Abstract: Disclosed are multi-stage optical amplifiers that propagate higher-order mode (HOM) signals. One embodiment, among others, comprises a first segment of optical fiber in which a first HOM signal propagates, a second segment of optical fiber in which a second HOM signal propagates, and a mode converter that converts the first HOM signal into the second HOM signal.

Abstract: The present disclosure provides an approach to more efficiently amplify signals by matching either the gain materials or the pump profile with the signal profile for a higher-order mode (HOM) signal. By doing so, more efficient energy extraction is achieved.

Abstract: Embodiments of the invention include a connector system. The connector system includes a connector cover. The connector-cover has a cap to protect a connector from dust and water and an adapter attached to an optical fiber cable, which is configured to connect to the cap. The dimensions and configuration of the connector-cover allow it to be pulled through conventional conduit (i.e. a 90°-bent, 0.75 inch Schedule 40 conduit).

Abstract: The specification describes an optical fiber device for propagating and recompressing high energy, ultrashort pulses with minimal distortions due to nonlinearity. The device is based on propagation in a higher order mode (HOM) of a few-moded fiber. Coupling into the HOM may be accomplished using long-period gratings. Features of the HOM fiber mode that are useful for high quality pulse compression include large effective area, high dispersion and low dispersion slope. In a preferred case the long period gratings go through a turn-around point (TAP) at the wavelength of operation.

Abstract: Disclosed is a dispersion-compensating (DC) module [740] comprising a first length of DC optical fiber [10] in tandem with a second length of a standard singlemode optical fiber. The DC fiber is fabricated from silica glass and has a refractive index profile that includes a core region [51] surrounded by a cladding region [52] having a nominal refractive index n4. The core region includes a central core [511] having a nominal refractive index n1, a “trench” [512] surrounding the central core having a nominal refractive index n2, and a “ridge” [513] surrounding the trench having a nominal refractive index n3. A range of refractive index profiles has been found that provides relative dispersion slopes (RDS) that are greater than 0.012 nm−1 and figures of merit that are greater than 200 ps/(nm·dB).

Abstract: A hybrid strength member (300) for an optical cable (10) is made from dielectric materials, and provides excellent compressive and tensile properties within a single structure. The strength member includes two concentric layers of filamentary strands that are embedded in a thermoset material such as epoxy. The filamentary strands of the inner layer (310) primarily comprise aramid fibers, while the filamentary strands of the outer layer (320) primarily comprise glass fibers. A pair of strength members (300-1, 300-2) is embedded in a plastic jacket of the optical cable at diametrically opposite sides of a central core tube that contains a number of optical fibers. Each strength member includes a thin coating (330) of a relatively soft material (i.e., a hardness of less than 80D on the Shore durometer scale) to enhance its coupling to the plastic jacket.

Abstract: An optical cable tracing system is constructed using an optical/electrical (hybrid) cable 10 containing both optical and electrical transmission media. This cable provides desirably high bandwidth via optical fibers 15 while connection accuracy is provided via electrical wires 13, which are used to operate indicator lights 941 at one or both ends of the cable. A hybrid plug connector 300 terminates the cable at each end and includes a dielectric housing 20, 30 that encloses the optical fiber (glass or plastic), which extends through a front opening 21 in the housing. A single cantilever latch 22 is mounted on a top-side of the housing that is adapted to engage a mating jack receptacle 440 in a locking relationship. A conductor-holding apparatus is molded into the bottom side of the housing where it holds a number of insulated electrical conductors and metallic blade terminals 36 that pierce the insulation and make electrical contact with each of the conductors.

Abstract: An optical cable tracing system is constructed using an optical/electrical (hybrid) cable 10 containing both optical and electrical transmission media. This cable provides desirably high bandwidth via optical fibers 15 while connection accuracy is provided via electrical wires 13, which are used to operate indicator lights 941 at one or both ends of the cable. A hybrid plug connector 300 terminates the cable at each end and includes a dielectric housing 20, 30 that encloses the optical fiber (glass or plastic), which extends through a front opening 21 in the housing. A single cantilever latch 22 is mounted on a top-side of the housing that is adapted to engage a mating jack receptacle 440 in a locking relationship. A conductor-holding apparatus is molded into the bottom side of the housing where it holds a number of insulated electrical conductors and metallic blade terminals 36 that pierce the insulation and make electrical contact with each of the conductors.

