Forward raman pumping with respect to dispersion shifted fiber

Abstract

To provide forward Raman pumping with respect to dispersion shift fibers.SOLUTION: According to an aspect of an embodiment, an optical amplification method may include identifying a first range of signal wavelengths that correspond to a first optical signal configured to propagate via an optical fiber. The method may further include generating a pumping signal having a range of pumping wavelengths, the range of pumping wavelengths being based on a range of dispersion wavelengths, which correspond to the range of pumping wavelengths, not overlapping with the first range of signal wavelengths. The pumping signal may be provided to the optical fiber having the optical signal propagating thereon.SELECTED DRAWING: Figure 2B

Description

Technical Field

[0001] Embodiments discussed in this disclosure relate to Raman amplifiers.

Background Art

[0002] Telecommunication systems, cable television systems, and data communication networks use optical networks to transmit information between remote points. In an optical network, information is transmitted in the form of optical signals through optical fibers or other optical media. An optical network can include various components such as amplifiers, dispersion compensators, multiplexer / demultiplexer filters, wavelength selective switches, couplers, etc., configured to perform various operations within the optical network. Additionally, optical pumping may be used to amplify optical signals propagating through the optical network by interacting the optical signal with a pumping signal.

[0003] The subject matter claimed in this application is not limited to embodiments that solve any disadvantages or that operate only in the environments described above. Rather, this background is provided only to illustrate one exemplary technical field in which some of the embodiments described herein may be implemented.

Summary of the Invention

Means for Solving the Problems

[0004] According to an aspect of an embodiment, an optical amplification method can include identifying a first range of signal wavelengths corresponding to a first optical signal configured to propagate through an optical fiber. The method can further include generating a pumping signal having a range of pumping wavelengths, the range of pumping wavelengths being based on a range of dispersion wavelengths corresponding to the range of pumping wavelengths and not overlapping with the first range of signal wavelengths. The pumping signal may be supplied to the optical fiber through which the optical signal propagates.

[0005] The objectives and advantages of the embodiments are realized and achieved by, at least, the elements, features, and combinations specifically pointed out in the claims. It is understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are not restrictive of the claimed invention.

Brief Description of the Drawings

[0006] Exemplary embodiments are described and explained with further specificity and detail through the use of the accompanying drawings.

[0007]

Figure 1

[0008]

Figure 2A

Figure 2B

Figure 2C

[0009]

Figure 3

[0010]

Figure 4

Modes for Carrying Out the Invention

[0011] An optical network can include nodes configured to communicate information with each other via optical signals carried by optical fibers. In some situations, amplification of an optical signal in an optical fiber can enable the optical signal to travel a longer distance by compensating for losses that can affect the optical signal, such as degradation of the optical signal due to a noisy channel within the optical network.

[0012] Amplification of an optical signal within an optical network may be obtained by optical pumping that can be performed by an optical amplifier. In some situations, an optical amplifier may be suitable for generating linear amplification of a signal by energy transfer of stimulated ions within an optical fiber. Additionally or alternatively, an optical amplifier configured to generate Raman gain (referred to as a "Raman amplifier") may be suitable for generating non - linear amplification of a signal by energy transfer of coupled elements within an optical fiber. In some embodiments, optical amplification may include a pumping signal. For example, a pump source can generate a pumping signal that is sent into an optical fiber. The pumping signal can interact with molecules and / or ions of the optical fiber that can cause scattering of the energy of the pumping signal. The scattered energy is transferred from the pumping signal to the optical signal and can amplify the optical signal. In some embodiments, the pumping signal may be of higher intensity than the optical signal.

