A method (1200) for noise loading an optical channel, comprising: allocating (1201) a 5 plurality of wavelength slots of an available spectrum in an optical fibre as comprised in traffic channels or noise loaded channels, wherein each noise loaded channel comprises a noise loaded wavelength slot and a monitoring wavelength slot for receiving data signals. A system (101) for noise loading is also disclosed.
H04B 10/079 - Arrangements for monitoring or testing transmission systemsArrangements for fault measurement of transmission systems using an in-service signal using measurements of the data signal
H04J 14/02 - Wavelength-division multiplex systems
H04Q 11/00 - Selecting arrangements for multiplex systems
2.
OPTICAL AMPLIFIERS THAT SUPPORT GAIN CLAMPING AND OPTIONALLY POWER LOADING
An apparatus includes an optical amplifier configured to receive an input opticalsignal and generate an amplified output optical signal. The optical amplifier includesmultiple amplifier stages including at least a first amplifier stage and a secondamplifier stage. The apparatus also includes a gain clamp configured to accumulateoptical power from the first amplifier stage after an optical power level of the input optical signal drops and provide a first portion of the accumulated optical power to thefirst amplifier stage to clamp a gain applied by the first amplifier stage. The gainclamp is also configured to provide a second portion of the accumulated optical powerto the second amplifier stage to adjust a gain applied by the second amplifier stage.The second amplifier stage is configured to amplify the second portion of the accumulated optical power.
H04B 10/079 - Arrangements for monitoring or testing transmission systemsArrangements for fault measurement of transmission systems using an in-service signal using measurements of the data signal
3.
Submarine optical system with free space optical add/drop multiplexer
A common component assembly is provided for a cable joint for joining a first submarine optical cable and a second submarine optical cable. The assembly includes a first end face including a first opening and a first flange for connection to a first cable termination unit of an undersea optical cable joint. The assembly also includes a second end face including a second opening and a second flange for connection to a second cable termination unit of an undersea optical cable joint. The assembly further includes a fiber tray connecting the first end face to the second end face. In addition, the assembly includes an optical assembly connected to a first side of the fiber tray. The optical assembly includes a free space optical add/drop multiplexer.
G02B 6/293 - Optical coupling means having data bus means, i.e. plural waveguides interconnected and providing an inherently bidirectional system by mixing and splitting signals with wavelength selective means
G02B 6/38 - Mechanical coupling means having fibre to fibre mating means
G02B 6/44 - Mechanical structures for providing tensile strength and external protection for fibres, e.g. optical transmission cables
H04B 10/25 - Arrangements specific to fibre transmission
H04B 10/80 - Optical aspects relating to the use of optical transmission for specific applications, not provided for in groups , e.g. optical power feeding or optical transmission through water
H04J 14/02 - Wavelength-division multiplex systems
An optical repeater is disclosed, comprising: an optical input port for receiving an input optical signal; an optical output port for transmitting an output optical signal; electronics comprising an amplifier configured to increase a signal level of the optical signal between the input port and the output port; a voltage regulator configured to provide a variable voltage power supply to the electronics, and optionally comprising a local or external controller configured to determine a supply voltage in response to demand and to control the voltage regulator to provide the supply voltage.
H04B 10/80 - Optical aspects relating to the use of optical transmission for specific applications, not provided for in groups , e.g. optical power feeding or optical transmission through water
An apparatus includes an optical amplifier configured to receive an input optical signal and generate an amplified output optical signal. The optical amplifier includes multiple amplifier stages including at least a first amplifier stage and a second amplifier stage. The apparatus also includes a gain clamp configured to accumulate optical power from the first amplifier stage after an optical power level of the input optical signal drops and provide a first portion of the accumulated optical power to the first amplifier stage to clamp a gain applied by the first amplifier stage. The gain clamp is also configured to provide a second portion of the accumulated optical power to the second amplifier stage to adjust a gain applied by the second amplifier stage. The second amplifier stage is configured to amplify the second portion of the accumulated optical power.
H04B 10/079 - Arrangements for monitoring or testing transmission systemsArrangements for fault measurement of transmission systems using an in-service signal using measurements of the data signal
H04J 14/02 - Wavelength-division multiplex systems
H04B 10/80 - Optical aspects relating to the use of optical transmission for specific applications, not provided for in groups , e.g. optical power feeding or optical transmission through water
An optical communications apparatus is configured to be connected to first, second, and third optical cables. In a branch connecting configuration, a branch optical path is enabled so that (i) signal wavelengths received over the first cable are routed to the third cable and (ii) signal wavelengths received over the third cable are routed to the second cable. The signal wavelengths received over the third cable include at least one of the signal wavelengths routed from the first cable to the third cable and returned via a loop connection at a distal portion of the third cable. In a bypass configuration, a connection via the branch optical path to the distal portion of the third cable is bypassed so that the signal wavelengths received over the first cable are routed to the second cable without first being routed through the distal portion of the third cable.
