The disorderly flowers are fascinating. What is the holographic?

Wensingdo drooling, monkey king eight -claw burning

From the definition of "holographic" in this issue, we analyze the existing technologies on the market in multi -angle to see which ones are flower fist embroidered legs and which are true and talented. (The following is the author's point of view, welcome professionals to correct)

First of all, Hologram is a synthetic word, derived from Greek: Holos (all)+gramma (information), as the name suggests, it is a technology that records and reproduces all optical information of the object. So, what does optical information include? We all know that light can be regarded as a wave, so information such as the amplitude, wavelength, and phase of the waves are all collection objects of "holographic".

The biggest difference between holographic image and ordinary image in visual perception is the so -called "three -dimensional sense", and the key factor to create a "three -dimensional sense" is the phase information carried by light. Our eyes can see that objects are due to its own light or reflection. These lights are like data cables connected to the eyes to transmit various optical information of the object to our eyes to recognize the object.

Similar to human eye working methods, the ordinary image recording method receives the amplitude (influence, darkness, contour) and wavelength (determining color) information of objects, and use a certain means to be restored. The method uses the interference stripes generated by the two beams of laser to enter the phase information into the film and re -illuminate the laser again to the film, which can "reinstate" all optical information to form images with a three -dimensional perception.

The most basic holographic photography work process: a laser is divided into two beams from the light device, one beam is shot on the photographed object, and then reflected on the film. At this time, it is not just a beam of light, but the objects are tens of millions Wanxian's reflective light, we call it "object light"; the other bouquet directly illuminates the film, we call it "reference light", "object light" and "reference light" are superimposed and reduced to each other, that is, it occurs. The phenomenon of interference is exposed for a certain period of time on the film, forming interference stripes and recorded on the film.

The intervals and contrast between the interference stripes are actually the "encoding" of the optical information of each point of the object. These stripes are very small. Only a microscope can be observed, and the film looks transparent. , "Reference Light" and the interference stripes on the film are diffracted, which is equivalent to all points of "object light" and "Reference Light" met again in the film, restore the state of taking pictures at the time, and all the "object light" on the object on the object. "Summon" again, "reorganizing" objects, thereby "decoding" stereo images.

Use the related light interference effect to create a holographic diagram. Divide the light from the split mirror into two beams: beating on the object and reference light. Common role to form interference patterns that can be recorded by film. Laser in the laboratory is an ideal light source that can satisfy coherent. Two independent ordinary light sources cannot form coherent light, so interference stripes cannot be formed. Source: wikipedia

The process of rebuilding the three -dimensional image. Source: wikipedia

Take a cup that does not exist but can be imagined in life, and quickly freeze a cup, and countless water molecules are condensed into frost on its surface. Suppose these water molecules can be fixed in any state. The moisture molecules become atmospheric, and the cup thaws and removes. At this moment, the temperature is dropped quickly back to the beginning of the frozen state. The water molecules are condensed into frost again, and the shape of the object is reproduced. The water molecules here are equivalent to the "object light" light spots formed by interference. The air is a film, and the controllable temperature is equivalent to "reference light". With the reduction of the temperature, the "image" of the cup is also restored.

The holographic image is still a little magical. Even if the holographic photo is cut, each fragment also contains all the optical information of the object. Through these fragments, it is like watching the world through the telescope. Different parts. Ordinary photos cannot be done. This is due to the special recording method of holographic, which enables each of them to include all optical information of the recorded objects.

You can also see all information through the fragments of holographic photos. Source: YouTube

So, is the "holographic naked eye 3D experience" overwhelming in our lives? Is it a real holographic? Is the three -dimensional image projected by the robot in "Star Wars" and the cool suspended operation interface of "Iron Man" look like a future holographic?

The author believes that in fact, the record and restore technology of static holographic images have been relatively mature, and dynamic holographic images in the strict sense need to be separated from the display medium, directly forming a 360 -degree -free viewing image in the air, and it has not come out. The concept and theory of holographic and theory were initially proposed by British Hungarian scientist Gábor Dénes in the 1940s that it should be realized in the 1960s. Essence

Nowadays, the holographic technology and three -dimensional image technology are not rigorous in the market. The holographic can actually be regarded as a way to achieve three -dimensional images and three -dimensional perception, which is relatively parallel to other technologies. At present, only the holographic technology can record and restore the phase information. The "physical" attribute is very prominent. It is necessary to distinguish between the common authentic holographic in the market. It is not real holographic.

Holographic image in science fiction movies. Source: YouTube holographic art work. Source: YouTube

Next, we introduce several technical methods that often confuse the concept of "holographic" on the market, but can realize a three -dimensional perception.

We attribute the following technologies as "pseudo -holographic", and we often call ourselves "holographic" on the market. Note that "pseudo" is not a derogatory term. Most of these technologies have good visual effects, less limited, wide application scenarios, and high degree of commercialization. They are only largely deviated with the original concept of "holographic". Maybe you can jump out of the holographic definition box and self -reliance.

