The world's longest laser created

时间:2019-03-02 14:07:00166网络整理admin

AN OPTICAL fibre 75 kilometres long has been transformed into the world’s longest laser, a feat its inventors hope will improve long-distance transmissions. Because optical fibres lose 5 per cent of their power for every kilometre, the signal must be amplified. Now Juan Diego Ania-Castañón and his team at Aston University in Birmingham, UK, have dispensed with amplifiers by making the entire fibre behave like a laser. Lasers inject light at each end which continually excites some of the fibre’s atoms to a higher energy,