G02F 1/00 - Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulatingNon-linear optics
H04B 10/038 - Arrangements for fault recovery using bypasses
G02B 6/35 - Optical coupling means having switching means
H04J 14/02 - Wavelength-division multiplex systems
H04B 10/25 - Arrangements specific to fibre transmission
H04B 10/80 - Optical aspects relating to the use of optical transmission for specific applications, not provided for in groups , e.g. optical power feeding or optical transmission through water
H04Q 11/00 - Selecting arrangements for multiplex systems
A common component assembly (10) is provided, for a cable joint for joining a first submarine optical cable and a second submarine optical cable. The assembly comprises: a first end face (71) comprising a first opening (73) and a first flange (72) for connection to a first cable termination unit (12) of an undersea optical cable joint; a second end face (81) comprising a second opening (83) and a second flange (82) for connection to a second cable termination unit (12) of an undersea optical cable joint; a fibre tray (85) connecting the first end face (71) to the second end face (81); and an optical assembly (185) connected to a first side of the fibre tray (85), the optical assembly (185) comprising a free space optical add/drop multiplexer.
H04J 14/02 - Wavelength-division multiplex systems
G02B 6/293 - Optical coupling means having data bus means, i.e. plural waveguides interconnected and providing an inherently bidirectional system by mixing and splitting signals with wavelength selective means
G02B 6/38 - Mechanical coupling means having fibre to fibre mating means
An optical repeater (200) is disclosed, comprising: an optical input port for receiving an input optical signal; an optical output port for transmitting an output optical signal; electronics (202) comprising an amplifier configured to increase a signal level of the optical signal between the input port and the output port; a voltage regulator (220) configured to provide a variable voltage power supply to the electronics (202), and optionally comprising a local or external controller (230) configured to determine a supply voltage in response to demand and to control the voltage regulator (220) to provide the supply voltage.
An apparatus includes a first optical coupler configured to duplicate an optical signal carried by a first cable in a second cable and a third cable. The apparatus also includes a second optical coupler configured to combine an optical signal carried by the second cable and an optical signal carried by the third cable in the first cable. The apparatus further includes an electrical switch configured to selectively connect electrical conductors of the first, second, and third cables.
H04B 10/00 - Transmission systems employing electromagnetic waves other than radio-waves, e.g. infrared, visible or ultraviolet light, or employing corpuscular radiation, e.g. quantum communication
H04B 10/80 - Optical aspects relating to the use of optical transmission for specific applications, not provided for in groups , e.g. optical power feeding or optical transmission through water
G02B 6/44 - Mechanical structures for providing tensile strength and external protection for fibres, e.g. optical transmission cables
H04B 10/032 - Arrangements for fault recovery using working and protection systems
10.
Integrated signal loss detection in Raman amplified fiber spans or other fiber spans
An apparatus includes multiple ports configured to be coupled to multiple optical fibers and to transmit first optical signals and receive second optical signals over the optical fibers. The apparatus also includes a signal source configured to generate a first additional optical signal for inclusion with the first optical signals. The apparatus further includes a signal detector configured to detect a second additional optical signal included with the second optical signals. In addition, the apparatus includes a switch configured to selectively couple the signal source to one of the ports. The switch is configured to couple the signal source to different ones of the ports in different configurations of the switch.
H01S 3/00 - Lasers, i.e. devices using stimulated emission of electromagnetic radiation in the infrared, visible or ultraviolet wave range
H04B 10/291 - Repeaters in which processing or amplification is carried out without conversion of the main signal from optical form
H04B 10/2537 - Arrangements specific to fibre transmission for the reduction or elimination of distortion or dispersion due to scattering processes, e.g. Raman or Brillouin scattering
H04B 10/077 - Arrangements for monitoring or testing transmission systemsArrangements for fault measurement of transmission systems using an in-service signal using a supervisory or additional signal
G02B 6/35 - Optical coupling means having switching means
H01S 3/094 - Processes or apparatus for excitation, e.g. pumping using optical pumping by coherent light
H01S 3/30 - Lasers, i.e. devices using stimulated emission of electromagnetic radiation in the infrared, visible or ultraviolet wave range using scattering effects, e.g. stimulated Brillouin or Raman effects
11.
INTEGRATED SIGNAL LOSS DETECTION IN RAMAN AMPLIFIED FIBER SPANS OR OTHER FIBER SPANS
An apparatus (100) includes multiple ports (102-108) configured to be coupled to multiple optical fibers (110-112) and to transmit first optical signals and receive second optical signals over the optical fibers (110-112). The apparatus also includes a signal source (118) configured to generate a first additional optical signal for inclusion with the first optical signals. The apparatus further includes a signal detector (120) configured to detect a second additional optical signal included with the second optical signals. In addition, the apparatus (100) includes a switch (122) configured to selectively couple the signal source (118) to one of the ports (102, 106). The switch (122) is configured to couple the signal source (118) to different ones of the ports (102, 106) in different configurations of the switch (122).