Mirror reflex visual illusion

3D Illusion Maker. Source: YouTube

This product like a flying saucer is a mirror inside. When the toy frog is placed to the bottom, watching a specific angle at the open hole, you will feel that the frog is lying on the small hole, as if it can be within reach, but it stretches for "bamboo bamboo, but the bamboo but" bamboo bamboo but "bamboo bamboo but" bamboo bamboo but "bamboo bamboo "Basketball is empty", which is hot. This "prank" has a very real three -dimensional three -dimensional effect, which actually uses the principle of reflecting imaging of the concave mirror.

The light of the physical frog passed through various mirror reflexes of the concave mirrors in two plates, and a reverse image was formed at the small hole. The observer saw the virtual image from the perspective of the reflection light focus, and saw the "suspended" frog.

The magician and the setting master have created a lot of classic and interesting gameplay for this visual mystery effect achieved by mirror reflection.

Mirror reflection device art. Source: wiki

Using visual illusion can also achieve a more magical three -dimensional effect. Imagine that a boundless screen is placed in front of the whole black background. No one will think that the pipe is floating in the actual space, because there is this screen in front of the eyes, then if the screen is like a piece of one piece Glass, only a suspended smoke bucket is displayed. Through the background, it is like looking at the scenery through clean and indifferent glass. We will produce an illusion of this pipe is the illusion of hanging in our space. The three -dimensional sense is extremely strong. This is the basic disk of most of the "holographic" technology on the market. In fact, our eyes have been "cheated".

There are many ways to implement this "pseudo -holographic" technology. Use methods such as vision, projection, digital technology and other methods to presented the image on a certain transparency medium. Because the imaging medium is as invisible, the "image" seems to be "alive" in the "alive" in the "alive" in In real space.

3D fan screen

LED fan screen. Source: YouTube

The 3D fan screen uses the phenomenon of visual retention. The fan blades are equipped with CNC LED lamp array. When rotating at high speed, the displayed screen forms continuous dynamic effects. Fan blades with imaging medium are "hidden", and can only see the prospect image, giving a three -dimensional illusion of floating in the real space. Of course, this imaging method cannot be observed from the side and back.

Perper Phantom

Pepper Speeds Ghost's technology is widely used, relatively mature, and has a long history. It was originally designed for stage magic performances. Now it is mostly used in playgrounds, ghost houses, stage performances and other fields. Jay Chou and Teresa Teng's singing, Madonna's cross -dimensional stage with the virtual band, the stunning "shadow body" of Burberry showed this technology.

Teresa Teng sang with Jay Chou on the same stage. Source: wiki

Putting the "semi -transparent and half -anti" film on the stage with the floor with 45 ° tilt. The image of the black background (such as actor performance images, special visual effects, etc.) is played over the ground on the ground. The vertical angle appears. By controlling indoor lights, the audience cannot see the film and black background as a image medium from the front. The actors in the "image" also performed on the stage floor.

The film is placed on the stage with 45 ° on the stage. Source: YouTube

Peppers Ghost needs to be watched at a specific angle. Generally, it is in front of the stage.

There is a rich "360 -degree holographic" DIY tutorial on the Internet. Placing pyramid -shaped transparent plastic boards on the mobile phone screen, corresponding to each transparent plastic board, video of the black background, through the pyramid, watch from the front, you can watch it, you can watch it, you can watch it. To the three -dimensional image.

The following technologies we think can be classified as "holographic". Compared with "pseudo -holographic", its technical threshold is higher and closer to the concept of holographic. It also formed a three -dimensional three -dimensional image, but did not break away from the imaging media. Some need to wear equipment, some are limited by viewing angle, and some cannot show complex images temporarily.

Holographic

The optical information received by our left and right eyes reflects the images slightly different. The brain judges the distance between the information difference between the same object on the same object according to the left and right eyes, and then generate a three -dimensional sense of space. This is the concept of Parallax. Using visual dialogue and simulated eye habits to achieve some three -dimensional effects.

Nintendo's 3DS game console uses the principle of dialogue to show two images on the screen at the same time, so that players can feel the "naked eye 3D" effect.

Nintendo 3ds naked eye 3D effect. Source: YouTube

"Looking Glass" this product also uses the principle of dialogue, similar to the grating animation that we often see on the grid when we were young. From another perspective, different images will be seen. , Convert 2D images in real time into 50 images of different levels of observation angles, and then use a special multi -layer synthetic thick glass for lighting and filtering, which is equivalent to displaying different angles at each layer. Finally, the three -dimensional images that can be observed naked. This technology is currently known as the "light field holographic". Looking Glass product map. Source: YouTube

XR technology

Remember the "Mogito" performed by Jay Chou, 2021 Spring Festival Gala? In the live broadcast, Jay Chou danced in the three -dimensional animation space full of Cuban style and Memphis art. In fact, these pictures did not exist at the scene, but used the extension reality XR (Extended Reality) technology to use these virtual elements and performers and real spaces Synchronous synthesis, strict silk seams are presented in the screen. With the development and application of technologies such as augmented reality and hybrid reality, our real world and the virtual world complement each other. "Zhuang Zhou Mengdie" may become a common topic of all mankind.

