Interesting holographic history

Anyone who has seen those prehistoric paintings in Shaweidong, France, will be deeply impressed by the subtle changes in light and shade, the freely used perspective and the elegant and smooth lines. The rhinoceros, lion and bear drawn by these primitive people with ochre 32,000 years ago, although eroded by years, can still bring great visual shock to people. However, not everyone is as lucky as Jean-Marin Shawei and his two friends: when they stumbled upon this cave at 1994 12 18, all the caves opened their doors for them, and all the paintings were unconditionally displayed under their simple searchlights. However, when this discovery was made public and studied and protected by the French government as one of the greatest archaeological and artistic discoveries of the year, the door of Xiaowei Cave was closed to the public. Even experts engaged in related research have to go through a complicated approval process to enter the cave, and they should be fully dressed and do enough protection to ensure that they can't touch the cave wall. Ordinary people have no chance to see the truth, so they can only imagine it out of thin air by looking at the plan in the magazine.

However, Yves Ghent and his brother Philip Ghent, who live in the suburban town of Bordeaux, an ancient wine town, may use their holograms to turn all this into history.

A century ago, when Samuel Morse, the inventor of the telegraph, first saw the photos taken by silver disc photography, he was surprised to find that such a realistic image should never be called a copy of nature, but a part of nature itself. To a well-informed person today, Morse's reaction is somewhat unexpected. In this era when digital cameras can fully display their charm, no one is afraid that the people in the photos will blink at themselves and see their thoughts, just like the people who saw the photos for the first time in St. Petersburg. However, when Jacqueline Belloni, a chemical physicist and film-sensitive expert at the University of Paris-Sud, showed the holographic photos of butterflies made by Yves Ghent at an academic conference, a physicist who happened to be a butterfly specimen collector was very puzzled and asked her why she showed the specimen box of this scale-winged insect when giving an academic report. The physicist refused to believe that it was just a hologram.

In fact, the indecision of physicists is understandable, although holography is not a new concept for most people. In order to improve the resolution of electron microscope, Gabor put forward the theory of holography in 1948, and began the research of holography. After 1960, laser appeared, which provided high brightness and high coherence light source for holography. Since then, holographic technology has entered a new stage. Various holographic methods have appeared one after another, constantly opening up new fields of holographic application. Gabor also won the 197 1 year Nobel Prize in Physics for his research on holography.

Whether holographic photography or the earliest silver disk photography, their mystery lies in the recording of light. All light has three properties, namely its intensity, color and direction. Early silver photography and black-and-white photographs can only record the changes of light and shade, while color photographs can also reflect their colors by recording the wavelength changes of light. Holography is the only photography that can capture three properties of light at the same time. Through laser technology, it can record the direction of light incident on the object, and then refract it to reproduce the real scene of the object in three-dimensional space realistically.

However, before the Ghent brothers' works came out, the so-called true reproduction was only theoretical. Perhaps it is because good holographic images are rare and difficult to generate, or because the scientific principle of holography is too profound. After half a century of invention, holography is still a mysterious technology.

When some media reported the achievements of Yves Ghent and his brothers, some people described them as "the only people who truly realized the function of holographic photography to reproduce nature", while others said that their works were "a part of nature" as Morse said. These comments may be exaggerated, because there are actually many other people in the world who are engaged in holographic research. The International Holographic Manufacturers Association is an organization that has gathered experts and enthusiasts from all over the world. However, Yves Ghent is undoubtedly the best among these experts. In the winter of 200 1 year, the Federation awarded Yves two most weighty awards, "the best holographic work of the year" and "the latest holographic technology", which is the best explanation. At an academic conference on holography held in Austria, when the Ghent brothers spoke and showed their works, "140 experienced holographic masters took a deep breath with admiration". Philip was not complacent when he recalled the scene. He said, "When people flocked to watch the holographic pictures we made, the whole room was empty." The experts present at that time were fascinated by the almost unreal picture. They couldn't help reaching out and touching the exquisite patterns on the puppet clothes wearing traditional Lao dance costumes. Others want to wipe off the biscuit crumbs hanging from the mouth of the little girl who is eating biscuits. Of course, all they met was a thin layer of glass, just like the physicist.

Yves's work has been recognized and praised by the industry. However, when he was fired in 1992 because of the closure of his laboratory, he returned to his hometown town and started his own holographic technology research as a freelancer, the situation was completely different. It took him about two years to develop all necessary equipment, including the most important portable holographic portrait camera. But when all this was ready, the only manufacturer who produced the film he needed suddenly decided to stop producing it. After inventing the cow, Yves had to teach himself how to make grass.

In the following years, Yves Ghent taught himself the relevant chemical principles in his humble laboratory and practiced them repeatedly. Philip's joining helped him a lot. Later, they finally invented a photographic emulsion called "Ultimate". Like other photographic emulsions, the main component of Ultimate is silver bromide particles with excellent photographic performance, but the diameter of silver bromide particles in Ultimate is only 10 nm, which is110 to100 of the photosensitive particles on ordinary film. It is these tiny particles that enable "Ultimate" to record every detail, down to the smallest detail, and simultaneously record three colors of red, green and blue on the same photosensitive layer.

Eve found what he called "the emulsion that people have been looking for for for 30 years", but he still has a long way to go. He made the whole plan to copy the murals of Little Wei Yan Cave, but he had no recourse because he could not find the authority of the government. He also suggested building a holographic portrait gallery for visiting celebrities for Disneyland in Paris, but the negotiations were postponed. Everyone who has seen his works admits that it is a perfect hologram, but French investors are too cautious. Not only do they want geese that lay golden eggs, but also a group of such geese lay golden eggs on a large scale in an industrialized way before they are willing to pay for themselves. In order to seek investors, the Ghent brothers and their father even thought about immigrating to Quebec.

The turnaround occurred after an American partner joined. The machine he owns can copy the holographic image on the "ultimate" master to a polymer material made by DuPont. Although these images are not up to the image level of "ultimate" film, they are far superior to holographic images on polymer materials. With the large-scale production of holographic images on this DuPont material, industrial production using "ultimate" film is just around the corner. In addition, the approval of the International Holographic Producers Union also added weight to the work of the Ghent brothers.