Abstract: Disclosed is a dispersion-compensating (DC) optical fiber 10 that is designed to support the fundamental mode of radiation at 1550 nm. The DC fiber is fabricated from silica glass and has a refractive index profile that includes a core region 51 surrounded by a cladding region 52 having a nominal refractive index n4. The core region includes a central core 511 having a nominal refractive index n1, a “trench” 512 surrounding the central core having a nominal refractive index n2, and a “ridge” 513 surrounding the trench having a nominal refractive index n3. A range of refractive index profiles has been found that provides relative dispersion slopes (RDS) that are greater than 0.012 nm−1 and figures of merit that are greater than 200 ps/(nm·dB). The range is conveniently expressed in terms of index differences and radial dimensions: central core: radius=1.5±0.5 &mgr;m, and 0.015<n1−n4<0.035; trench: width=4.3±1.0 &mgr;m, and −0.

Abstract: Disclosed is a dispersion-compensating (DC) optical fiber 10 that is designed to support only the fundamental mode of radiation at 1550 nm. The DC fiber is fabricated from silica glass and has a refractive index profile that includes a core region 51 surrounded by a cladding region 52 having a nominal refractive index n4. The core region includes a central core 511 having a nominal refractive index n1, a “trench” 512 surrounding the central core having a nominal refractive index n2, and a “ridge” 513 surrounding the trench having a nominal refractive index n3. A range of refractive index profiles has been found that provides figures of merit that are greater than 300 ps/(nm·dB) and relative dispersion slopes that are greater than 0.01 nm−1. The range is conveniently expressed in terms of index differences and radial dimensions: central core: radius=1.5±0.5 &mgr;m, and 0.015<n1−n4<0.035; trench: width=3.5±1.0 &mgr;m, and −0.

Abstract: A high density optical connecting block 100 is mounted in a relatively thin, flat panel 10, and is constructed as an array of identical cells 110 that are linked together as a one-piece unit. The connecting block has a front-to-back depth that is greater than ten millimeters for imparting flexural rigidity to the panel. The array includes at least twelve cells that are arranged in two or more rows and two or more columns. Each cell has a front side that is shaped to receive and interlock with a duplex optical connector 50, and a back side that is shaped to receive and interlock with two simplex optical plugs 20. The duplex connector is a unifying structure that yokes a pair of simplex optical plugs 20-1, 20-2 into a duplex configuration.

Abstract: The present invention generally relates to the field of optical transmission and particularly to a method and an apparatus for controlling the optical power of an optical transmission signal in wavelength division multiplex optical transmission system (WDM system). It is known to add one additional channel to the optical transmission signal of WDM systems, for controlling the power of the optical transmission signal. The optical power of the control channel is controlled to keep the total optical power of the optical transmission signal constant, e.g., if a channel of the optical transmission signal fails, the optical power of the control channel is increased. To change the optical power of the control channel usually the injection current of a laser which generates the control channel is changed as the laser is operated in the continuous wave mode. This causes the disadvantage of cross talk which influences the optical transmission signal.

Abstract: An optical cable tracing system is constructed using an optical/electrical (hybrid) cable 10 containing both optical and electrical transmission media. This cable provides desirably high bandwidth via optical fibers 15 while connection accuracy is provided via electrical wires 13, which are used to operate indicator lights 941 at one or both ends of the cable. A hybrid plug connector 300 terminates the cable at each end and includes a dielectric housing 20, 30 that encloses the optical fiber (glass or plastic), which extends through a front opening 21 in the housing. A single cantilever latch 22 is mounted on a top-side of the housing that is adapted to engage a mating jack receptacle 440 in a locking relationship. A conductor-holding apparatus is molded into the bottom side of the housing where it holds a number of insulated electrical conductors and metallic blade terminals 36 that pierce the insulation and make electrical contact with each of the conductors.

Abstract: A high density optical connecting block 100 is mounted in a relatively thin, flat panel 10, and is constructed as an array of identical cells 110 that are linked together as a one-piece unit. The cells have a front-to-back depth that is greater than ten millimeters for imparting flexural rigidity to the panel. The array includes at least twelve cells that are arranged in two or more rows and two or more columns. Each cell has a front side that is shaped to receive and interlock with a duplex optical connector 50, and a back side that is shaped to receive and interlock with two simplex optical plugs 20. The duplex connector is a unifying structure that yokes a pair of simplex optical plugs 20-1, 20-2 into a duplex configuration.

