How do we use light?
It is hard to imagine what the life of a modern person would look like without light. In clear weather, the night sky is able to brightly illuminate our way home. But what about the rest of our habits? Working late, reading a book before going to bed… In addition to satisfying these small needs, light significantly changes our life in many areas, making it more convenient, safer and simply more beautiful.
Using light itself
Light not only illuminates, but also colors our life. Color and two-dimensional spread of light is used to create a variety of interior and exterior design lighting, for digital billboards, etc. Today the city at night looks much brighter and more colorful than in the daytime. These properties of light are also used for display monitors, which serve as the interface between computers and humans.
The sun’s rays have a strong effect on biological tissues. That is why long stay on the beach under the scorching sun leads to very unpleasant consequences in the form of sunburn. But the same feature allows the use of UV rays to sterilize objects from bacteria and viruses, which has recently become especially important.
Using a lens, we can direct a narrow strip of normal daylight to a specific point and thus make a hole in the paper. A high power laser can do the same in almost any material with micron precision. Therefore, lasers are used in areas such as surgery and ophthalmology in medicine, as well as for cutting and welding metal in industry.
Some substances tend to harden when exposed to UV rays. Thanks to these properties, we have stereolithography 3D printers that can print a huge variety of objects. Also, using UV rays, you can glue some substances that are used in industrial processes and dentistry.
X-rays, γ-rays and β-rays are all of the nature of light. They easily penetrate the human body, therefore they are used in the field of medicine for the diagnosis and treatment of diseases.
Using light to define properties of objects
Light allows a person to acquire such superpower as the ability to see through objects. With the help of spectral analysis, it is possible to determine what components an object consists of. For example, to study the composition of blood in the course of medical tests or to determine the presence of various chemical compounds in products (the amount of sugar or proteins), the degree of ripeness, and even the freshness of the product.
A TV- or photo- camera records and transmits images using a photodetector. This information is processed, analyzed and can be used not only to create photographs, but also in many other areas. For example, for medical diagnostics, testing of territories contamination, in scientific research, in the field of security.
By shining light on an object and measuring the time of flight (TOF), one can determine the distance to the object. We have learned to use this property in such areas as automated driving, production of cleaning robots, and three-dimensional measurement.
Using light to convey information
To transmit information people use radio waves and wires. But light allows us to do this with even greater precision — at the speed of light. This property of light is one of the most promising today. It is used in various types of communication: in global fiber networks and optical Internet networks, in wireless communication over short distances (for example, for remote control of devices).
To encode information on CD, DVD and Blu-rays, interleaving of pits and lands is used. If a narrow laser ray is directed at them, the way of its reflection can be read as a digital signal. This way light can be used to store and move a large amount of information.
Achievements of photonics are used in a wide variety of industries and in almost all areas of our life. The pace of this discipline development allows us to say that the new era of humanity will be a real era of light. Sounds optimistic! Let it be.