Yasuhiko Arakawa Yasuhiko Arakawa Yasuhiko Arakawa (Japanese , "Arakawa Yasuhiko"; born 6 November 1952) is a Japanese physicist. His research focuses on semiconductor physics, including growth of nanostructures and their optoelectronic applications. Among his main achievements are the proposal of the concept of quantum dots and their application to quantum dot lasers, the observation of exciton-polariton Rabi-splitting in a semiconductor microcavity, or, recently, the first 3D photonic crystal nanocavity lasers with quantum dot gain. Yasuhiko Arakawa received a B.S. degree in 1975 and a Ph.D. degree in 1980, respectively, from the University of Tokyo, both in Electronics Engineering. In 1981 he became
Battle of Two Rivers Battle of Two Rivers The Battle of Two Rivers was fought between the Picts and Northumbrians in the year 671. The exact battle site is unknown. It marked the end of the Pictish rebellion early in the reign of Ecgfrith, with a decisive victory to the Northumbrians. Attestation of the battle is limited to the account in Stephen of Ripon's "Vita Sancti Wilfrithi". During the 7th century, the Northumbrians gradually extended their territory to the north. The Annals of Tigernach record a siege of "Etain" in 638, which has been interpreted as Northumbria's conquest of Din Eidyn (Edinburgh) during the