H04B 10/077 - Arrangements for monitoring or testing transmission systemsArrangements for fault measurement of transmission systems using an in-service signal using a supervisory or additional signal
H04B 10/2537 - Arrangements specific to fibre transmission for the reduction or elimination of distortion or dispersion due to scattering processes, e.g. Raman or Brillouin scattering
H04B 10/291 - Repeaters in which processing or amplification is carried out without conversion of the main signal from optical form
An optical communications apparatus includes a subsea cable, first and second landing stations, a splitter/combiner unit connected to an end of the subsea cable, and first and second legs connecting the splitter/combiner unit to the first and second landing stations, respectively. Each of the subsea cable and first and second legs includes an optical fiber configured to carry optical communications and an electrical conductor configured to carry electrical power. The splitter/combiner unit is configured to duplicate optical signals carried by the subsea cable in both the first and second legs. The first and second legs are configured to provide redundant electrical power connections to the subsea cable via the splitter/combiner unit.
H04B 10/00 - Transmission systems employing electromagnetic waves other than radio-waves, e.g. infrared, visible or ultraviolet light, or employing corpuscular radiation, e.g. quantum communication
H04B 10/80 - Optical aspects relating to the use of optical transmission for specific applications, not provided for in groups , e.g. optical power feeding or optical transmission through water
G02B 6/44 - Mechanical structures for providing tensile strength and external protection for fibres, e.g. optical transmission cables
H04B 10/032 - Arrangements for fault recovery using working and protection systems
An optical communications apparatus includes a branching unit and a switching module. The branching unit is configured to be connected to first, second, and third optical cables each including an optical fiber. The branching unit includes a branch optical path configured to route a fixed pre-determined range of wavelengths that are input to the branching unit from the optical fiber of the first cable to the optical fiber of the third cable. The switching module includes at least one optical switch having a bypass configuration and a branch connecting configuration. In the bypass configuration, a connection via the branch optical path to a distal portion of the third cable is bypassed. In the branch connecting configuration, the branch optical path is enabled so that the pre-determined range of wavelengths that are input to the branching unit are routed to the optical fiber of the distal portion of the third cable.
G02F 1/00 - Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulatingNon-linear optics
H04B 10/038 - Arrangements for fault recovery using bypasses
G02B 6/35 - Optical coupling means having switching means
H04J 14/02 - Wavelength-division multiplex systems
H04B 10/25 - Arrangements specific to fibre transmission
H04B 10/80 - Optical aspects relating to the use of optical transmission for specific applications, not provided for in groups , e.g. optical power feeding or optical transmission through water
H04Q 11/00 - Selecting arrangements for multiplex systems
A system includes (i) an optical link including multiple spans of optical fiber and multiple network elements and (ii) at least one switch configured to reverse a direction that at least one of the network elements communicates over the optical link.
An apparatus includes a remote optically pumped amplifier (ROPA). The ROPA includes a bypass filter configured to receive an optical signal and first pump power and to separate the optical signal and the first pump power. The ROPA also includes an amplifier configured to receive the optical signal from the bypass filter and to amplify the optical signal. The ROPA further includes an optical combiner/multiplexer configured to receive the first pump power from the bypass filter, receive at least second and third pump powers, combine at least two of the first, second and third pump powers, and provide different pump powers or combinations of pump powers to different locations within the ROPA to feed the amplifier.
H01S 3/30 - Lasers, i.e. devices using stimulated emission of electromagnetic radiation in the infrared, visible or ultraviolet wave range using scattering effects, e.g. stimulated Brillouin or Raman effects
A submarine optical repeater includes a submarine amplifier module, which further includes a pumping laser module and an optical detector module. The pumping laser module generates optical amplifications within an optical cable, and, in the case of a fault in the optical cable, the optical detector module detects at least one characteristic of an optical signal caused by the fault in the optical cable. This configuration then identifies a particular signal characteristic that indicates a fault within the optical cable.
H04B 10/071 - Arrangements for monitoring or testing transmission systemsArrangements for fault measurement of transmission systems using a reflected signal, e.g. using optical time domain reflectometers [OTDR]
H04B 10/073 - Arrangements for monitoring or testing transmission systemsArrangements for fault measurement of transmission systems using an out-of-service signal
H04B 10/80 - Optical aspects relating to the use of optical transmission for specific applications, not provided for in groups , e.g. optical power feeding or optical transmission through water
H04B 10/077 - Arrangements for monitoring or testing transmission systemsArrangements for fault measurement of transmission systems using an in-service signal using a supervisory or additional signal
A method and apparatus for time domain reflectometry. The method comprises: providing a source optical signal having a first frequency (f1); encoding and transmitting a first Golay code test signal and then a second complementary Golay code test signal along an optical fibre, wherein encoding the first and second Golay code test signals comprises using a frequency modulator (203) on a first portion of the source optical signal such that one of the states of the Golay code is encoded as the first frequency (f1), and another state of the Golay code is encoded as a second frequency (f2), the second frequency (f2) being produced by shifting the frequency of the optical signal from the first frequency (f1) to the second frequency (f2); detecting reflections of the first and second Golay code test signals that are mixed with a second portion of the source optical signal at a heterodyne detector (206) to produce a first and second detected reflection signal, respectively corresponding with reflections of the first and second Golay code test signals; processing data (rA(t), rB(t)) derived from the first and second detected reflection signal to approximate reflections (h(t)) from the optical fibre in response to a delta function test signal.