[0013] In some embodiments, the Raman amplifier may be configured to perform backward pumping. For example, the pumping signal may be incident on the optical fiber from the output end. The pumping signal can propagate through the optical fiber in a direction opposite to that of the optical signal. In backward pumping, as the pumping signal travels in the opposite direction, the interaction between the pumping signal and the optical signal is reduced. The reduced interaction may mitigate some of the pump-induced noise (e.g., the noise added to the optical signal due to the pumping signal). However, the noise reduction effect using different noise reduction techniques (e.g., fiber type, Raman gain flattening, signal conditioning, optimized pump source, etc.) may not be as effective in backward pumping, which may make it difficult to adjust and / or reduce the noise to meet the system specifications.

[0014] In some embodiments, the Raman amplifier may be configured to perform forward pumping. For example, the pumping signal may be incident on the optical fiber from the input end. The pumping signal can propagate through the optical fiber in the same direction as the optical signal. As the pumping signal travels in the same direction as the optical signal, the interaction between the pumping signal and the optical signal increases, which may cause additional noise to be generated in the optical signal. Some current approaches to forward-pumped Raman amplification may utilize an incoherent pump that can have a wide bandwidth (e.g., 20 - 30 nm). The wide bandwidth can increase the interaction between the pumping signal and the optical signal.

[0015] In some cases, the interaction between the optical signal and the pumping signal can be generated by the dispersion of the signal (e.g., optical signal and / or pumping signal) in the optical fiber. For example, the signal may include a range of wavelengths including different wavelengths when the signal enters a medium such as an optical fiber. When the signal travels through the optical fiber, different wavelengths within the signal can travel at different speeds. Different wavelengths may cause dispersion effects and / or spreading of the signal over different wavelength ranges. In these examples, even when using optical signals and pumping signals generated at different wavelengths, due to dispersion, the optical signal and the pumping signal still interact, which may cause noise in the optical signal and / or add noise to the optical signal.

[0016] In some embodiments, the dispersion effect can occur with respect to the zero-dispersion wavelength of the optical fiber. The zero-dispersion wavelength can refer to a specific wavelength at which the group velocity dispersion of the signal traveling through the optical fiber becomes zero. Since there is no dispersion at the zero-dispersion wavelength, the group velocity dispersion occurs on both sides of the zero-dispersion wavelength. The group velocity dispersion becomes more prominent as the signal moves away from the zero-dispersion wavelength, which may cause an increase in the dispersion effect and the broadening of the pulse. For example, when the signal moves away from the zero-dispersion wavelength towards a shorter wavelength, the optical fiber may cause the shorter wavelength to travel slower than the longer wavelength. In another example, when the signal moves from the zero-dispersion wavelength towards a longer wavelength, the optical fiber may move the longer wavelength slower than the shorter wavelength.

[0017] In some cases, aligning the signal to the zero-dispersion wavelength of the optical fiber may help reduce the pulse dispersion of the optical signal, which may help maintain signal quality and enable a high data rate. However, aligning the signal to the zero-dispersion wavelength may increase the sensitivity to non-linear effects. For example, self-phase modulation and cross-phase modulation are more applied, which may cause signal distortion and degrade signal quality.

[0018] According to one or more embodiments of the present disclosure, the pumping signal of the forward excitation Raman amplifier may be configured to reduce the interaction between the signal corresponding to the pumping signal and the optical signal, thereby reducing noise. For example, the pumping signal may be configured such that the optical signal does not overlap with the pumping signal and / or the dispersion signal corresponding to the pumping signal. For example, the range of the pumping wavelength of the pumping signal may be adjusted according to the range of the input wavelength so that the range of the input wavelength does not overlap with the range of the pumping wavelength and / or the dispersion range of the wavelength corresponding to the pumping signal. Additionally or alternatively, the bandwidth of the pumping signal may be adjusted to be narrower so that the pumping signal and the dispersion signal corresponding to the pumping signal do not overlap with the optical signal.

[0019] Embodiments of the present invention will be described with reference to the drawings.

[0020] FIG. 1 shows an exemplary embodiment of an optical amplification system 100 configured to perform pumping of an optical signal according to at least one embodiment of the present disclosure. The optical amplification system 100 can include an optical fiber 102 and a pump source 106.

