Abstract: A system may include a first DAS station, comprising a first plurality of interrogator units to launch a first plurality of DAS signals in a first direction, wherein a first interrogator unit is configured to launch a first DAS signal at a first interrogation rate and first wavelength, wherein a second interrogator unit is configured to launch a second DAS signal at a second wavelength and second interrogation rate, less than the first interrogation rate. The system may include a loopback array, comprising a plurality of loopbacks, arranged over a plurality of spans, wherein a first set of proximate loopbacks nearest to the first DAS station are configured to route back the first DAS signal to the first DAS station, and wherein a first set of intermediate loopbacks, located further from the first DAS station, are configured to route back the second DAS signal to the first DAS station.

Abstract: An optical communication system and method. The system includes a plurality of cable landing stations configured to be communicatively coupled using one or more optical communication cables in a peer-to-peer network for routing of one or more optical signals using one or more network elements. Each cable landing station includes a management device configured to determine one or more optical communication paths for routing optical signals, and a command/response optical device communicatively coupled to the management device for routing optical signals in accordance with the optical communication path. In response to receiving a request for routing at least one optical signal, the management device of each cable landing station is configured to determine at least one optical communication path for routing the optical signal in accordance with a topology map of the peer-to-peer network of the plurality of cable landing stations.

Abstract: A method and a system for transmission of optical signals. The system includes one or more first switching optical devices configured to switch transmission of one or more optical signals from one or more first fiber cores to one or more second fiber cores. It includes one or more second switching optical devices configured to pass-through transmission of one or more optical signals from one or more first fiber cores to one or more third fiber cores.

Abstract: Disclosed are a system and a method for configuring an optical transmission system. A process may include arranging a first ruggedized repeater on or in a first object or structure. A second ruggedized repeater may be arranged on or in a second object or structure different from the first object or structure. A third ruggedized repeater may be arranged on or in a third object or structure different from the first and second objects or structures, wherein: (i) a first distance between the first ruggedized repeater and the second ruggedized repeater and (ii) a second distance between the second ruggedized repeater and the third ruggedized repeater are equal or nearly equal and based on signal loss.

Abstract: A system and a method for monitoring an optical transmission path in an optical transmission system. The optical transmission system includes a sensing and interrogation unit and a plurality of sensing units positioned on the optical transmission path. An optical signal is transmitted to the plurality of sensing units for determining a status of one or more portions of an optical communication path. A plurality of reflected signals responsive to the optical signal are received. The plurality of reflected signals are transformed in at least one of: the frequency domain and the time domain. The status of one or more portions is determined using the transformed plurality of reflected signals.

Abstract: Techniques for improving gain equalization in C- and L-band (“C+L”) erbium-doped fiber amplifier (EDFAs) are provided. For example, the C- and L-band amplification sections of a C+L EDFA may be separated and configured in a parallel arrangement or a serial arrangement. For both the parallel and serial arrangements, the C- and L-band amplification sections may share a common gain flattening filter (GFF) or each amplification section may include and employ a separate GFF. Moreover, in some examples, an “interstage” L-band GFF may be located before or upstream of the L-band amplification section such that the L-band optical signal is gain-equalized or flattened prior to the L-band amplification section amplifying the L-band.

Abstract: A sensing system may include a distributed acoustic sensing (DAS) station to launch a DAS signal as an outbound DAS signal, as well as a plurality of DAS loopback assemblies, arranged along a plurality of spans. The plurality of DAS loopback assemblies may be arranged to separately process the outbound DAS signal, and return to the DAS station, the outbound DAS signal, as a return DAS signal that comprises a backscattered Rayleigh signal. As such, a given DAS loopback assembly of the plurality of DAS loopback assemblies may include an Erbium-Doped Fiber Amplifier (EDFA) that is arranged to compensate the loss from Rayleigh scattering of the DAS signal, and a filter device having an optical filtering function that is arranged to selectively send back just a sensing wavelength of the DAS signal.

