Humans have a lot of movements about light, which have existed since primitive times. For wild animals, such strong light at night means that they are vigilant when traveling at night. Later, human social organizations became more and more complex, and there were more ways to transmit information by light. Take the beacon tower as an example, you can only see it when there is smoke. These methods are still relatively extensive. In the era of great navigation, human beings invented semaphores, and under the condition of light, they transmitted information through pre-arranged semaphore gestures. Light itself has many characteristics. Light with different colors and frequencies has different refractive indexes in the same medium. For example, traffic lights use the color of light to convey information.
The most extensive aspect of modern optical transmission information is information technology, and devices are linked by optical fibers. The so-called optical fiber is a kind of light-transmitting linear material, which has a strong reflection on the outer surface. The light is totally reflected on the outer surface, and the information contained in it is interpreted by using a programmed program after being transmitted to the terminal. High transmission speed, high efficiency, low energy consumption, long information transmission distance and high speed. Modern Internet is developed based on optical fiber. There is also optical quantum communication, which does not use quantum to transmit information, but uses optical quantum to encrypt information and also uses light to transmit information.
Information transmission can make use of human senses, such as smell, vision, hearing, temperature perception and so on. Vision is the use of light. When people grow up like this, it is natural to transmit information with light.
Of course, light can transmit information, and optical fiber is an example.
Nowadays, information technology is very developed and the Internet is very popular, so modern people visit websites through broadband connections. In order to ensure the rapid and accurate transmission of information, the development of optical fiber technology plays an important role.
Starting from a common optical phenomenon, when incident light enters medium 2 (medium with low optical density) with high refractive index from medium 1, the light will deviate from the normal after refraction. The greater the incident angle, the greater the deviation of refracted light. When the incident angle is equal to the critical angle c, the light will be refracted along the interface. If the incident angle is greater than the critical angle, according to the law of reflection, the light will be completely reflected into the medium 1. This phenomenon is called total internal reflection. See the picture above
The center of a simple optical fiber is composed of a medium with high optical density, and the medium with low optical density forms a narrow tube on the outer layer. The material of the medium is usually glass or plastic. If light is guided to one end of an optical fiber, it will be transmitted in the optical fiber. When light meets the interface between the center layer and the outer layer, total internal reflection occurs and reflects back to the center. Although light travels in a straight line, it will travel in the direction of optical fiber, even if it is curved. Optical fiber is widely used in various fields from communication to medical equipment production (such as endoscope, optical fiber sensor or optical fiber decoration).
Optical fiber communication in this era uses the change of light intensity to express different signals. If the incident light carrying information is directed at one end of the optical fiber, the optical fiber will transmit the light to the receiver at the other end. The converter can restore the original information. Because the loss of light in the process of transmission through glass fiber is not great, information can be transmitted over a long distance without intermediate transmission stations. A few microns (thinner than a human hair) optical fiber can transmit10 million pulses per second. Due to the advantages of optical fiber over copper wire, optical fiber is gradually replacing copper wire as the main communication medium.
Hello, light can not only transmit information, but also be information in most cases in our lives.
First, let's talk about how light transmits information. For example, in our ubiquitous network world, most of them rely on light to complete information transmission. Two people are in place A and place B respectively. If they want to communicate with each other, they must first pull an optical fiber, each holding one end. At one end, one person lets light pass through an optical fiber to another person. As soon as this light goes out, it carries information and spreads it. But two people must have the same codebook to compile the information carried by light.
Secondly, let's discuss the situation that light itself is information. This kind of situation is very common in our daily life. For example, judging the maturity of grapes by distinguishing colors. (The frequency of reflected light from grapes is processed by optic nerve to form an image in the brain) When we see blue grapes, we judge that the grapes are not ripe, and when we see purple grapes, we judge that the grapes are ripe. This is an example of light itself as information.
The above answers hope to help you answer your questions.
WIFI, which is indispensable every day, is the signal that transmits information to the router through optical fiber.
Of course, for example, when you look at your mobile phone, read a book, see everything in the world, the light enters your eyes, and the information you see in your mind. There are more specific points, such as optical fiber communication, that is, the electrical signal is converted into laser, and the laser is transmitted to the remote receiving end through optical fiber and then converted into electrical signal. The receiver gets the information. In this process, only the information in the optical fiber is transmitted by light.
Light is a part of electromagnetic waves.
Electromagnetic waves can transmit information.
Light can also convey information.
Optical fiber materials transmit information through light. It not only transmits information but also carries energy.
For example, a prism can be used to carry out the dispersion experiment of light, and a spectrometer can be made by using this principle. Through the analysis of cosmic rays, it is found that some light is different from the spectrum, and one of them is called red shift. Scientists calculate the expansion speed of the universe through this phenomenon. This is the world that light tells us.
Light can spread what you already know has happened. In a way, according to Einstein's theory, if you want to go back to the past, you must be faster than the speed of light. At that time, you will see everything that happened in Nepal before. Recently, many countries jointly collected data and printed the first photo of a black hole. However, this photo is what a black hole looked like 46 million years ago, and it is the best example of light spreading information.