Flame retardant communications cables may include at least one transmission media and at least one other component, such as a separator, buffer tube, jacket, shield layer, or wrap. The at least one other component may include a body portion, and at least one cavity formed in the body portion in which an extinguishant is positioned. Additionally, the at least one transmission media is not positioned within the at least one cavity.

An optical fiber cable comprises a cable core including at least one optical transmission element to transfer light, and a cable jacket surrounding the cable core. The cable jacket is embodied as a multilayered structure having a first sheath layer and at least a second sheath layer being surrounded by the first sheath layer. The material of the first and the second sheath layer is halogen free. The material of the first sheath layer and the material of the second sheath layer have a different flame retardant additive providing different flame retardant mechanisms.

This disclosure is directed to lighting diffusing fibers (LDFs) having a flame retardant coating thereon. The LDFs comprise a glass RAL fiber core having a primary polymer coating of a clear, colorless polymeric material having an index of refraction less than that of the glass fiber core and a flame retardant coating applied over the primary coating. The flame retardant coating consist of approximately 35-85 wt. % UV curable polymer forming monomers and 15-65 wt. % of an inorganic, halogen free filler, along with at least one photoinitiator and an antioxidant. In an embodiment phosphor-containing polymer layer can be applied between the primary coating and the flame retardant coating. In another embodiment the phosphor can be added to the flame retardant coating.

A fiber optic cable includes a jacket forming a cavity therein, the jacket having an indentation on the exterior thereof that forms a ridge extending into the cavity along the length of the jacket; and a stack of fiber optic ribbons located in the cavity, each ribbon having a plurality of optical fibers arranged side-by-side with one another and coupled to one another in a common matrix, wherein corners of the ribbon stack pass by the ridge at intermittent locations along the length of the jacket, and wherein interaction between the ridge and the ribbon stack facilitates coupling of the ribbon stack to the jacket.

Double-clad optical fibers with polymer outer coatings are used in fiber amplifiers and fiber lasers to guide and amplify light. As the optical power increases, the optical fibers must dissipate more heat. Unfortunately, it is difficult to dissipate heat through a polymer cladding, especially at high altitude, without introducing phase noise in the optical signal. To overcome this problem, the inventors have realized metallized polymer-clad optical fibers with superior heat dissipation characteristics than conventional polymer-clad optical fibers. An example metallized polymer-clad optical fiber includes a thin chrome layer that is vacuum-deposited onto the polymer cladding at low temperature, then electroplated with a thicker copper layer. In operation, the copper layer dissipates heat from within the fiber's core and claddings via a heatsink, enabling the fiber to guide and amplify high-power optical signals at high altitude.

Provided is an optical fiber cable having excellent flame retardancy, long-term heat resistance and mechanical characteristics. An optical fiber cable according to the present invention comprises an optical fiber and a cladding layer that is provided on the outer circumference of the optical fiber. The cladding layer contains a chlorinated polyolefin resin (A) and a polyolefin resin (B).

A fiber optic sensor to determine a property in an environment with a temperature exceeding 150 degrees Celsius includes a light source to emit broadband light, an etendue of the light source being less than 1000 square micro meter-steradians (μm.sup.2 sr), and an optical fiber to carry incident light based on the broadband light and a reflection resulting from the incident light. A photodetector detects a resultant light based on the reflection and outputs an electrical signal, and a processor processes the electrical signal from the photodetector to determine the property.

Embodiments include an optical fiber cable comprising a length extending between a first end and a second end, a central cooling tube, a plurality of optical fibers disposed radially around the cooling tube, each optical fiber comprising a fiber core and a cladding disposed around the fiber core, an outer protective cover, and an inner thermal filler disposed between the outer protective cover and the central cooling tube and surrounding each of the optical fibers, wherein each of the central cooling tube, the outer protective cover, the inner thermal filler, and the plurality of optical fibers extend the length of the cable. Various systems and methods for removing imperfections from individual optical fibers and for distributing power across long distances using the optical fiber cable are also provided.

An optical fiber drop cable. The optical fiber drop cable includes at least one optical fiber and at least one inner tensile element wound around the at least one optical fiber having a laylength of at least 200 mm. The optical fiber drop cable also includes an interior jacket disposed around the at least one inner tensile element and an exterior jacket having an inner surface and an outer surface. The optical fiber drop cable further includes at least one outer tensile element disposed between the interior jacket and the outer surface of the exterior jacket. Each of the at least one outer tensile element has a laylength of at least 1 m. The exterior jacket includes at least one polyolefin, at least one thermoplastic elastomer, and at least one high aspect ratio inorganic filler. The exterior jacket has an averaged coefficient of thermal expansion of no more than 120(10.sup.−6) m/mK.

An optical fiber cable including a central strength member extending along a longitudinal axis of the optical fiber cable and a plurality of buffer tubes that are wound around the central strength member. Each of the plurality of buffer tubes includes a first material having a modulus of elasticity of at most 600 MPa at room temperature and a peak heat release rate (PHRR) of at most 300 kW/m.sup.2 as measured according to ASTM E1354. A cable jacket is disposed circumferentially around the plurality of buffer tubes and extends along the longitudinal axis.