An optical communications apparatus (200), comprising: a branching unit (150) for connecting a first, second and third optical cable (110, 120, 130), each of the first, second and third optical cables comprising an optical fibre, the branching unit (150) comprising a branch optical path arranged to route a fixed pre-determined range of signal wavelengths (161, 162) that are input to the branching unit (150) from the optical fibre of the first cable (110) to the optical fibre of the third optical cable (130); a switching module (210) comprising at least one optical switch, the at least one optical switch having a bypass configuration in which a connection via the branch optical path to a distal portion of the third optical cable (130) is bypassed, so that all signal wavelengths (161, 162) input to the branching unit ( 150) from the optical fibre of the first cable (110) are routed to the optical fibre of the second optical cable (120) without first being routed through the connection to the distal portion of the third optical cable (130), and a branch connecting configuration in which the branch optical path is enabled so that a fixed pre-determined range of signal wavelengths (161, 162) that are input to the branching unit (150) from the optical fibre of the first cable (110) are routed to the optical fibre of the distal portion of the third optical cable (130).
An optical communications apparatus (100), comprising: a subsea cable (105); a first and second landing station (151, 152), a splitter/combiner unit (110) connected to an end of the subsea cable (105), first and second legs (101, 102) connecting the splitter/combiner unit (110) to the first and second landing station (151, 152) respectively. Each of the subsea cable (105) and first and second legs (101, 102) comprise an optical fibre for carrying optical communications and an electrical conductor for carrying electrical power. The splitter/combiner unit (110) is operable to duplicate optical signals carried by the subsea cable (105) in both the first and second legs (101, 102). The first leg (101) and second leg (102) are configured to provide redundant electrical power connections to the subsea cable (105) via the splitter/combiner unit (110).
H04B 10/80 - Optical aspects relating to the use of optical transmission for specific applications, not provided for in groups , e.g. optical power feeding or optical transmission through water
A system comprising: an optical link comprising multiple spans of optical fiber (130) and multiple network elements (310a, 310b...310n); and at least one switch (400a, 400b...400n) configured to reverse a direction that at least one of the network elements (310a, 310b...310n) communicates over the optical link.
An apparatus includes bidirectional communication equipment (A) for communicating information along optical fibers (AB, CA), wherein the bidirectional communications equipment (A) is configured to provide a first unidirectional communication link from the equipment (A) to a first location (B) and a second unidirectional communication link to the equipment (A) from a different second location (C).
An apparatus includes a remote optically pumped amplifier (ROPA) (110, 112, 130, 132, 200, 300, 400, 500, 600, 700, 800, 900, 1014, 1018, 1308a-1308m). The ROPA includes a bypass filter (204, 304, 804a, 804b, 904a, 904b, 1104, 1204a, 1204b) configured to receive an optical signal and first pump power and to separate the optical signal and the first pump power. The ROPA also includes an amplifier (206, 306, 806a, 806b, 906a, 906b, 1106, 1206a, 1206b) configured to receive the optical signal from the bypass filter and to amplify the optical signal. The ROPA further includes an optical combiner/multiplexer (208, 308, 402-404, 502-504, 602-604, 702-704, 808, 908, 1102c and 1120) configured to receive the first pump power from the bypass filter, receive at least second and third pump powers, combine at least two of the first, second and third pump powers, and provide different pump powers or combinations of pump powers to different locations within the ROPA to feed the amplifier.
An apparatus includes a remote optically pumped amplifier (ROPA). The ROPA includes a bypass filter configured to receive an optical signal and first pump power and to separate the optical signal and the first pump power. The ROPA also includes an amplifier configured to receive the optical signal from the bypass filter and to amplify the optical signal. The ROPA further includes an optical combiner/multiplexer configured to receive the first pump power from the bypass filter, receive at least second and third pump powers, combine at least two of the first, second and third pump powers, and provide different pump powers or combinations of pump powers to different locations within the ROPA to feed the amplifier.
An optical communication link that includes two nodes interconnected by an optical channel that comprises optical fiber(s), and that is used to communicate an optical signal comprising multiple optical signal wavelengths. The first node provides an optical signal onto the optical channel towards the second node, or receives an optical signal from the optical channel from the second node. A Raman pump provides Raman pump power into the optical fiber of the optical channel to thereby perform Raman amplification of the optical signal in the optical fiber. The second node determines a quality measurement of at least of optical wavelength signals transmitted by the first node to the second node. The second node also transmits information from the quality measurement back to the first node. A controller at the first node controls at least one parameter of the Raman pump in response to this transmitted information.
H04B 10/079 - Arrangements for monitoring or testing transmission systemsArrangements for fault measurement of transmission systems using an in-service signal using measurements of the data signal
H04B 10/25 - Arrangements specific to fibre transmission
H04J 14/02 - Wavelength-division multiplex systems
H04B 10/077 - Arrangements for monitoring or testing transmission systemsArrangements for fault measurement of transmission systems using an in-service signal using a supervisory or additional signal
H04B 10/291 - Repeaters in which processing or amplification is carried out without conversion of the main signal from optical form
H01S 3/13 - Stabilisation of laser output parameters, e.g. frequency or amplitude
H01S 3/094 - Processes or apparatus for excitation, e.g. pumping using optical pumping by coherent light
H01S 3/30 - Lasers, i.e. devices using stimulated emission of electromagnetic radiation in the infrared, visible or ultraviolet wave range using scattering effects, e.g. stimulated Brillouin or Raman effects
25.
