I found a technology that Wikipedia attributes to 1978: Fiber optic WDM https://en.wikipedia.org/wiki/Wavelength-division_multiplexing https://en.wikipedia.org/

I found a technology that Wikipedia attributes to 1978: Fiber optic WDM https://en.wikipedia.org/wiki/Wavelength-division_multiplexing https://en.wikipedia.org/wiki/Wavelength-division_multiplexi... It was really interesting to learn how long this tech has been in use.