Abstract: An undersea sensing system may include a first distributed acoustic sensing (DAS) station, comprising a first DAS transmitter and a first DAS receiver connected by an undersea optical communications cable. The first DAS transmitter is configured to launch a first outbound DAS signal in a first direction, over at least one sensing span of the optical communications cable. The DAS receiver is configured to receive a backscattered Rayleigh signal, based upon the first outbound DAS signal, wherein the first DAS signal is transmitted over a first D? fiber in a first half of the sensing span, and is transmitted over a first D+ fiber over a second half of the sensing span. The system further includes a second DAS station having a second DAS transmitter to launch a second outbound DAS signal in a second direction, opposite the first direction, over the at least one span.

Abstract: A sensing system. The sensing system may include a transmitter to launch an outbound optical signal, a clock to generate a clock signal, and a chirp subcarrier coupled to the clock and configured to generate a chirp. The sensing system may further include a code generator coupled to the clock and configured to generate a code; and an intensity modulator, arranged to modulate the outbound optical signal and coupled to receive an intensity modulator signal that is derived at least in part from the code generator.

Abstract: Disclosed is a cable with multimetallic conductor structure. In some embodiments, a method of forming an optical cable may include providing a buffer tube around a plurality of optical fibers, providing a plurality of layered strength members around the buffer tube, and forming a conductive conduit around the plurality of layered strength members. The conductive conduit may include a multimetallic strip of a first metal layer and a second metal layer and, if beneficial, further layers, wherein forming the conductive conduit comprises bending the multimetallic strip from a flat configuration to a cylindrical configuration, and/or applying a metal layer via an electrolytic or hot dip process. The method may further include forming an outer insulating jacket surrounding the conductive conduit.

Abstract: An undersea fiber optic cable architecture including a beach manhole (BMH) installed at a terrestrial site, a terrestrial station connected to the BMH by a terrestrial fiber optic cable, a first landing cable extending from the BMH into territorial waters adjacent the terrestrial site and connected to a first enhanced branching unit (EBU) located in the territorial waters, a second landing cable extending from the BMH into the territorial waters and connected to a second EBU located in the territorial waters, a recovery path cable connecting the first EBU to the second EBU, a first trunk cable extending from the first EBU into international waters, and a second trunk cable extending from the second EBU into the international waters.

Abstract: Disclosed herein are undersea optical cable connection assemblies and systems. In some embodiments, a retainer is operable to arrange a plurality of SCFs and a plurality of microsplints, the retainer including a main body having a first section and a second section. The retainer may further include a first channel and a second channel extending through the first section, wherein a first set of SCFs extend through the first channel, and wherein a second set of SCFs extend through the second channel. The retainer may further include a third channel and a fourth channel extending through the first section, wherein a first set of microsplints extends through the third channel, and wherein a second set of microsplints extends through the fourth channel. A third set of microsplints extends through the third channel, wherein the first and third sets of microsplints are separated from one another by a padding layer.

Abstract: An optical communication system and a method. The system includes a distributed acoustic sensing (DAS) interrogation unit. The DAS interrogation unit is configured to generate one or more optical signals for determining a status of one or more portions of an optical communication path, modulate one or more optical signals using one or more measurement pulses and generate one or more modulated optical signals, and transmit one or more modulated optical signals to the one or more portions of the optical communication path. The status of one or more portions of the optical communication path is determined based on one or more reflected signals reflected by one or more portions of the optical communication path in response to one or more modulated optical signals.

Abstract: An apparatus and a method for transmission of optical signals. The apparatus includes a bidirectional amplification device communicatively coupled between a first communication terminal and a second communication terminal. The first and second communication terminals are communicatively coupled using an optical communication link. The bidirectional amplification device is configured to transmit and amplify one or more optical sensing signals transmitted in either direction between the first communication terminal and the second communication terminal. The optical sensing signals indicate a status of one or more portions of the optical communication link.

