block is a bezel-less submodule measuring over 6 x 4 inches with a resolution of 16,000 x 10,000 pixels, or 160 million pixels by approximately 27 square inches! Fifteen submodules are merged to form a square modular panel measuring about half a meter across with a staggering 2.5 billion pixels, which translates to 10 billion pixels per square meter. Multiple panels are then tiled to create a SolidLIght Surface video wall of any size, just like any other modular LED video wall system. According to the company, the precise placement of the electroluminescent elements is no problem, as is the case in microLED displays; alignment and calibration are performed in software.
Just about any 3D scene data from CGI systems such as Unity, Unreal, Maya, Blender or anything else that contains depth information can be rendered by SolidLight’s WaveTracer software in real time without needing to be ” pre-cooked ”. The encoded and vectorized photonic signal is analogous to a vectorized Dolby Atmos spatial-audio signal. The system can even synthesize depth information into 2D images.
In common video terms, SolidLight can display 10-bit WCG (wide color gamut) at 60 frames per second. It can operate at higher frame rates if this is to be a priority for Light Field Lab customers in the future. It can also use slower speeds to induce motion blur for artistic effect.
The demo itself was most impressive. A 28 inch (diagonal) panel was mounted behind a bookcase and surrounded by physical plastic plants. A holographic chameleon, affectionately referred to as Chammie, slowly moved along a branch and changed color. I could walk past the reptile, and the hologram completely obscured the real world plants behind it, as if it were a real, solid object. (The plants behind Cammie were actually hidden to the side, and their image was ‘relayed’ in the demo area and combined with that of the chameleon. They couldn’t be where they physically appeared to be, as that would have blocked the light. panel.)
I was invited to reach out and ‘touch’ Cammie, but of course I couldn’t, as there was nothing physical there. Holding a magnifying glass near the object looked exactly like it would with a physical chameleon. At the sound of a buzzing fly, Cammie’s tongue popped out and one of the physical plants in front of her quivered in response thanks to a synchronized actuator – very smart!
The system has been configured to present objects in a volume 14 inches diagonal by 6 inches deep about two feet in front of the panel itself with a viewing angle of at least 100 degrees and a target viewing distance of d. ‘about three feet. These parameters are all balanced in a total “photon budget”; you can increase one by decreasing the others, or you can increase the total photon budget by adding more SolidLight Surface panels. Additionally, the object brightness has been calibrated to 100-200 nits for indoor applications, although it can be much brighter with increased voltage and reduced lifespan like any other emissive screen.
I also saw another demo that I can’t say much about due to an NDA (non-disclosure agreement). I can tell it was an interactive holographic object that responded to my movements in real time, which was truly amazing!
When can we buy one?
The first applications will likely be places of public entertainment such as museums, corporate video walls, and virtual broadcast / production facilities, which we could see in just one to three years. In fact, the company has already pre-sold its entire first production run. Then in the product development roadmap, there are the tabletop displays for product viewing and games. Then, a telepresence wall would allow distant colleagues to interact with the same holographic object. Finally, we may see consumer video walls for home installation in the not-so-distant future.
What about the cost? Light Field Lab Says It Is Competitive With Large High-End 8K MicroLED Video Walls; a large Sony Crystal LED wall will easily make you go back seven digits. Obviously, SolidLIght won’t be available to most consumers for quite a while, but institutional clients could lose that kind of money for something so extraordinary.
In fact, funding for such an ambitious project came from Comcast / NBCUniversal, Samsung, Verizon, Bosch and others, key players in display technology, manufacturing, communications, and retailers. media who obviously believe it’s the Next Big Thing. I look forward to seeing SolidLight technology deployed in a commercial location, and look forward to following its progress with great interest.