263 results about "Buffer (optical fiber)" patented technology

A buffered optical fiber arrangement that includes a buffer tube in which is provided optical fibers and a texturized yarn coated with a water-swellable material. The filament diameter of the yarn used in the present invention may be between about 5 microns and about 100 microns, more preferably between about 10 and about 60 microns, still more preferably between about 20 and about 40 microns. The linear density, or denier in grams per 9000 meters, of the base yarn may be between about 100 and 1000, more preferably between about 200 and 600, or still more preferably between about 250 and 350. The degree of decrease in length (the "degree of texturizing") between the perfectly straight filaments before texturizing and the texturized filament may be between 1 percent and 90 percent, more preferably between about 2 percent and 50 percent, or still more preferably between about 5 percent and 25 percent.

The present invention provides optical fiber communication cable assemblies useful for separating and conveying individual fibers from a multiple optical fiber cable to connectors in a protective manner. The optical fiber cable assembly is suitable for outdoor use and includes a (i) cable with multiple optical fibers; (ii) a furcation unit attached to the cable for directing individual optical fibers from the cable to furcation legs; and (iii) multiple furcation legs receiving at least one of the optical fibers. The furcation legs include (i) a buffer tube surrounding the optical fiber; (ii) strength members surrounding the buffer tube; and (iii) a jacket surrounding the strength members. The furcation legs typically exhibit a tensile rating of at least about 50 pounds (lb_f), more typically 100 pounds (lb_f) or more. Moreover, the furcation legs typically exhibit total shrinkage of less than about 2 percent when cycled from +23° C. to −40° C. to +70° C. to −40° C.

Disclosed is an improved optical fiber that employs a novel coating system. When combined with a bend-insensitive glass fiber, the novel coating system according to the present invention yields an optical fiber having exceptionally low losses.

The coating system features (i) a softer primary coating with excellent low-temperature characteristics to protect against microbending in any environment and in the toughest physical situations and, optionally, (ii) a colored secondary coating possessing enhanced color strength and vividness.

The improved coating system provides optical fibers that are useful in buffer tubes and cables having relatively high filling coefficients and fiber counts.

An optical cable comprises a buffered optical fiber which is arranged within a buffer tube. The buffer tube is extruded around the buffered optical fiber such that a small gap, preferably in a range between about 40 μm and about 100 μm, is formed between the buffered optical fiber and the buffer tube. A layer of strength member elements is disposed around the buffer tube. A cable jacket is extruded around the strength member elements wherein the strength member elements are bonded to the cable jacket.

Consistent with the present disclosure, an encoder circuit is provided at a transmit side of an optical fiber link that maps an input sequence of bits of fixed length k a sequence of symbols of a codeword of length n, such that the symbols of the codeword define a predetermined transmission probability distribution. Preferably, each symbol of the codeword is generated during a corresponding clock cycle, such that after n clock cycles, a complete codeword corresponding to the input bit sequence is output. On a receive end of the link, a decoder is provided that outputs the k-bit sequence every n clock cycles. Accordingly, buffers need not be provided at the output of the encoder and the input of the decoder, such that processing of the input sequence, codewords, and output sequence may be achieved efficiently without large buffers and complicated circuitry. Moreover, the input sequence, with any binary alphabet may be matched to a desired output distribution with any arbitrary alphabet. Accordingly, probabilistic constellation shaping may be achieved over constellations of arbitrary size. In addition, relatively long codewords, may be encoded and decoded with the apparatus and method disclosed herein. Accordingly, for a fixed SNR a higher SE (more bits per symbol) can be achieved. Alternatively, for a fixed SE, a lower SNR may be sufficient. Moreover, the resulting SE may be finely tailored to a particular optical link SNR to provide data transmission rates that are higher than the low order modulation formats that would otherwise be employed for optical signals carried by such links.

An optical fiber comprising: (i) a multi-mode silica based glass core, said core having a 80-300 μm diameter and an index of refraction n₁; (ii) a cladding surrounding the core, said cladding having a thickness ≦20 μm and index of refraction index of refraction n₂<n₁, the cladding comprising (a) fluorine doped silica with relative index of refraction delta <0, or (b) a polymer with relative index of refraction delta <0; (iii) a protective coating, the protective coating having a Young's modulus greater than 700 MPa, a thickness ≦15 μm, and an index of refraction index of refraction n₃>n₂; and (iv) a permanent buffer.

Polymer-coated transmission media having water-blocking material embedded in the outer surface of the transmission media prevents water penetration into the transmission media and reduces the overall diameter of a cable made from the transmission media by eliminating a water-blocking tape layer in the cable. The outer surface of the transmission media is a polymer whose outer surface is embedded with a water-blocking material. The water-blocking material is applied before the polymer is cured. The transmission media may be any known type of optical media, which guides a light within the optical media. In various embodiments, optical fibers, buffered optical fibers and fiber ribbons are used as the transmission media.

