We see things because our eyes are sophisticated light detectors: they constantly capture the light rays bouncing off nearby objects so our brain can construct an ever-changing impression of the world around us. When our eyes see a three-dimensional image such as apple, Light reflects off the surface of the apple into two eyes and your brain merges their two pictures into a single stereoscopic (three-dimensional) image. If you move your head slightly, the rays of light reflected off the apple have to travel along slightly different paths to meet your eyes, and parts of the apple may now look lighter or darker or a different color.
Photography, as this became known, has revolutionized the way people see and engage with the world but no matter how realistic or artistic a photograph appears, there’s no question of it being real. A typical lens-based photograph encodes the brightness of each light wave — a photo can faithfully reproduce a scene’s colors, but it ultimately yields a flat image. All the light traveling from the apple comes from a single direction and enters a single lens before it hits the light-sensitive image sensor chip (the CCD or CMOS chip in a digital camera), so the camera can record only a two-dimensional pattern of light, dark, and color. In addition, we look at a photo and instantly see that the image is dead history: the light that captured the objects in a photograph vanished long ago and can never be recaptured. Holograms are also a bit like photographs that never die.
Hologram also looks real and three-dimensional and moves as you look around it, just like a real object. They’re sort of “photographic ghosts”: they look like three-dimensional photos that have somehow got trapped inside glass, plastic, or metal. When you tilt a credit-card hologram, you see an image of something like a bird moving “inside” the card.
That happens because of the unique way in which holograms are made. Photography measures how much light of different color hits the photographic film. However, light is also a wave, and is therefore characterized by the phase. Hologram encodes both the brightness and phase of each light wave. Phase specifies the position of a point within the wave cycle and correlates to depth of information, meaning that recording the phase of light scattered by an object can retrieve its full 3D shape, which cannot be obtained with a simple photograph. That combination delivers a truer depiction of a scene’s parallax and depth.
First developed in the mid-1900s, early holograms were recorded optically. You make a hologram by reflecting a laser beam off the object you want to capture. That required splitting a laser beam, with half the beam used to illuminate the subject and the other half used as a reference for the light waves’ phase. In fact, you split the laser beam into two separate halves by shining it through a half-mirror (a piece of glass coated with a thin layer of silver so half the laser light is reflected and half passes through—sometimes called a semi-silvered mirror).
One half of the beam bounces off a mirror, hits the object, and reflects onto the photographic plate inside which the hologram will be created. This is called the object beam. The other half of the beam bounces off another mirror and hits the same photographic plate. This is called the reference beam. This reference generates a hologram’s unique sense of depth. A hologram forms where the two beams meet up in the plate.
With the invention of intense coherent light sources (lasers) and their most recent technological advancements, optical holography has become a popular technique for three-dimensional (3D) imaging of macroscopic objects, security applications, and microscopic imaging. Due to its noninvasive and label-free properties, holography has been applied to biological imaging, air/water quality monitoring, and quantitative surface characterization measurement.
Holography is also used to detect stress in materials. A stressed material will deform, sometimes so minutely that it is not visible. A hologram can amplify this change since the light reflected off of the material will now be at a different angle than it was initially. A Comparison between the before and after holograms can determine where the greatest stress is. In Europe telephone credit cards use holograms to record the amount of remaining credit. Fighter pilots use holographic displays of their instruments so they can keep looking straight up. Museums keep archival records in holograms.
However, the resulting images were static, so they couldn’t capture motion. And they were hard copy only, making them difficult to reproduce and share. Computer-generated holography sidesteps these challenges by simulating the optical setup. But the process can be a computational slog. “Because each point in the scene has a different depth, you can’t apply the same operations for all of them,” says Shi. “That increases the complexity significantly.” Directing a clustered supercomputer to run these physics-based simulations could take seconds or minutes for a single holographic image. Plus, existing algorithms don’t model occlusion with photorealistic precision. So Shi’s team took a different approach: letting the computer teach physics to itself.
Holography is not only used to make three-dimensional pictures and it does not confine itself to the visible spectrum. Microwaves are used to detect objects through otherwise impenetrable barriers. X-rays and ultraviolet light are used to detect particles smaller than than visible light. This is how holography was discovered. Dr. Dennis Gabor is recognized as the inventor of holography when he used it to aid in his electron microscopy in 1947.