Multi-span optical communications link having remote optically pumped amplifier
A remote optically pumped amplifier in a multi-span optical communications link. A backwards Raman pump module performs backwards Raman amplification in an optical communications span that contains the remote optically pumped amplifier. A residual amount of backwards Raman pump power is then used to power the remote optically pumped amplifier. The remote optically pumped amplifier may be located 40 to 120 kilometers in optical distance from the backwards Raman pump module such that at least three milliwatts of residual Raman pump power is received by the remote optically pumped amplifier. The Raman pump module may be a multi-pump Raman pump module. A controller controls pump power provided by at least one of the pumps of the backwards Raman pump module, so as to at least partially compensate for optical signal strength versus wavelength variation introduced by the remote optically pumped amplifier and the backwards Raman pump module.
H01S 3/30 - Lasers, i.e. devices using stimulated emission of electromagnetic radiation in the infrared, visible or ultraviolet wave range using scattering effects, e.g. stimulated Brillouin or Raman effects
A submarine optical repeater includes a submarine amplifier module, which further includes a pumping laser module and an optical detector module. The pumping laser module generates optical amplifications within an optical cable, and, in the case of a fault in the optical cable, the optical detector module detects at least one characteristic of an optical signal caused by the fault in the optical cable. This configuration then identifies a particular signal characteristic that indicates a fault within the optical cable.
H04B 10/071 - Arrangements for monitoring or testing transmission systemsArrangements for fault measurement of transmission systems using a reflected signal, e.g. using optical time domain reflectometers [OTDR]
H04B 10/80 - Optical aspects relating to the use of optical transmission for specific applications, not provided for in groups , e.g. optical power feeding or optical transmission through water
H04B 10/073 - Arrangements for monitoring or testing transmission systemsArrangements for fault measurement of transmission systems using an out-of-service signal
H01S 3/09 - Processes or apparatus for excitation, e.g. pumping
H04B 10/077 - Arrangements for monitoring or testing transmission systemsArrangements for fault measurement of transmission systems using an in-service signal using a supervisory or additional signal
27.
Optical repeater amplifier insertion and removal technology
A repeater amplifier assembly that includes at least two chassis containing optics and electronics. The chassis are connected with a size-adjustment mechanism that can adjust a size of the repeater amplifier assembly by reversibly adjusting the positions of the chassis with respect to each other. To insert the repeater amplifier assembly into a repeater housing, the repeater amplifier assembly is accessed in a contracted position. The amplifier is inserted into the housing, and then a control of the size adjustment mechanism is actuated to urge the chassis outwards until the chassis push against the repeater housing. To remove the repeater amplifier assembly from the repeater housing, the control is actuated to cause the size adjustment mechanism to pull the chassis inwards with respect to each other until the chassis no longer push against the repeater housing. The repeater amplifier assembly may then be freely removed from the repeater housing.
The system-level control of a repeatered optical communications system. In a repeatered optical communications system, two terminals are optically coupled via an optical communications span having one or more repeaters. One of the terminals may perform the control by monitoring quality metrics of optical signals received over the communication span. Based on this monitoring, certain adjustments are determined to be performed, and the repeater controllers of the respective optical repeaters are instructed to perform the adjustments. In some case, the optical repeater adjustments cannot be made without impacting the performance of the optical signals traveling in the opposite direction. In that case, the system-level control uses monitored quality metrics from both terminals to determine the adjustments to be made. The system level adjustment may be automated by software or the like thereby making optimization of the optical communications span easier.
H04B 10/08 - Equipment for monitoring, testing or fault measuring
H04J 14/02 - Wavelength-division multiplex systems
H04B 10/077 - Arrangements for monitoring or testing transmission systemsArrangements for fault measurement of transmission systems using an in-service signal using a supervisory or additional signal
H04B 10/079 - Arrangements for monitoring or testing transmission systemsArrangements for fault measurement of transmission systems using an in-service signal using measurements of the data signal
29.
Tilt control through optical pump power adjustment
The adjustment of tilt in an optical signal path of a repeater. The repeater includes an optical pump that optically powers a rare-Earth doped fiber amplifier, which amplifies the optical signal. The optical signal path also includes Raman gain stage implemented in a previous optical fiber span in the optical signal path, and which contributes tilt with respect to wavelength. Adjusting the Raman gain and/or the rare-Earth doped gain also adjusts the combined tilt contributed by these gain stages. However, the rare-Earth doped gain operates at least partially in the saturated regime, thereby stabilizing the gain at the output of the rare-Earth doped amplifier. Thus tilt control may be employed by adjusting optical pump power with reduced effect on overall gain.