[0021] Generally, the optical amplification system 100 may be configured to generate a pumping signal 108 that can amplify the optical signal 104 to generate an amplified optical signal 110. In some embodiments, the optical amplification system 100 may be included in any suitable optical device. For example, the optical amplification system 100 may be included in any suitable Raman amplifier configured to apply Raman amplification to an optical signal.

[0022] The optical signal 104 can include any optical signal configured to carry data. For example, the optical signal 104 can include an optical signal generated by a laser such as a light-emitting diode (LED), a laser diode, and having data modulated thereon, and / or other similar optical signals. In some embodiments, the optical signal 104 can be generated by a source such as an optical transmitter configured to transmit data and / or information through an optical network.

[0023] In some embodiments, the optical signal 104 can include a first wavelength range. For example, the optical signal 104 can include wavelengths within approximately 1525 nm to 1565 nm, which may generally be referred to as the C-band of optical communication. Additionally or alternatively, the optical signal 104 may include a second wavelength range within approximately 1570 nm to 1610 nm, which may generally be referred to as the L-band or optical communication. In these and other embodiments, the first wavelength of the first wavelength range and the second wavelength of the second wavelength range may be amplified by the pumping signal 108 generated by the pump source 106. For example, the interaction between the optical signal 104 and the pumping signal 108 within the optical fiber 102 may generate an amplified optical signal 110.

[0024] In some embodiments, the pump source 106 may include a light source generator configured to generate a pumping signal 108. For example, the pump source 106 may include a laser device configured to generate and / or output a pumping signal such as the pump signal 108. In some embodiments, the pump source 106 may include a broadband laser so that the pumping beam 108 can include a wide range of wavelengths. In some embodiments, the pump source 106 may include a light source generator configured to generate a pumping signal 108. For example, the pump source 106 may include a laser device configured to generate and / or output a pumping beam such as the pump signal 108. In some embodiments, the pump source 106 may include a broadband laser so that the pumping beam 108 can include a wide range of wavelengths. In some embodiments, the pump source 106 may be configured to generate the pump signal 108 as an incoherent pump signal. For example, the pump source 106 may generate an incoherent broadband pumping signal that may be the pumping signal 108 of the optical amplification system 100. In some embodiments, the incoherent pumping signal may include a wide bandwidth (e.g., 20 - 30 nm). In some embodiments, the pump source 106 may include a Fabry - Perot (FP) laser capable of generating a pumping signal 108 having a narrower bandwidth (e.g., 5 nm - 10 nm) compared to the incoherent pumping signal. In other embodiments, the pump source 106 may include a fiber Bragg grating (FBG) laser capable of generating a pumping signal 108 having a narrower bandwidth (e.g., 3 nm or less).

[0025] In some embodiments, the optical fiber 102 may include an optical medium for transmitting optical signals, such as glass or plastic. In some embodiments, the optical fiber 102 may include a dispersion-shifted fiber (DSF). Additionally or alternatively, the optical fiber 102 may include a non-zero DSF. The non-zero DSF may allow non-zero dispersion to be shifted to a specific wavelength to optimize signal transmission characteristics. In some embodiments, the optical fiber 102 may include a zero-dispersion wavelength (ZDW) near 1500 nm.

[0026] In some embodiments, the first wavelength range of the optical signal 104 may not include the ZDW of the optical fiber 102. For example, in the case where the ZDW is at 1500 nm, the first wavelength range may not include 1500 nm. In some embodiments, including the ZDW within the first wavelength range may help reduce the pulse dispersion of the optical signal 104, which may help maintain signal quality and enable a high data rate. However, aligning the optical signal 104 with the ZDW may cause an increase in the sensitivity of the optical signal 104 to non-linear effects. For example, self-phase modulation and cross-phase modulation may be more applied, which may cause signal distortion and degrade signal quality.