Holography also has military applications. Holograms and similar technologies offer the possibility of realistic, cost-effective training and education for a broad array of military missions and commercial applications. The military’s increased reliance on virtual reality to train warfighters may be converging with rapid advances in technology that will bring the holodeck of Star Trek fame closer to actuality. The U.S. military already has put virtual humans to good use. For example, the Institute for Creative Technologies (ICT) at the University of Southern California, Los Angeles, has used virtual reality characters to touch warfighters in one way or another before, during and after combat deployments
Dr. John Parmentola, Director of Research and Laboratory Management with the Army’s science and technology office is “making science fiction into reality” by creating realistic holographic images, generating virtual humans. They’re working on creating “photorealistic looking and acting human beings” that can think on their own, have emotions and talk in local slang. “I actually interact with virtual humans in terms of asking them questions and they’re responding,” Parmentola said.
Military requires holograms for battlefield intelligence, military planning and explosives disposal purposes. Situational awareness as some critical battlefield information would be better understood when viewed in three dimensions rather than two. The desire to enable the U.S. military to view such information via holograms is the driving force behind a number of research projects under way at some of the nation’s top universities and imaging companies. Military also interested in holography as a psychological warfare tool. The “Face of Allah” weapon would beam a massive, lifelike hologram over a battlefield, projecting the image of some deity “to incite fear in soldiers on a battlefield,” according to one researcher.
Maj. Gen. Jonathan Maddux, USA, program executive officer for simulation, training and instrumentation, indicates that hologram technology “continues to be a work in progress” but that Tactical Digital Hologram technology has “shown promise” with the U.S. Army Special Forces in Afghanistan and Iraq. Special operators use the technology to create 3-D maps of villages or specific buildings.
Military applications of Holographic projectors
Geographic intelligence is an essential part of military strategy and fully dimensional holographic images are being used to improve reconnaissance. One American company has delivered over 13,000 3D holographic maps of “battle-spaces” for the US army. This allows soldiers to view three-dimensional terrain, look “around” corners and helps with mission training. Zebra Imaging, of Austin, Texas, provides two-by-three-foot plastic holographic maps to the DOD. The military sends data to the company, and receives in return holographic displays of battlefields in Iraq and Afghanistan. The image is activated with a custom-made LED flashlight. Another use for Zebra’s holographic imaging technology is for post-blast roadside bomb forensics, according to the company’s Web site. By using a 3D hologram, analysts would be better able to understand the nature and construction of the device than if they had viewed it in 2D.
One 1999 Air Force Manual purportedly writes of the device thus: The holograph projector plays a three-dimensional visual image in a desired location, removed from a display generator. The projector can be used for psychological operations and strategic perception management. It is also useful for optical deception, and cloaking, providing a momentary distraction when engaging an unsophisticated adversary. And it has capabilities for precision projection of three-dimensional visual images into a selected area. Supports Psy-Op and strategic deception management and provides deception and cloaking against optical centers.
In Japan, for instance, there was a demonstration of such strange technology in 2006, in which Japan’s National Institute of Advanced Industrial Science and Technology (AIST) used lasers to project real three-dimensional images in mid-air. The device used lasers that were fired in rapid successive bursts to create various shapes over it, during which time the heat emitted from the equipment caused the air to expand and crackle with an effect like a series of tiny explosions, as well as creating an ozone-like smell.
In 2012, the country of China apparently unleashed a holographic image on a massive scale for the populace of the town of Guangzhou. It was here that an entire holographic city was allegedly beamed into the air, along with a UFO for good measure, which many people supposedly filmed. The problem with this theory is that the holographic technology that we know of at present is not able to achieve totally realistic images that could truly fool a person, is not able to display motion but rather only static images, and the images are not able to be projected particularly long distances or through obstacles, at least not yet, writes Brent Swancer in Holograms and the World of the Weird.
Holography breakthrough boosts accuracy of China’s artillery
Researchers at a university in North China’s Tianjin Municipality made a breakthrough in holography based on optical metasurfaces, with an expert saying the technology could improve the accuracy of military reconnaissance. A research team from the Center for Terahertz Waves of Tianjin University has greatly advanced holographic imaging technology and realized reflective chiral holography for the first time, Science and Technology Daily reported.
“Using the metasurfaces material and terahertz waves, the updated holographic plate could exhibit an image with essential features and very accurate status of location, which would greatly improve military reconnaissance,” Song Zhongping, a military expert, told the Global Times on Thursday. Holographic plates with metasurfaces could also record more data and better reproduce the images than ordinary plates, Song added.
A terahertz wave is a kind of electromagnetic wave, which has strong penetrability with good directionality. The waves are safe for humans. They are currently the least understood and least developed electromagnetic spectral band, according to the report. The metasurfaces plate can recognize different polarization states of light. This enables it to store more information and make fully independent holographic imaging, the newspaper reported.
