Atom Cloud Gives Light a New Color ⚡ экспресс
Experimentalists pulled off a record-breaking conversion of light from the near-infrared range (795 nm) into the telecom range (1367 nm) using cold rubidium atoms. The trick lies in diamond-type four-wave mixing, where atoms act as a nonlinear medium—much like a diamond’s facets bend light rays. The key insight came from studying the embedded spectra of electromagnetically induced transparency (EIT, where a medium becomes see-through for light), allowing the team to dial in the perfect conditions. Conversion hit 66% and 80% at optical densities of 75 and 110, respectively, smashing all previous records.
For a future quantum internet, light carries information through glass cables, but atoms often emit a color that fades fast. Physicists cooled rubidium atoms to near absolute zero, turning them into translators: they absorb red light and re-emit infrared—the hue that races through fiber. With lasers precisely tuned, these translators achieve 80% fluency—a conversion rate surpassing any past effort. The key was making the cloud transparent for the right color, a window into light-matter conversations. This shift of speed and color preserves the fragile quantum message. The infrared pulse can travel over 50 kilometers through fiber before losing half its strength—a direct line between distant quantum processors. The work stands on the atomic model of Niels Bohr and the light-matter insights of Roy Glauber and Serge Haroche.
🎯 An infrared photon can sail through 50 kilometers of standard fiber before losing half its intensity—like a whisper crossing a silent stadium.
🎬 Like the ansible in Ursula Le Guin’s novels that sent messages across galaxies, a quantum internet promises instant, unhackable global links—and this color-swapping cloud is the key.