Mogo performed by Jay Chou of the Spring Festival Gala. Source: cctv.com

XR uses digital computing technology, combines realistic scenarios and virtual environments, and realizes certain human -computer interaction; it includes augmented reality (AR), hybrid reality (MR), and virtual reality (VR). All three -dimensional images and effects need to be worn. Equipment or on the screen is presented, although the technological development of digital scanning, modeling, image, interaction and other technological development will make the appearance effects of various types of XR closer to the truth. There is a certain difference in essence. From the original concept, it should not belong to the traditional holographic.

Interactive air projection

Interactive Aerial Projection. Source: YouTube

Interactive Aerial Project is the same as the phenomenon of "mirages". It was originally a research and invention by Chad Dyne, a graduate student at Massachusetts University of Science and Technology. No need to wear additional devices, users can observe both three -dimensional images and can interact with gesture.

This projection system consists of a projector and "air screen". By discharging a large number of artificial fogs, combined with air power manufacturing relatively flat fog walls, the picture is projected on it. Due to the imbalance of the molecular vibration of the air and the fog wall, it forms a three -dimensional 3D image. With gesture interaction, it looks like it is like The "flat replacement" of Iron Man holographic operation interface. (Perhaps the additional functions of hand moisturizing, indoor humidification, and aromatherapy)

Sound suspension imaging

Multimodal Acoustic Trap Display (MATD) is different from the above projection equipment. This display technology is different. Use Acoustic Levitation to make a 2mm suspended particles in the suspension under the action of ultrasonic waves. High -speed exercise.

Matd. Source: YouTube

The upper and lower rows of micro speakers up and down to form a slender array to emit high -intensity sound waves. The continuous vibration of the sound waves causes the air molecules to continuously alternately relax and relax, resulting in the continuous ups and downs of the air pressure in the device. The force, and then use this force to control the precise movement of the ball, the sound waves are like an invisible hand, holding a small ball. According to the principle of visual retention, the high -speed movement of small balls in the three -dimensional space causes the eye to cause the visual image to lag, thereby continuously forming a 3D image visible to the naked eye.

大家一定看过无人机群表演，在空中组成各种富有立体感的形状，如果可以实现对于多个小球的精准位置及色彩控制，那么每一个小球就像一架无人机一样，成为A pixel point outlines a richer and more real three -dimensional dynamic "entity" image in the three -dimensional space.

Plasma imaging

Fairy Lights is also a non -projection 3D imaging technology. In addition to the three -dimensional vision, it even has a touch. Molecular ionization in the air into a hot pulp -like substance -electro -ion, and to form a short -term 3D image through the continuous laser explosion in the air. Injury. The author believes that the technology of "making lightning and forming graphics" is not as good as "Zeus".

Fairy Lights. Source Youtube

Although the above two technologies have made breakthroughs, the concept is full of imagination, but the cost is high. At present, there are many restrictions, and the imaging effect is single. It is also in the laboratory development stage. The possibility of short -term commercialization is not much. It may be the future development direction.

Introduced so many technologies, whether it is authenticity, pseudo -full interest, or holographic, whether it is flower fist embroidered legs, or real merit, is the result of "scientific knowledge+creativity". Essence The concept of "holographic" becomes more and more broad, and gradually integrates with other technologies. In some application scenarios, some technology that is classified as "pseudo -holographic" can even bring better visual effects. Science requires "rigorous", and life needs "relaxation". Perhaps, elegant and vulgar rewards, different, and selection of goodness and goodness are the flourishing and prosperous development. Perhaps the combination of some of these technologies has generated true full interest. Reference:

https://en.wikipedia.org/wiki/holography

https://en.wikipedia.org/wiki/curved_mirror

https://www.youtube.com/watch?v=tzwp-nl3LCK

https://www.youtube.com/watch?v=grvnsolz_vet=53s

https://www.youtube.com/watch?v=aowi10yvmfe

https://www.physicscentral.com/explore/Action/Femtosecond- Hologram.cfm

https://www.youtube.com/watch?v=tnctssbv1fi

https://www.youtube.com/watch?v=x2iyoyv_x0q

https://www.youtube.com/watch?v=tzn_qhtc-ni

https://www.twowaymirrs.com/peppers-gost- LLLUSION/

Reprinted content only represents the author's point of view

Does not represent the position of the Institute of Physics of the Chinese Academy of Sciences

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Source: AS Science and Art Research Center

Edit: Paarthurnax

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