[0027] Some traditional implementations of Raman amplifiers may include the use of an incoherent pump that may include a wide bandwidth (e.g., 20 - 30 nm). For example, the pumping signal generated by the incoherent pump can include a range of pumping wavelengths with a width of about 20 - 30 nm. For example, FIG. 2A shows an example of a Raman amplifier with an incoherent pump.

[0028] FIG. 2A shows an exemplary graph 200 representing different optical signals and pumping signals. For example, graph 200 includes a first range of optical signal wavelengths 202 (the "first signal wavelength 202") representing the C band and a second range of optical signal wavelengths 204 (the "second signal wavelength 204") representing the L band. Graph 200 further shows a first range of pumping wavelengths 206 (the "first pumping wavelength 206") representing a wavelength range near 1470 nm. For example, the first pumping wavelength 206 can include a range of 20 - 30 nm with a center point near 1470 nm.

[0029] Additionally or alternatively, the pumping signal may include a second range of pumping wavelengths 208 (the "second pumping wavelength 208"). The second pumping wavelength 208 can represent a wavelength range near 1430 nm. For example, the second pumping wavelength 208 can include a range of 20 - 30 nm with a center point near 1430 nm.

[0030] The pumping signal including the first pumping wavelength 206 and / or the second pumping wavelength 208 may each have a first range of dispersion wavelengths 210 (the "first dispersion wavelength 210") and / or a second range of dispersion wavelengths 212 (the "second dispersion wavelength 212"). The first dispersion wavelength 210 and the second dispersion wavelength 212 can each represent the dispersion of the first pumping wavelength 206 and the second pumping wavelength 208, respectively. In some cases, the dispersion occurs with respect to the ZDW of the optical fiber through which the optical signal and the pumping signal propagate and / or can be illustrated.

[0031] For example, the ZDW of the optical fiber may be 1500 nm. For example, the optical signal and / or pumping signal traveling through the optical fiber may experience different levels of dispersion depending on how close their corresponding wavelengths are to the ZDW of 1500 nm. For example, different wavelengths of the optical signal and the pumping signal may travel at different speeds and / or disperse at different speeds as the wavelength becomes shorter or longer away from the ZDW. For example, the first dispersion wavelength 210 may represent the dispersion of the first pumping wavelength 206 with respect to the ZDW, and the first dispersion wavelength 210 is "reflected" [folded back] across the ZDW compared to the first pumping wavelength 206. Similarly, the second dispersion wavelength 212 may represent the dispersion of the second pumping wavelength 208 with respect to the ZDW, and the second dispersion wavelength 212 is folded back across the ZDW compared to the second pumping wavelength 208.

[0032] As shown in FIG. 2A, the first dispersion wavelength 210 and / or the second dispersion wavelength 212 may overlap with the first signal wavelength 202 and / or the second signal wavelength 204. Such overlap may cause increased noise to the optical signal. Thus, FIG. 2A shows some of the problems that may be caused by traditional techniques using incoherent pumps.

[0033] Returning to FIG. 1, the pumping signal 108 may be adjusted to reduce and / or remove the overlap between the pumping signal 108 and the optical signal 104, as well as the overlap between the dispersion signal associated with the pumping signal 108 and the optical signal 104. For example, the pump source 106 may be configured to adjust the pumping signal 108. The dispersion signal associated with the pumping signal 108 may be adjusted according to the pumping signal 108. In these and other embodiments, the pumping signal 108 may be adjusted using any suitable method. For example, in an example having a pump source 106 as an FP laser, the oscillation wavelength of the FP laser may be adjusted by changing the laser temperature. For example, by adjusting the laser temperature from 25° C. to 65° C., the oscillation wavelength of the FP laser may be adjusted and / or shifted by 20 nm.

