Optical fiber coupler, method for producing the same and optical amplifier using the same
AssigneeKYOCERA Corporation
InventorsMichitaka Okuta, Hiromi Ajima
Life of this patent
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Abstract
In an optical amplifier wherein pumping laser light and signal laser light are multiplexed and supplied as input to a fiber doped with a rare earth element, by decreasing the number of connected sections, loss due to the connection to the rare earth-doped fiber is decreased, thereby to improve the amplifying characteristics and to simplify the production step. a pair of fibers, each which is connected by a transmitting optical fiber 1 and a rare earth-doped fiber 4, at a connected sections, are heated and fused with each other are aligned in part length to a fused jointed portion 3 which is stretched in the vicinity of the connected section 2 on the rare earth-doped fiber side, thereby forming an optical coupler.
Claims10
A method of producing an optical fiber coupler comprising the steps of:
- fusing an ordinary optical fiber and a rare-earth doped optical fiber end to end at a connected section to form a single joint fiber;
- disposing a pair of single joint fibers in parallel contact with the connected sections thereof aligned;
- heating to fuse a region of the pair into a fused fiber region;
- and
- elongating the heated fused fiber region creating a fused and elongated region to adjust a diameter thereof.
An optical fiber coupler for multiplexing pumping laser light and signal laser light having ordinary optical fibers on an input side and at least one rare-earth doped optical fiber on an output side, comprising:
- a pair of input optical fibers comprising ordinary optical fibers;
- a pair of output optical fibers comprising rare-earth doped optical fibers;
- a pair of connected sections, each connected section formed by fusing an input optical fiber end to end with an output optical fiber to create a connection;
- and
- a fused and elongated portion having a first end region and a second end region, the fused and elongated portion composed primarily of rare-earth doped optical fiber with no ordinary optical fiber connecting the first end region with the second end region, said portion formed by aligning the connections of the pair of connected sections in parallel, heating a length of the aligned sections to fuse them along the length and elongating the heated fused region to reduce a diameter of said portion to a desired diameter, whereby pumping laser light entering a first input optical fiber at the input side and signal laser light entering a second input optical fiber at the input side are multiplexed in the fused and elongated portion and exit the output side as multiplexed signal light.
Dependencies are inferred from the claim text.