H01S 3/30 - Lasers, i.e. devices using stimulated emission of electromagnetic radiation in the infrared, visible or ultraviolet wave range using scattering effects, e.g. stimulated Brillouin or Raman effects
H04B 10/294 - Signal power control in a multiwavelength system, e.g. gain equalisation
H04B 10/291 - Repeaters in which processing or amplification is carried out without conversion of the main signal from optical form
H01S 3/131 - Stabilisation of laser output parameters, e.g. frequency or amplitude by controlling the active medium, e.g. by controlling the processes or apparatus for excitation
H01S 3/23 - Arrangement of two or more lasers not provided for in groups , e.g. tandem arrangement of separate active media
An integrated assembly for switching optical signals. The integrated assembly includes two subassemblies. For instance, the subassemblies might be a shelf assembly and the integrated assembly might be a rack assembly in which the shelf assemblies are connected. Each of the subassemblies includes optical interfaces configured to support communication of optical channels to and from the integrated assembly using the corresponding subassembly. Each subassembly might also include multiple switch fabric assemblies each including a switching mechanism. An inter-subassembly communication interface is provided between each subassembly. An optical signal may be switched from one of the subassemblies (e.g., one of the shelves) to another even though there is no intervening switching circuitry in between the different subassemblies. Instead, the switching operation is distributed between the subassemblies.
H04B 10/00 - Transmission systems employing electromagnetic waves other than radio-waves, e.g. infrared, visible or ultraviolet light, or employing corpuscular radiation, e.g. quantum communication
H04Q 11/00 - Selecting arrangements for multiplex systems
A repeater amplifier assembly that includes at least two chassis containing optics and electronics. The chassis are connected with a size-adjustment mechanism that can adjust a size of the repeater amplifier assembly by reversibly adjusting the positions of the chassis with respect to each other. To insert the repeater amplifier assembly into a repeater housing, the repeater amplifier assembly is accessed in a contracted position. The amplifier is inserted into the housing, and then a control of the size adjustment mechanism is actuated to urge the chassis outwards until the chassis push against the repeater housing. To remove the repeater amplifier assembly from the repeater housing, the control is actuated to cause the size adjustment mechanism to pull the chassis inwards with respect to each other until the chassis no longer push against the repeater housing. The repeater amplifier assembly may then be freely removed from the repeater housing.
The mixing of coherent optical wavelength channels with non-coherent optical wavelength channels. Before mixing, a dispersive element introduces dispersion into the coherent optical wavelength channels and/or into the non-coherent optical wavelength channels such that the dispersion map of the coherent optical wavelength channels is different than the dispersion map of the non-coherent optical wavelength channels. By allowing the coherent channels to have a different dispersion map, the dispersion map may be moved further from the zero dispersion point, which can degrade coherent detection. Accordingly, coherent optical channels and non-coherent optical channels may be transmitted effectively over the same optical link.
An optical assembly in an optical link coupling two optical terminals. The optical assembly receives and demultiplexes two groups of optical wavelength channels which are each treated separately as far as dispersion compensation and discrete amplification are concerned. The optical assembly then multiplexes the two groups back into the same fiber for further transmission. For instance, one group of optical wavelength channels may each be coherent channels, and subject to no dispersion in the optical assembly, while the other group may contain non-coherent channels, which are subject to dispersion compensation in the optical assembly.
Embodiments described herein relate to an optical fiber stretch that may experience forward Raman amplification in which the peak optical signal power occurs at some distance from the transmitter. Smaller effective area optical fiber is used at a portion of the optical fiber stretch in which the optical signal power is increasing, while larger effective area optical fiber is used at a more remote stretch of the optical fiber stretch that experiences the peak optical signal power. Thus, the quality of the signal is better preserved since the larger effective area fiber reduces maximum optical signal density thereby reducing non-linear degradations on signal quality.
G02B 6/28 - Optical coupling means having data bus means, i.e. plural waveguides interconnected and providing an inherently bidirectional system by mixing and splitting signals
H01S 3/00 - Lasers, i.e. devices using stimulated emission of electromagnetic radiation in the infrared, visible or ultraviolet wave range
A system and method are provided for controlling the pre-emphasis applied to an optical signal, in which the output level of individual transmitters is controlled in order to reach a pre-defined desired value of a quality metric. Transmitters are able to adjust their output power without external control in such a way as to optimise the power distribution across the system.
The alteration of the bandwidth of an optical amplifier. Before alteration, optical signals having a first set of wavelengths are provided through a gain medium of the optical amplifier. In addition, a first pump having a set of pump wavelengths is propagated through the gain medium to thereby amplify the optical signals. After alteration, optical signals having at least a partially different set of wavelengths are able to be optically amplified by coupling a second pump into the optical medium. The second pump is at least partially distinct from the first pump in that the second pump includes at least one pump wavelength that was not included in the first pump.
H04B 10/17 - in which processing or amplification is carried out without conversion of the signal from optical form
H01S 3/30 - Lasers, i.e. devices using stimulated emission of electromagnetic radiation in the infrared, visible or ultraviolet wave range using scattering effects, e.g. stimulated Brillouin or Raman effects
H04B 10/12 - Transmission through light guides, e.g. optical fibres (H04B 10/22, H04B 10/24, H04B 10/30 take precedence);;
37.