[0034] Additionally or alternatively, the bandwidth of the pumping signal 108 may be adjusted to be narrower in order to reduce the overlap. In some embodiments, an optical filter may be used to reduce the bandwidth. In these and other embodiments, any suitable optical filter may be used to reduce and / or adjust the bandwidth. For example, the optical filter may include, among others, a narrowband optical filter, an etalon filter, a fiber Bragg grating, a dichroic filter, a diffraction grating, a tunable filter.

[0035] For example, FIG. 2B shows an exemplary graph 210 representing the adjusted pumping signal. In some embodiments, the graph 210 may include a first optical signal 222 and a second optical signal 224. In some embodiments, the first optical signal 222 may correspond to the C-band of optical communication, and the second optical signal 224 may correspond to the L-band of optical communication. In some embodiments, the first optical signal 222 and / or the second optical signal 224 may be transmitted through an optical fiber. In some embodiments, the optical fiber may include a zero-dispersion wavelength (ZDW) of 1500 nm.

[0036] In some embodiments, one or more pumping signals may be transmitted through an optical fiber together with the first optical signal 222 and / or the second optical signal 224 to amplify the first optical signal 222 and / or the second optical signal 224. For example, the first pumping signal 226, the second pumping signal 228, and / or the third pumping signal 229 may be transmitted through the optical fiber. In these and other embodiments, the pumping signal may have a wavelength such that the pumping signal and the dispersion signal corresponding to the pumping signal do not overlap with the first optical signal 222 and / or the second optical signal 224.

[0037] For example, the first pumping signal 226 may be generated and / or transmitted at a wavelength of 1475 nm. For example, the first pumping signal 226 may include a first range of pumping wavelengths including 1475 nm. In these and other embodiments, the first pumping signal 226 may be dispersed with respect to the ZDW of the optical fiber (e.g., 1500 nm). In some embodiments, the first dispersion signal 230 may correspond to the first pumping signal 226. In these and other embodiments, the first dispersion signal 230 may be on the opposite side of the ZDW compared to the first pumping signal 226, and the first dispersion signal 230 may be "folded back" across the ZDW with respect to the first pumping signal 226. For example, the first pumping signal 226 at 1475 nm may be 25 nm shorter than the ZDW of 1500 nm. The "folding back" may be such that the first dispersion signal 230 includes a first range of dispersion wavelengths including 1525 nm, which may be 25 nm longer than the ZDW of 1500 nm.

[0038] In some embodiments, the first dispersion signal 230 may have a bandwidth corresponding to the bandwidth of the first pumping signal 226. For example, in some embodiments, the first pumping signal 226 may be generated using an FP laser capable of generating a first pumping signal having a bandwidth between about 5 nm and 10 nm. For example, the first range of the pumping wavelength may be in the range of 1470 nm to 1480 nm. Thus, the first range of the dispersion wavelength may be in the range of 1520 nm to 1530 nm. In these and other embodiments, the first dispersion signal 230 may interact with a first optical signal 222 that can be in the range of 1525 nm to 1565 nm (e.g., C-band). In these and other embodiments, the overlap results in an interaction between the first optical signal 222 and the first dispersion signal 230, which can increase the noise of the first optical signal 222.

[0039] In these and other embodiments, the first pumping signal 226 may be adjusted, which may appropriately adjust the first dispersion signal 230 so that the first dispersion signal 230 does not overlap with the first optical signal 222. In some embodiments, the pumping signal 226 may be adjusted and / or shifted to eliminate the overlap between the first dispersion signal 230 and the first optical signal 222. For example, the first pumping signal 226 may be shifted by 20 nm towards the ZDW, which may also shift the first dispersion signal 230 by 20 nm towards the ZDW. By shifting the first dispersion signal 230, the overlap between the first dispersion signal 230 and the first optical signal 222 can be avoided.

