2 ms·
Though surely the repeaters in a cable, such as the one in the article, presents hard limits?
by tjoff 2y ago
Though surely the repeaters in a cable, such as the one in the article, presents hard limits?
- markonen 2y agoThey’re probably amplifiers rather than repeaters. Optical amplifiers don’t need to decode the signal to work. Here’s Wikipedia on erbium-doped fiber amplifiers: > A relatively high-powered beam of light is mixed with the input signal using a wavelength selective coupler (WSC). The input signal and the excitation light must be at significantly different wavelengths. The mixed light is guided into a section of fiber with erbium ions included in the core. This high-powered light beam excites the erbium ions to their higher-energy state. When the photons belonging to the signal at a different wavelength from the pump light meet the excited erbium ions, the erbium ions give up some of their energy to the signal and return to their lower-energy state. https://en.wikipedia.org/wiki/Optical_amplifier https://en.wikipedia.org/wiki/Optical_amplifier
- wiml 2y agoI think they're mostly laser amplifiers these days. So they're agnostic to modulation or WDM. But I assume there's still a noise/gain tradeoff.