Re:A Gazillion-Dollar Standoff over Two High-Frequency Tradi...
by hyeonwho4 on Sunday March 10, 2019 @06:30PM
(#19355077)
That's not true. The typical total reflection angle in single mode fiber optic cable is less than 4 degrees. The refractice index of glass, however, is about 1.45. So almost all the slowdown is due to the glass directly slowing down the signal.
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Re:A Gazillion-Dollar Standoff over Two High-Frequency Tradi...
by madengr on Sunday March 10, 2019 @07:10PM
(#19355339)
Though you can still get a group delay (slower than free space) in vacuum filled RF waveguide. When you break down the single mode, it appears to be zig-zagging through the waveguide (bouncing off the walls), and slows down as cutoff is approached. Like in fiber, the modal dispersion is separate from the material dispersion.
AT&T was going to build out a cross country, single mode, circular waveguide network in the 60’s, but was obsoleted due to fiber. Maybe that’s what the HFT ought to due, or maybe air-line coax.