“Such holography technology must pass various engineering tests under a battlefield environment to confirm its functioning before it is eventually adopted by the People’s Liberation Army (PLA),” Song noted. If fully developed, the technology would bring a sharp advance for artillery units of the PLA, allowing the units to achieve global leadership in artillery technology, Song said. The ability to convert a good idea into combat capability as soon as possible is important to the PLA, as it also would allow units to have a quick reaction in future battles, Song added.
Military One Step Closer To Battlefield Holograms
Optical scientist Nasser Peyghambarian and his teammates at the University of Arizona have demonstrated what The New York Times calls “actual moving holograms that are filmed in one spot and then projected and viewed in another spot.” The Times likens the holograms to the tiny image of Princess Leia that R2D2 showed Luke Skywalker in the beginning of Star Wars, only “a lot more haltingly, as the display changes only every two seconds.”
Peyghambarian’s hologram is created by a suite of 16 cameras that use lasers to record data on “smart” plastic some distance away that, when hit by a special light, project the image in solid-looking 3D. A partner team at Columbia University is studying ways to beam the holo-data via the Internet, to allow 3D video chats or instantaneous transmission of holographic maps, blueprints or medical scans. Peyghambarian said it might take a decade for the technology to become affordable and widespread. Weaponization would be much further behind (though we wouldn’t bet on today’s cash-strapped military to invest in a Face-of-Allah gun). Cost aside, it’s just not very PC.
Early holograms are already a fixture in military headquarters, according to the Times article. A company called Zebra Imaging in Texas has been selling 2-by-3-foot plastic holographic maps to the Pentagon – its “main customer” – for $1,000 to $3,000 a pop. The military “sends data in computer files to the company. Zebra then renders holographic displays of, for example, battlefields in Iraq and Afghanistan.” No goofy 3D glasses required, just a custom-made LED flashlight that “activates” the image encoded in the plastic.
Zebra’s technology has other military applications, such as post-blast IED forensics, according to the company’s Website. “Analysts trying to understand the nature and construction of an explosive device … are able to understand the scene in 3D far better than the classic 2D ‘bird’s-eye view.'”
Global Hologram Market
The holographic display market is expected to grow at a CAGR of 27.3% over the forecast period (2020 – 2025). The holographic display market may witness a sharp increase over the next few years, especially in developed nations such as the United States, with help from various industry players to augment the regional demand subject to the extensive product applications in automotive, healthcare research, and medical imaging.
While the healthcare, automotive, and media industries drive the demand for holographic displays, applications across media and entertainment, education, residential (living rooms), military mapping are expected to act as a catalyst for the market studied
Additionally, holographic displays are being used in digital signages, billboards, point-of-sale terminals, kiosks, at places, and in events. The awareness regarding the use of holographic displays across all these applications may also significantly drive market growth. For instance, the retail sector has been substantially adopting digital signage solutions, with the significant and upcoming businesses opting for advanced digital signages featuring AI and machine learning to gain the most out of consumer analytics.
Technological innovations have been a critical factor driving the new solutions being introduced in the market. In addition to this, in the United States, places like Las Vegas, are transitioning from traditional billboards. Three – dimensional, slightly hypnotic holograms may soon replace two -dimensional signs and ads. Several companies with this technology claim that 3 – D holograms may revolutionize the way businesses and brands talk to potential customers, as per Kino-mo.
Further, trend aiding the adoption of holograms in this sector is the growing field of proximity marketing, to connect and drive their customer base by aligning themselves to engage their customers with a more tailored approach. An early instance of this is ARHT partnering with the Canadian retail chain, Harry Rosen, to display a human hologram named “Vincent,” the retailer’s first-ever human hologram, with the ability to count, confirm, and analyze a crowd to gauge the level of interest and deliver the correct value proposition
However, the high cost of assembling holographic display devices are restraining market growth. The process involves manufacturing and fabrication of new technologies, which might prove cost-intensive for smaller companies. Furthermore, the pricing might seem expensive for consumers across underdeveloped nations, limiting the market’s growth therein.
Major 5 Players of the market are : MDH Hologram Ltd, Looking Glass Factory Inc., Provision Holding Inc.,Realview Imaging Ltd and RealFiction Holding AB
May 2020 – Looking Glass Factory announced that its display technology would support the UE4 plugin to enable the content creators to visualize designs using its holographic displays. The new feature is suitable to be used in a range of industries, like automotive, architecture, mapping/GIS, and medical imaging. Apr 2019 – RealView Imaging’s launched the HOLOSCOPE-i, which is the world’s first medical holographic system that provides realistic, spatially accurate 3D in-air holograms, and was used in a valve procedure in Toronto. Cardiologists and cardiac surgeons at Toronto General Hospital’s Peter Munk Cardiac Centre (PMCC) performed the first live medical procedure using real-time holographic imaging developed by the company.
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