, also known as holography, is a very attractive technology in optics. We all have this experience that the oil film spilled on the road will show many colors in the sun, and the same situation will be seen on the blown soap bubbles. The reason is that the reflected light on both sides of the soap bubbles interferes, which is called the film interference phenomenon of light. Light is the life of photography, and light has many characteristics, such as dispersion and scattering. Experienced photographers can make full use of these phenomena to turn harm into advantage, thus adding some novel effects to their works. Camera lens is composed of multiple groups of lenses. In order to avoid the reflection loss of light on the lens surface, people invented the coating technology of the lens, so that the light with a certain wavelength can cancel each other when reflected, so as to increase the light entering the lens and make the image clearer. Similarly, people have developed holographic photography technology with stereoscopic effect by using the interference characteristics of light waves. Holography was once a patented technology for scientists to carry out scientific research, but now ordinary people can master it after a certain amount of study, such as fake cards commonly used in credit cards or book covers, which are three-dimensional imaging things, showing colorful reflected light in the sun.
The word "hologram" is familiar to us, and it is associated with the human body hologram in the ear acupuncture. The human ear is a microcosm of the human body, which corresponds to various organs of the human body. From here, people further study that any part of the human body has the information of the whole body, so it is called hologram, and it is easy to understand holography.
the difference between holography and ordinary photography
general photography of holographic photography
recording method: object beam light and reference beam optical lens imaging (object beam light)
recording content: the intensity and phase information of scattered light of the object; the intensity of the scene itself or reflected light
imaging medium is called holographic film (full gray tone) after recording;
generally, the image observation method is directly watched by the eyes through laser reduction.
color shows color interference fringe image, color object image
image features a three-dimensional scene, which only scatters light but has no real plane object image
1. What is the interference phenomenon of light
In the mechanics of physics class, we have done the interference experiment of water waves, and according to the fluctuation characteristics of light, people have successfully observed the interference and diffraction phenomenon of light waves. In order to get two beams of light with the same frequency, let the light shoot from a slit to two small holes of the second screen at the same time, and the two beams of light appear interference fringes behind the screen. The appearance of the fringes is because the peaks and valleys of the two beams of light will be strengthened due to the superposition (in-phase) light, and the light will be weakened when they cancel each other (in-phase). This phenomenon made Stephen Benton, a physicist at the Massachusetts Institute of Technology in the United States, discover that there is a high technology hidden behind it, so as to make further research on this technology < P > Second, the characteristics of holographic images < P > The principle of holography was put forward by British physicist Dennis dennis gabor in 1947, and the scientist himself won the Nobel Prize for it. When shooting a holographic image, the light wave itself and the relative phase of the two beams are recorded. The phase is caused by the position difference between the real object (blue light in the picture) and the reference light (red light in the picture). We can't see the imaging of the object from the interference fringes on the hologram. We must use cohesive laser to accurately aim at the target to illuminate the hologram, so as to reproduce all the information of the object light. A man named Banton later discovered a simpler way to restore images by using white light, thus making this technology gradually move towards the practical stage. When the National Geographic magazine first used a white hologram on its cover, its sales volume increased from 1 million copies to 16 million copies after reprint. This technology was later spread from the United States to Europe and other countries, and was widely used in counterfeit technologies such as credit cards. Laser holography is also popular all over the world.
Holography is a kind of photography that records images and reproduced images by the interference of laser light waves. It is completely different from the general stereo photo technology. We can watch all sides around it, but we can't touch the real objects. Its remarkable characteristics and advantages are as follows:
1. The reconstructed three-dimensional images are conducive to preserving precious works of art for collection.
2. When shooting, every point is recorded on any point of the hologram. Once the photo is damaged, it doesn't matter much.
3. Holograms have strong stereoscopic effect and vivid images, and can be displayed in various exhibitions with the help of lasers, which will get very good results.