Pushing Lasers Past 100 GHz
Researchers at Ruhr-University Bochum have designed a laser capable of having modulation frequencies above 100 GHz. Such lasers would be of great value to the Internet in the future. The current limit to lasers in telecommunications are below 50 GHz, so the new laser design could more than double the speed of the internet, of optical lines. This record setting design achieves its high speed by controlling the spin of electrons used to power the laser. Most semiconductor lasers are powered by electrons of arbitrary spin, but the new design only allows electrons with a specific spin to power the laser. This causes the semiconductor to emit two laser modes at different frequencies. With a microresonator, the two modes can generate a single frequency in excess of 100 GHz.