Patent ID: 9574911
Date: 2017-02-21
CPC Classifications: G01D,G01J,G01K,G01L,G01N,G02B

Claim:
1. An optical fiber comprising: a first core, a second core, and a cladding surrounding both of the cores, wherein at least one of the following conditions is satisfied: (i) each core is configured with a refractive index profile that is substantially uniform along its length and differs from the refractive index profile of the other core; (ii) each core is configured with a doping concentration that differs from the doping concentration of the other core; (iii) each core has a different composition than the other core; (iv) the optical fiber further comprises a refractive index ring configured to surround at least one of the cores; (v) the cores are configured such that the distance between the center of the cores is at least 25 μm; and (vi) the cores are configured such that the distance between the center of the cores is at least 25 μm and each core is surrounded by a low refractive index ring; wherein each core is configured to exhibit a single Brillouin frequency shift peak (BFS peak) when light is launched into the core, and further wherein the BFS peak of each core differs from the BFS peak of the other core in terms of frequency and each core is configured to exhibit a Brillouin frequency shift of at least 30 Mhz relative to the other core.