Optical waveguides – Optical fiber waveguide with cladding – Utilizing multiple core or cladding
Reexamination Certificate
1999-07-27
2001-10-16
Palmer, Phan T. H. (Department: 2874)
Optical waveguides
Optical fiber waveguide with cladding
Utilizing multiple core or cladding
C385S122000
Reexamination Certificate
active
06304705
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to optical fiber and methods of manufacturing optical fiber. More particularly, the invention relates to optical fiber coatings and methods of coating optical fibers.
2. Description of the Related Art
High performance communications systems, i.e., those systems having gigabit transmission speeds, are being made possible by improving the bandwidth of optical fiber. However, achieving those desired transmission speeds in multimode fiber has been hindered by problems such as dispersion. Because multimode optical fibers are capable of propagating more than one mode of optical energy, an inherent problem with dispersion exists. Such dispersion, more specifically known as modal dispersion, is the broadening or spreading of an optical energy output pulse caused by delays resulting from various pulse modes traveling through the optical transmission medium at different speeds. Such dispersion can be managed by mode mixing or mode coupling, i.e., the mixing or scrambling of the various modes in such a way that effectively reduces the difference in travel times of the various pulses modes. The reduction in dispersion improves the bandwidth of the multimode optical fiber.
It has been recognized that certain microbending (i.e., microscopically small deviations in the fiber axis) of multimode fiber often causes advantageous mode coupling or mode mixing. That is, the introduction of perturbations in the multimode cladding modes enhances mode coupling. Conventional approaches to inducing microbending has varied from externally inducing bends in the outer regions of the fiber (see, e.g., U.S. Pat. No. 4,038,062, which is co-owned with this application) to internally applying refractive index perturbations in the optical fiber preforms that subsequently are drawn into optical fibers (see, e.g., U.S. Pat. Nos. 5,867,616 and 5,613,028). Many conventional methods for inducing microbending techniques have had difficulty in controllably introducing perturbations and reliably reproducing the desired microbends. Furthermore, many conventional microbending techniques are undesirable from the standpoint of manufacturing cost and efficiency.
Accordingly, there remains a need for controllably inducing microbends in optical energy transmission medium such as optical fibers to enhance mode coupling therein.
SUMMARY OF THE INVENTION
The invention is embodied in a system for transmitting optical energy including a source of optical energy, an optical energy transmission medium such as an optical fiber and a receiver of optical energy. The optical energy transmission medium includes a plurality of particles such as fumed silica formed therein for inducing microbending of the optical energy transmission medium, thus promoting advantageous mode coupling, which improves bandwidth potential, e.g., by reducing modal dispersion. The particles are incorporated into, e.g., one or more layers of a coating region formed around the optical fiber portion of the optical energy transmission medium and/or one or more layers of a buffer region formed around the coating region, which includes the coloring layer portion of the buffer region.
An alternative embodiment of the invention includes a method of making an optical energy transmission medium. The method includes providing an optical energy transmission medium with a core region, a cladding region, and a one or more coating region layers having a plurality of particles therein, and forming one or more buffer region layers around the coating region. Also, the method includes providing an optical energy transmission medium with the plurality of particles disposed in one or more coating region layers and/or one or more buffer region layers. The particles form controlled perturbations along the optical fiber that enhance mode coupling. The quantity and size of the particles affect the degree of microbending and thus the degree of mode coupling.
Yet another alternative embodiment of the invention includes a medium for transmitting optical energy within an optical communications system. The medium is, e.g., an optical fiber having a glass core and cladding region surrounded by a coating region made of ultraviolet (UV)-cured acrylate or other suitable material and having a plurality of particles such as fumed silica disposed therein. The optical fiber is surrounded by a buffer region. Also, the medium includes a configuration in which the coating region and/or the buffer region has particles disposed therein. The particles form perturbations in the optical fiber in a manner that advantageously enhances mode coupling.
Still another alternative embodiment of the invention includes a method of transmitting optical energy in an optical communications system. The system includes an optical energy source, optical energy receiver and an optical energy transmission such as an optical fiber coupled therebetween. The transmission method includes providing an optical energy transmission medium having a plurality of particles within one or more coating region layers and/or one or more buffer region layers that induces microbending of the optical energy transmission medium and enhances mode coupling therein. The transmission method also includes transmitting optical energy from the source to the receiver through the optical energy transmission medium. The enhanced mode coupling from microbending caused by the particles improves the bandwidth transmission characteristics of the transmission system.
REFERENCES:
patent: 4038062 (1977-07-01), Presby
patent: 4410344 (1983-10-01), Iyengar
patent: 4629286 (1986-12-01), Fuse et al.
patent: 4637686 (1987-01-01), Iwamoto et al.
patent: 4702016 (1987-10-01), Gartside et al.
patent: 4913859 (1990-04-01), Overton et al.
patent: 5000772 (1991-03-01), Petisce
patent: 5117472 (1992-05-01), Blyler, Jr. et al.
patent: 5147433 (1992-09-01), Petisce
patent: 5613028 (1997-03-01), Antos et al.
patent: 5838862 (1998-11-01), Chien
patent: 5867616 (1999-02-01), Antos et al.
patent: 6108476 (2000-08-01), Iimura
patent: 19810812 (1999-09-01), None
Kalish David
Neveux, Jr. Paul Emilien
Ritger Albert John
Taylor Carl Raymond
Turnipseed John Michael
Harman John M.
Lucent Technologies - Inc.
Palmer Phan T. H.
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