Can Fiber Optic Cables Create Coherent Light Circuits?

[vin300]

By what we know, optic cable can guide waves by TIR. So what if it guides into itself, for instance, to keep it virtually flat and high angle reflection; I lay cable around the circumference of the planet and it loops back into itself with double entry: one guided and other newly introduced with my original light source, would that 1)create a similar effect as laser coherence thus enabling a means of high energy concentration or 2) create a purely probabilistic output of constructive and destructive interference thus limiting the power to a certain value of standard deviation after infinite cycles?

 

[Drakkith]

1)create a similar effect as laser coherence thus enabling a means of high energy concentration

Nope. The light would be incoherent due to the availability of multiple paths to take while in transit through the cable and dispersion.

2) create a purely probabilistic output of constructive and destructive interference thus limiting the power to a certain value of standard deviation after infinite cycles?

Some amount of light is absorbed by the cable every unit of distance, so you're already limited to how long of a cable you can bend into a circle before you lose essentially all of the input light before it comes back around.