Abstract: A fiber amplifier assembly may include an input fiber end, and an output fiber end, opposite to the input fiber end. The fiber amplifier assembly may further include a plurality of optical fiber segments, comprising at least one doped optical fiber segment, and arranged in a linear assembly, the plurality of optical fiber segments being mutually arranged to define an optical path between the input fiber end and the output fiber end. The fiber amplifier assembly may also include a reflector assembly, comprising a first set of reflectors arranged at the input fiber end, and a second set of reflectors, arranged at the output fiber end, wherein the first set of reflectors and second set of reflectors together with the plurality of optical fiber segments conduct a light signal traveling through the optical path between a pair of optical fibers.

Abstract: Disclosed are undersea cables having a high fiber count and low electrical resistance. In some embodiments, an optical cable includes a hollow buffer tube having a plurality of optical fibers therein, wherein the hollow buffer tube includes inner and outer buffer surfaces, and wherein the outer buffer surface of the hollow buffer tube defines an outer diameter. The optical cable may further include a first plurality of layered strength members surrounding the hollow buffer tube, and a conductor surrounding the first plurality of layered strength members. The optical cable may further include an outer jacket surrounding the conductor, wherein the outer jacket includes inner and outer jacket surfaces, wherein the outer jacket defines an outer diameter of the outer jacket, and wherein the outer diameter of the outer jacket is equal to or less than five times the outer diameter of the hollow buffer tube.

Abstract: Techniques for extending distributed acoustic sensing (DAS) range in undersea optical cables are provided. For example, DAS range can be extended by transmitting and amplifying a DAS signal along multiple spans of a first optical fiber, routing or bypassing the DAS signal from the first optical fiber to a second optical fiber different from the first fiber via a high-loss loopback architecture, and returning and amplifying the DAS signal along the same multiple spans back to a DAS device. The DAS device may then receive and process the DAS signal to detect any changes in the DAS environment. The loopback configuration may be based on different types of loopback architecture.

Abstract: An optical pump unit may include a line voltage transistor, coupled between an input side and an output side of the optical pump unit. The optical pump may further include a DC-to-DC converter, having an input side coupled to the line voltage transistor; an optical pump assembly, coupled to an output side of the DC-to-DC converter; a current control assembly, coupled to the optical pump assembly; a throttle back control assembly, having an output coupled to the current control assembly, and a current/voltage sensor, to monitor a line current and voltage drop in the optical repeater, and being coupled to an input of the throttle back control assembly. As such, the throttle back control assembly may be configured to send a signal to the current control assembly to reduce a power at the optical pump assembly when a decrease in line current or voltage drop takes place.

Abstract: A method and a system for transmission of optical signals. One or more first and second multi-core optical components are coupled to all fiber cores in a multi-core fiber. An erbium-doped fiber amplifier (EDFA) optical component is coupled to all fiber cores in the multi-core fiber and includes a plurality of EDFAs. Each fiber core is coupled to an EDFA. The EDFA optical component is coupled to all fiber cores between the first and second multi-core optical components. First multi-core components are coupled at an input to a first portion of fiber cores and provide first functions, and are coupled at an output from a second portion of fiber cores and provide second functions. Second multi-core components are coupled at an output from the first portion of fiber cores and provide second functions, and are coupled to an input to the second portion of fiber cores and provide first functions.

Abstract: Disclosed is a joint assembly for an optical cable. In some embodiments, the joint assembly may include a termination assembly adjacent to a joint, enclosed in a boot assembly, wherein the termination assembly electrically connects, or grounds, a first optical cable and a second optical cable. The termination assembly may include a heat shrink layer surrounding a core of the optical cable, wherein the core comprises a plurality of fibers surrounded by a plurality of strength members, and a first tape layer formed around the heat shrink layer. The termination assembly may further include a non-metallic gripping layer formed over the first tape layer, a second tape layer formed over the non-metallic gripping layer, and a non-metallic material formed over the second tape layer.