Abstract: A method is disclosed for qualifying a multimode optical fiber 150 for bandwidth performance when used with a particular laser source. The method combines the modal power distribution (MPD) excited by a particular laser source with the differential mode delay (DMD) characteristic of the fiber. The DMD of the fiber is measured by injecting test pulses into one end of the fiber and detecting the resulting output pulse(s) at the other end. The test pulses are adapted to excite only a small number of the modes supported by the fiber. The test pulses are scanned across the core of the fiber at close intervals with the output pulse(s) stored at each radial position. A weighted sum of the output pulses is formed to determine a time-domain impulse response, where the weighting used corresponds to the MPD excited by the laser source. Bandwidth is then determined by standard methods for transforming the impulse response into the frequency domain.

Abstract: A optical fiber is disclosed that is suitable for use in a dispersion-compensated, optical communication system that is served by Erbium-doped fiber amplifiers. The fiber has a negative chromatic dispersion that is more negative than −0.8 ps/(nm-km) over the wavelength region 1530-1565 nm. and has a dispersion slope that is less than 0.05 ps/(nm2-km). This fiber exhibits an average optical transmission loss that is less than 0.21 dB/km; and its effective area exceeds 50 &mgr;m2, which renders it relatively insensitive to bending loss. The optical fiber includes a core of germanium-doped silica whose refractive index is n1, and a layer of cladding material that surrounds the core. The cladding comprises approximately pure silica, whose refractive index is n2. Between the core and the cladding, the fiber further includes first and second annular rings of doped silica. The first annular ring has a width of 4.5±1.5 microns, is doped with fluorine, and has a refractive index n3.

Abstract: A coaxial cable [10, 50] includes an inner conductor [11] that is separated from an outer conductor [13] by a layer of insulating material [12]. The outer conductor includes a thin sheet of metallic foil that envelops the insulating material and has a seam [14] that extends in the longitudinal direction of the cable. In a first embodiment, the insulated conductor is axially rotated (twisted) with respect to its own longitudinal axis. In a second embodiment, the outer conductor is wrapped around the layer of insulating material. In both embodiments, there is relative rotation between the insulated conductor and the outer conductor. This practice is referred to as relative insulated conductor rotation, and it significantly improves the structural return loss characteristics of a coaxial cable when the outer conductor includes an asymmetry, such as a seam, that extends in the longitudinal direction of the cable.

Abstract: A modular jack 200 includes a jack housing 220 with an opening 225 in its front end that is adapted to receive a modular plug 100. Within the opening there are a number of jack springs 215 for making electrical contact with metallic blades 120 that are installed in the plug. Variations in the actual position 211 where the plug blades make contact with the jack springs are reduced by the inclusion of a positioning member within the housing. This is extremely important in situations where the modular plug includes crosstalk compensation, since positional variations affect the amount of crosstalk compensation needed. In one embodiment, the positioning member comprises a cam 228 that engages a flexible latch 130 on the modular plug to create an axial force “F1” that pushes the plug toward a retaining surface 229 within the housing.

Abstract: An optical fiber [10] having protective coating materials [14, 15], which surround an elongated strand of glass [12], is designed for improved strippability. Preferably, the optical fiber includes two layers (primary and secondary) of radiation-cured polymeric materials surrounding the glass fiber. The primary layer has an equilibrium (in-situ) modulus that resides within the range 120 to 500 psi. Additionally, the primary coating has a pull-out force (adhesion) that is less than 1.2 pounds per centimeter of length (lb/cm), and preferably resides within the range 0.5 to 1.0 lb/cm. It has been found that by increasing the equilibrium modulus, delamination resistance is increased. This has allowed designers to decrease pull-out force while maintaining a suitable delamination resistance. As a result, coating materials can now be stripped away from a glass fiber with little or no residue.

Abstract: A high-capacity optical fiber network [100, 200] includes wavelength-division multiplexing (WDM) within the 1.4 micron (&mgr;m) wavelength region (i.e., 1335-1435 nm). Such a system includes optical fiber [130] whose peak loss in the 1.4 &mgr;m region is less than its loss at 1310 nm. The optical fiber has a zero dispersion wavelength (&lgr;0) at about 1310 nm, and linear dispersion between about 1.5 and 8.0 ps/nm-km within the 1.4 &mgr;m region. At least three WDM channels operate at 10 Gb/s in the 1.4 &mgr;m wavelength region and have a channel separation of 100 GHz. In one illustrative embodiment of the invention, a broadcast television channel, having amplitude modulated vestigial sideband modulation, simultaneously operates in the 1.3 &mgr;m region (i.e., 1285-1335 nm) and/or the 1.55 &mgr;m region (i.e., 1500-1600 nm). In another embodiment of the invention, 16 digital data channels are multiplexed together in the 1.55 &mgr;m region, each channel operating at about 2.5 Gb/s.