The invention relates to a cascaded Mach-Zehnder interferometer based reconfigurable comb filter and a preparation method thereof. The filter comprises a planar lightwave circuit (PLC) chip, a first optical fiber array and a second optical fiber array, wherein the PLC chip comprises a silicon substrate, a silicon dioxide buffer layer is arranged on the silicon substrate, a waveguide is arranged on the silicon dioxide buffer layer, a coverage layer is arranged on the waveguide, and the waveguide comprises an input-stage Y branch, a first-length fixing arm, a second-length fixing arm, a first opening arm, a second opening arm, a third opening arm, a fourth opening arm, a first-stage 3dB coupler, a second-stage 3dB coupler and an output-stage 3dB coupler. The method comprises the steps of preparing the buffer layer and the waveguide on the silicon substrate so as to obtain a PLC chip portion, slicing and grinding the PLC chip portion, then, coupling the PLC chip portion with the optical fiber arrays, and finally, connecting corresponding optical fibers. The filter and the method have the advantages of reconfigurability, fine adjustable phase, flat-crest filtering and low-nonlinearity output.

Described are cable designs adapted for aerial installations wherein the cable comprises a bundle of multifiber tight buffer encasement units, with a conformal thin skin containment layer surrounding the bundle. The multifiber tight buffer encasement units have an acrylate compliant inner layer that protects the fiber and minimizes stress transfer to the fiber; and a hard, tough acrylate outer layer that provides crush resistance. The thin skin containment layer provides cable integrity with a minimum of added size and weight. The thin skin containment layer encasement is encased in an outer protective jacket.

Disclosed is a small-diameter polarization maintaining optical fiber, which relates to the field of special optical fibers. The small-diameter polarization maintaining optical fiber comprises a quartz optical fiber (5); the periphery thereof is provided with an inner coating (6) and an outer coating (8); the interior of the quartz optical fiber (5) is provided with an optical fiber core layer (1) and a quartz cladding (2); two stress zones (4) are arranged between the optical fiber core layer (1) and the quartz cladding (2); a buffer coating (7) is arranged between the inner coating (6) and the outer coating (8); the periphery of each stress zone (4) is provided with a buffer layer (3) which is concentric with the stress zone (4); when a working wavelength of a small-diameter polarization maintaining optical fiber is 1310 nm, the attenuation thereof reaches less than 0.5 dB/km, and the crosstalk reaches −35 dB/km; and when the working wavelength of the small-diameter polarization maintaining optical fiber is 1550 nm, the attenuation thereof reaches less than 0.4 dB/km, and the crosstalk reaches −30 dB/km. The optical fiber not only has excellent stability characteristics of attenuation and crosstalk, but also has the excellent stability characteristic of long-term operation, and can provide a better optical fiber ring for research on a high-precision optical fiber gyroscope, thereby laying the foundation for the development directions of miniaturization and high precision of the optical fiber gyroscope.

The invention discloses a high voltage and ultrahigh voltage flexible direct current transmission optical fiber composite extrusion insulation submarine cable. A water-resistant conductor is arranged at the center of the cable. A semiconductive wrapping belt, an extrusion inner shielding layer, an extrusion insulation layer, an extrusion outer shielding layer, a first buffer water-resistant layer, a second buffer water-resistant layer, a metal sleeve, an extrusion inner sheath, an extrusion molding steel wire and an extrusion outer sheath are sequentially wrapped outside the water-resistant conductor. Optical fibers are placed between the buffer water-resistant layers. The insulation layer overcomes the shortcoming of electric field distortion even breakdown caused by space charge accumulation of a traditional cable insulation material. A copper sleeve with good physical performances such as mechanical strength and fatigue strength is adopted to ensure safe reliable running. The submarine cable resolves the problem of heavy metal pollution caused by a lead sleeve utilized in a traditional submarine cable and prevents environment pollution caused by the fact that an asphalt wrapping plastic rope is coated on the surface of a bare steel wire of a traditional submarine cable to serve as a steel wire corrosion-resistant layer by extruding the extrusion molding steel wire and the extrusion outer sheath on the inner sheath.

Disclosed is a dry, semi-tight optical fiber unit that includes one or more optical fibers positioned within a buffer tube. A protective coating is provided upon the surface of the optical fibers, and an anti-adhesive coating is substantially bonded to the protective coating. One or more of these optical fiber units may be included in an optical cable. Also disclosed is a method for efficiently producing such an optical fiber unit.

The present invention relates to central loose optical-fiber cables. An exemplary optical-fiber cable includes a central buffer tube that encloses loose optical fibers. Stranded strength yarns surround the central buffer tube and the optical fibers positioned within the central buffer tube's annular space, and a cable jacket surrounds the stranded strength yarns.

At least one buffered optical fiber, and methods for manufacturing the same, including an optical fiber and a buffer layer. The buffer layer generally surrounds the optical fiber and has a low-shrink characteristic that preserves optical performance during, for example, temperature variations. In other embodiments, the at least one buffered optical fiber may be a fiber optic ribbon.