Optical waveguides – Optical fiber bundle
Reexamination Certificate
2000-08-28
2002-12-10
Spyrou, Cassandra (Department: 2872)
Optical waveguides
Optical fiber bundle
C385S146000, C385S096000, C385S050000, C372S070000, C359S341100
Reexamination Certificate
active
06493492
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to optical fibers and optical fiber amplifiers.
2. Discussion of the Related Art
Some optical amplifiers use a doped optical fiber to perform optical amplification. The doped amplifier fiber receives both multi-mode pump light and a single-mode input optical signal for amplification. One arrangement introduces both the pump light and the input optical signal into one end of the amplifier fiber. Since the pump light and input optical signals come from separate fibers, these fibers are often combined into a bundle prior to coupling to the amplifier fiber. The fiber bundle improves the coupling with the amplifier fiber.
FIG. 1
shows a portion of a fiber amplifier
10
that uses a conventional fiber bundle
12
. The fiber bundle
12
optically couples through end
13
to amplifier fiber
14
, e.g., a multi-modal fiber having erbium and/or ytterbium dopants. The fiber bundle
12
incorporates two or more pump fibers
16
-
21
and input fiber
24
. Each pump fiber
16
-
21
receives pump light at one end from a single laser diode
27
-
32
and transports the light by total internal reflection to end
13
, which couples to the amplifier fiber
14
. The input fiber
24
delivers the optical signal to be amplified. Near the end
13
, fibers
16
-
21
,
24
of fiber bundle
12
have been bonded together.
FIG. 2
is a cross-sectional view of the end
13
of the fiber bundle
12
shown in FIG.
1
. The input fiber
24
is a single-mode optical fiber located at the center of the fiber bundle
12
. The pump fibers
16
-
21
are multi-mode optical fibers located around the circumference of the input fiber
24
.
The complete fiber bundle
12
and amplifier fiber
14
may have different outer diameters. If the diameters differ, a region
26
of the fiber bundle
12
adjacent the joint end
13
is tapered so that the fiber bundle's diameter matches that of the amplifier fiber
14
at the joint. Matching the outer diameters improves light transfer from the fiber bundle
12
to the amplifier fiber
14
.
The amplifier fiber may have an outer core with a polygonal cross section that enhances the coupling of pump light to the optically active dopants.
Various features of the fiber bundle
12
and amplifier fiber
14
improve optical couplings in fiber amplifier
10
. But, still better optical couplings are desirable to push amplifiers to even higher optical gains.
SUMMARY OF THE INVENTION
In one aspect, the invention features a manufacture. The manufacture includes a first optical fiber and a plurality of second optical fibers. The second optical fibers have cross sections with aspect ratios of two or more. Distal sections of the fibers form a bonded structure. In the bonded structure, each distal section bonds along a length to another one of the distal sections and to the first optical fiber.
In a second aspect, the invention features an apparatus. The apparatus includes a plurality of laser diodes and a fiber bundle. The fiber bundle includes a first optical fiber and a plurality of second optical fibers. The second optical fibers have cross sections with an aspect ratio of two or more. Distal sections of the fibers form a bonded structure in which each section bonds along a length to another one of the sections and to the first optical fiber. Each laser diode is optically coupled to one of the laser diodes.
In a third aspect, the invention features a process for amplifying an input optical signal. The process includes transmitting pump light from laser diodes into associated pump optical fibers. The fibers have cross sections with aspect ratios of at least two. The process also includes delivering the transmitted pump light to one end of an amplifier optical fiber and transmitting the input optical signal into one end of the amplifier optical fiber.
REFERENCES:
patent: 2992516 (1961-07-01), Norton
patent: 4547040 (1985-10-01), Yamamoto
patent: 4763975 (1988-08-01), Scifres
patent: 5263036 (1993-11-01), De Bernardi
patent: 5999673 (1999-12-01), Valentin et al.
Boutsikaris Leo
Lucent Technologies - Inc.
McCabe John F.
Spyrou Cassandra
LandOfFree
Fiber bundle and optical amplifier does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Fiber bundle and optical amplifier, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Fiber bundle and optical amplifier will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2931359