Optical amplifier with Raman and rare-earth-doped fiber amplifier both pumped efficiently using direct and reflected pump light
An optical amplification mechanism that introduces optical pump(s) into one port of an optical circulator. The optical circulator directs the optical pumps from that port into another port that is coupled to the output of a gain stage. The optical pump(s) then pass from the output to the input of the gain stage while amplifying an optical signal passing from the input to the output of the gain stage. A residual amount of optical pump(s) that exits the input of the gain stage is reflected back into the input of the gain stage. The reflected optical pump(s) then further assists in the amplification of the optical signal. Other embodiments are also disclosed.
H04B 10/17 - in which processing or amplification is carried out without conversion of the signal from optical form
H01S 3/30 - Lasers, i.e. devices using stimulated emission of electromagnetic radiation in the infrared, visible or ultraviolet wave range using scattering effects, e.g. stimulated Brillouin or Raman effects
H04B 10/12 - Transmission through light guides, e.g. optical fibres (H04B 10/22, H04B 10/24, H04B 10/30 take precedence);;
An optical transmission system comprises two optical fibers carrying optical signal traffic between two terminals, and a plurality of optical repeaters coupled to the two fibers each repeater having a permanently connected passive high loss loop back circuit between the two fibers. One terminal includes a transmitter, which launches a pulsed supervisory signal on a dedicated supervisory wavelength into one optical fiber, and a receiver, which detects a portion of the supervisory signal looped back from each repeater in order to identify the existence and location of faults in the transmission system. The pulsed supervisory signal is of sufficiently short duration such that portions of the signal returned from each repeater do not overlap with one another and interference with the counter-propagating traffic is avoided by utilizing a dedicated supervisory wavelength. Each return pulse is integrated sequentially by a single detector and processed by heterodyne reception and synchronous demodulation.
Fiber optic transmission technologies that allow DPSK or even higher order PSK to be performed at 20 gigabits per second per channel or even higher bit rates in a WDM (e.g., DWDM) wavelength multiplexed channeling environment. The technology employs pre-compensation of chromatic error dispersion such for each of most, if not all, channels have a portion of minimum absolute accumulated dispersion that occurs somewhere within the length (perhaps at the mid-point) of the optical channel. Post-compensation is then employed at the receiver to reduce or even potentially eliminate the chromatic dispersion. The technology allows for reduced bit error rates at high bit rates over even very long haul (e.g., trans-oceanic submarine or long terrestrial) optical fiber links, and for all channels.
A method of communicating an optical signal includes generating an optical signal at a bit rate of at least 2.5 Gb/s. The optical signal including at least thirty optical channels. In one particular embodiment, at least some of the thirty optical channels reside within a 1567-1620 nanometer wavelength range. The method also includes receiving the optical signal at a ROPA that includes a rare-earth doped optical fiber. In addition, the method includes introducing a pump signal to a communication span of the unrepeatered optical communication system. The pump signal operable to amplify the optical signal by Raman amplification within the communication span and including at least one pump signal wavelength operable to excite the rare-earth doped fiber. The method further includes receiving the optical signal after the optical signal has traversed at least 200 kilometers of the communication span.
A method of communicating an optical signal includes generating an optical signal at a bit rate of at least 2.5 Gb/s. The optical signal including at least thirty optical channels. In one particular embodiment, at least some of the thirty optical channels reside within a 1567-1620 nanometer wavelength range. The method also includes receiving the optical signal at a ROPA that includes a rare-earth doped optical fiber. In addition, the method includes introducing a pump signal to a communication span of the unrepeatered optical communication system. The pump signal operable to amplify the optical signal by Raman amplification within the communication span and including at least one pump signal wavelength operable to excite the rare-earth doped fiber. The method further includes receiving the optical signal after the optical signal has traversed at least 200 kilometers of the communication span.
G02B 6/28 - Optical coupling means having data bus means, i.e. plural waveguides interconnected and providing an inherently bidirectional system by mixing and splitting signals
An optical communication system includes a plurality of optical add/drop multiplexers (OADMs). The plurality of OADMs includes at least five low distortion OADMs. Each OADM is coupled between spans of a multiple span communication link and operable to receive a multiple wavelength signal. The multiple wavelength signal includes a plurality of bands of wavelength signals each separated from other bands of wavelength signals by one or more guard-channels. In one embodiment, each of the at least five low distortion OADMs adds/drops a common first band of wavelengths to/from the multiple wavelength signal. In some embodiments, a spectral distortion associated with a pass-through wavelength signal spectrally adjacent to one of the one or more guard-channels is no more than three decibels after exiting the last of the plurality of low distortion OADMs. In those embodiments, the guard-channel is adjacent to the first band of wavelengths.
