Multi-core optical communications fiber
AssigneeInternational Telephone and Telegraph Corporation
InventorJames E. Goell
Life of this patent
Estimating the term…
Abstract
Methods and apparatus are disclosed for providing a multipath optical communications system within a single fiber. One embodiment comprises a concentric multi-core optical fiber having an inner core for transmitting information and an outer core for transmitting a security signal. Attempted access to the inner core causes a decrease in the security signal intensity alerting the operator to the attempted intrusion.
Claims16
A multiple core optical fiber comprising:
- an inner core of light transmission material having a first index of refraction;
- an inner cladding layer of light transmissive material surrounding said inner core having a second index of refraction lower than the first index of refraction for confining light energy within said inner core;
- at least one outer core of light transmissive material surrounding said inner core and cladding having an index of refraction higher than said second index of refraction;
- and
- at least one outer cladding layer of light transmissive material surrounding said outer core and having an index of refraction lower than said outer core for confining light energy within said outer core.
A fiber optic communication system comprising in combination:
- an optical fiber having a plurality of concentric layers of alternating higher and lower index of refraction light transmissive material;
- first optical transmission means for transmitting information data through one of said layers of high index material;
- second optical transmission means for transmitting optical energy through another of said layers of high index material;
- first optical receiver means for receiving said information data from said one layer of high index material;
- and
- second optical receiver means for receiving said optical energy from said other layer of high index material.
A method for transmitting secured information data in optical communication systems comprising the steps of:
- providing a multi-layered optical communications fiber having alternate layers of high and low index of refraction light transmissive materials;
- transmitting optical communication through one of said layers of high index of refraction material;
- transmitting optical energy through another of said layers of high index of refraction material;
- and
- monitoring said optical energy in said other layer to determine any loss in said optical energy.
Dependencies are inferred from the claim text.