Technological progress allows us to create devices that we could only dream of before. Now you will not surprise anyone with devices with wireless communications, satellite dishes and flights into outer space. Over the past centuries, many discoveries and inventions have been made, thanks to which at the moment it is possible to produce modern equipment, medications and various devices that allow for complex surgical operations. For example, Fresnel diffraction revealed some information about the nature of light, unknown until then.
Augustine J. Fresnel (1788–1827)
The French scientist was born in an educated family, his father was an architect. As a child, Augustin Jean was not such a developed child, at the age of 8 he could barely make out the letters. And at that time no one could even imagine that one of the most important phenomena of physics — Fresnel diffraction — would be named in his honor.
The scientist could enter a regular school only when he turned 13. After studying at Cannes, the future physicist enters the Paris school of the polytechnic, where he impresses all teachers and comrades with the mental abilities that had developed at that time. After graduating from this educational institution, Fresnel goes to the "School of bridges and roads" and receives the profession of engineer.
O. Fresnel was awarded in 1827 the highest value award of the Royal Society of London - the Rumford Medal. Also, the scientist was at the Paris Academy. Thanks to his developments in the field of light optics, the working methods of beacons have changed.
Fresnel Experience
Fresnel diffraction is an experimental picture that proves that light has wave properties. With his experience, the physicist confirmed Huygens' theory and supplemented Jung T.'s experiments with his research using new interference devices.
Diffraction of light is understood to mean its ability to go around obstacles, while falling into the shadow region. Fresnel conducted experiments with an obstacle, where light was reflected from the edge of the ball, and the passage of the beam through the gap. The physicist presented the results of his labors in his Memoirs on Diffraction.
In addition, in an experiment proving the existence of the phenomenon of interference in light nature, the scientist used a setup called the "Fresnel mirror." This device represents two reflective sheets that are located relative to each other at an angle slightly less than 180 °. Light from one source was supplied to these mirrors, which, when reflected, created two reflections with the same phase difference. In this case, the two rays were combined and gave a total of alternating dark and light stripes.
Application of Fresnel discoveries
Now you can see the widespread use of the results of the experiments of the French scientist. So, Fresnel mirrors are used in the development of devices that accumulate solar energy. For example, a concentrator in the construction of which this interference device is used is distinguished by a maximum value for receiving solar energy. It is used as an apparatus for heating water, one of the units of a power plant and for other industrial purposes.
Another device proposed by the French scientist and known as the Fresnel prism is used in the treatment of strabismus. At the moment, new elastic models of this device have been developed, which are a plate of transparent plastic material. One side of such a prism is made with rasters, and the other is smooth. This device is glued to the glasses, while it is used for any form of strabismus.
Fresnel diffraction is used in focusing in optical instruments (telescopes, binoculars). This discovery is one of the decisive ones in optical physics, on which many studies are based.