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| title | chunk | source | category | tags | date_saved | instance |
|---|---|---|---|---|---|---|
| History of metamaterials | 2/5 | https://en.wikipedia.org/wiki/History_of_metamaterials | reference | science, encyclopedia | 2026-05-05T03:39:47.132262+00:00 | kb-cron |
=== Jagadish Chandra Bose === Jagadish Chandra Bose was a scientist involved in original microwave research during the 1890s. As officiating professor of physics at Presidency College he involved himself with laboratory experiments and studies involving refraction, diffraction and polarization, as well as transmitters, receivers and various microwave components. He connected receivers to a sensitive galvanometer, and developed crystals to be used as a receiver. The crystals operated in the shortwave radio range. Crystals were also developed to detect both white and ultraviolet light. These crystals were patented in 1904 for their capability to detect electromagnetic radiation. Furthermore, it appears that his work also anticipated the existence of p-type and n-type semiconductors by 60 years. For the general public in 1895, Bose was able to remotely ring a bell and explode gunpowder with the use of electromagnetic waves. In 1896, it was reported that Bose had transmitted electromagnetic signals over almost a mile. In 1897, Bose reported on his microwave research (experiments) at the Royal Institution in London. There he demonstrated his apparatus at wavelengths that ranged from 2.5 centimeters to 5 millimeters.
== Early chiral media == In 1898, Jagadish Chandra Bose conducted the first microwave experiment on twisted structures. These twisted structures match the geometries that are known as artificial chiral media in today's terminology. By this time, he had also researched double refraction (birefringence) in crystals. Other research included polarization of electric field "waves" that crystals produce. He discovered this type of polarization in other materials including a class of dielectrics. In addition, chirality as optical activity in a given material is a phenomenon that has been studied since the 19th century. By 1811, a study of quartz crystals revealed that such crystalline solids rotate the polarization of polarized light denoting optical activity. By 1815, materials other than crystals, such as oil of turpentine were known to exhibit chirality. However, the basic cause was not known. Louis Pasteur solved the problem (chirality of the molecules) originating a new discipline known as stereochemistry. At the macroscopic scale, Lindman applied microwaves to the problem with wire spirals (wire helices) in 1920 and 1922. Karl F. Lindman, from 1914 and into the 1920s, studied artificial chiral media formed by a collection of randomly oriented small spirals. He was written about by present-day metamaterials scientists: Ismo V. Lindell, Ari H. Sihvola, and Juhani Kurkijarvi.
== 20th century artificial dielectrics ==