An apparatus for amplifying optical communications systems is provided in which one or more amplifier modules, each containing an optical amplifier and at least two pump lasers, are optically isolated from a plurality of control modules. Each control module controls a single pump laser in one or more of the amplifier modules. A control module can thus be removed without disabling any amplifier module, while the plurality of pump lasers in each amplifier module allow for effective operation even if one of the pump lasers should fail. The pump lasers in each module are controlled by a master-slave relationship, whereby the master pump laser is adjusted to optimise overall output, while the slave laser(s) are adjusted to equalize the power output of the lasers.
An optical communication system includes a gain medium that is capable of receiving at least one optical signal that includes one or more optical signal wavelengths. The system also includes one or more pump sources that are capable of generating at least one pump signal for introduction to the gain medium. The pump signal includes one or more fractional Raman order pump wavelengths having a Raman gain peak that is a non-integer multiple of one stokes shift from each of the one or more optical signal wavelengths. In one particular embodiment, the pump signal interacts with the optical signal as the pump signal traverses at least a portion of the gain medium.
H01S 3/30 - Lasers, i.e. devices using stimulated emission of electromagnetic radiation in the infrared, visible or ultraviolet wave range using scattering effects, e.g. stimulated Brillouin or Raman effects
09 - Scientific and electric apparatus and instruments
38 - Telecommunications services
42 - Scientific, technological and industrial services, research and design
Goods & Services
Computers; computer hardware; computer software; computer networks; network and telecommunications software; telecommunications equipment; optical transmission systems; optical communication systems, networks and equipment; semiconductors; electronic and electromechanical apparatus, all for use with computers and/or computer networks; data recorded in electronic, optical or magnetic form; microprocessors; integrated circuits; electronic assemblies; printed circuit boards; instructional material relating to computers and data, all recorded magnetically, optically or electronically; apparatus and instruments, all for recording, processing, receiving, reproducing, transmitting, modifying, compressing, decompressing, broadcasting, merging or enhancing of data; switching devices for use with local and/or wide area networks; computer network analysers; parts and fittings for all the aforesaid goods; documents, information, text and other media, all being electronically recorded or downloadable from a computer network or the Internet or Extranets; but not including any hardware or software specifically designed for use in relation to financial and/or stock exchange services. Telecommunications services; optical communications services; communications via electronic platforms; electronic data interchange services; telecommunications services for file creation, maintenance and document and information exchange services; communications services via the Intranet, Extranet, Internet and other electronic means; provision of multiple user access to electronic communication networks, including the Internet, Extranets and broad band access; provision of central switching services for electronic communications networks; provision of interface services for electronic communications network services providers; provision of connectivity services and access to electronic communications networks, for transmission or reception of data, audio, video or multimedia content; provision of telecommunications means for accessing and updating information across multiple communications and computing devices; information services relating to the aforesaid including such services provided via the Internet or Extranets; but not including any telecommunications services specifically designed for use in relation to financial and/or stock exchange services. Consultancy, design, testing, research, applications, development and advisory services, all relating to manufacturing, telecommunications, electronic components, computing, networking, computer software, and to optical communications systems; planning, design and implementation of electronic communications systems and networks; providing access to computer databases; enterprise resource planning; encryption, decryption and authentication of information, messages and of data; installation, updating and maintenance of computer software; computer programming; computer systems analysis; creating and maintaining websites; information, consultancy and advisory services relating to the aforesaid, including such services provided on-line from a computer database or via the Internet or Extranets; but not including any database and programming services specifically designed for use in relation to financial and/or stock exchange services.
09 - Scientific and electric apparatus and instruments
Goods & Services
TELECOMMUNICATIONS EQUIPMENT, NAMELY OPTICAL TRANSMISSION SYSTEMS COMPRISED OF CABLES, OPTICAL FIBER, TRANSMITTERS, RECEIVERS, OPTICAL FILTERS, LASERS NOT FOR MEDICAL USE, OPTICAL SIGNAL AMPLIFIERS NOT FOR MEDICAL USE, REGENERATORS WHICH TRANSFORM ELECTRICAL SIGNALS TO OPTICAL SIGNALS OR TRANSFORM OPTICAL SIGNALS TO ELECTRICAL SIGNALS, COMPUTER HARDWARE, AND COMPUTER COMMUNICATIONS SOFTWARE FOR USE IN TRANSMITTING AND RECEIVING OPTICAL COMMUNICATIONS OVER LONG DISTANCES
09 - Scientific and electric apparatus and instruments
Goods & Services
TELECOMMUNICATIONS EQUIPMENT, namely, OPTICAL TRANSMISSION SYSTEMS COMPRISED OF CABLES, OPTICAL FIBER, TRANSMITTERS, RECEIVERS, OPTICAL FILTERS, LASERS NOT FOR MEDICAL USE, OPTICAL SIGNAL AMPLIFIERS NOT FOR MEDICAL USE, REGENERATORS WHICH TRANSFORM ELECTRICAL SIGNALS TO OPTICAL SIGNALS OR TRANSFORM OPTICAL SIGNALS TO ELECTRICAL SIGNALS, COMPUTER HARDWARE, AND COMPUTER COMMUNICATIONS SOFTWARE FOR USE IN TRANSMITTING AND RECEIVING OPTICAL COMMUNICATIONS OVER LONG DISTANCES