[0040] In some embodiments, the shift and / or adjustment may be performed using any method suitable for shifting the wavelength of the signal. For example, an FP laser may be temperature sensitive such that the first pumping signal 226 can be adjusted by changing the laser temperature. For example, by changing the laser temperature from 25°C to 65°C, the first range of the pumping wavelength can be shifted by 20 nm towards the ZDW. For example, the first range of the pumping wavelength may be in the range of 1490 nm to 1500 nm, and the first range of the dispersion wavelength may be in the range of 1500 nm to 1510 nm, avoiding overlap with the first optical signal.

[0041] In some embodiments, such a shift of the first pumping signal 226 may result in the first pumping signal 226 and / or the first dispersion signal 230 overlapping with the ZDW (e.g., 1500 nm). In these and other embodiments, the bandwidth of the first pumping signal 226 may be adjusted to avoid overlap. For example, one or more optical filters may be applied to the first pumping signal 226. For example, optical filters such as, among others, narrowband interference filters, etalon filters, fiber Bragg gratings, distributed feedback lasers, fiber Fabry-Perot filters, etc. can be applied to the pump source to appropriately adjust the bandwidths of the first pumping signal 226 and the first dispersion signal 230. For example, the bandwidths of the first pumping signal 226 and the first dispersion signal 230 may be adjusted to about 5 nm, which may allow the first dispersion signal 230 to avoid overlap with the ZDW similar to the first optical signal 222. For example, the first range of the pumping wavelength may be in the range of 1490 nm to 1495 nm, and the first range of the dispersion bandwidth may be in the range of 1505 nm to 1510 nm.

[0042] In some embodiments, graph 210 may show a second pumping signal 228 and a second dispersion signal 232 associated with the second pumping signal 228. In these and other embodiments, the second dispersion signal 232 may be on the opposite side of the ZDW compared to the second pumping signal 228, and the second dispersion signal 232 may be "reflected" across the ZDW with respect to the second pumping signal 228. For example, the second pumping signal 228 of 1432 nm may be 68 nm shorter than the ZDW of 1500 nm. The "wrap-around" may be such that the second dispersion signal 232 includes a second range of dispersion wavelengths that may be 68 nm longer than the ZDW of 1500 nm, including 1568 nm.

[0043] In some embodiments, the second pumping signal 228 may be adjusted in the same manner as the first pumping signal 226 such that the second dispersion signal 232 does not overlap with the first optical signal 222 and / or the second optical signal 224. If the first optical signal 222 and the second optical signal 224 correspond to the C-band and the L-band, respectively, the second pumping signal 228, which may include a second range of pumping wavelengths, may be adjusted such that the second dispersion signal 232 may enter between the first optical signal 222 and the second optical signal 224 (e.g., between the C-band and the L-band). In these and other embodiments, the second range of dispersion wavelengths corresponding to the second dispersion signal 232 may be adjusted to be within the gap between the first optical signal 222 and the second optical signal 224. In some embodiments, the gap may be relatively narrow (e.g., 5 nm or less). In such a case, the second pumping signal 228 may be shifted and / or narrowed such that the second dispersion signal 232 does not overlap with the first optical signal 222 and / or the second optical signal 224.

[0044] In some embodiments, the pumping signal may be on the same side of the ZDW as the first optical signal 222 and / or the second optical signal 224. For example, the third pumping signal 229 includes a third range of pumping wavelengths including 1510 nm. In these examples, the third dispersion signal 234 corresponding to the third pumping signal 229 may be on the opposite side of the ZDW (e.g., shorter than the ZDW).

[0045] Returning to FIG. 1, in some embodiments, the ZDW may vary based at least on the type of the optical fiber 102. For example, the optical fiber 102 may be a DSF where the ZDW may be about 1550 nm. In these cases, the optical signal 104 may not include a signal on the C band to avoid overlap with the ZDW. In these and other embodiments, an optical communication band may be used for the optical signal 104. For example, the optical signal 104 may include an L band signal.

[0046] For example, FIG. 2C shows an exemplary graph 240 having a first optical signal 242 in the L band. In some embodiments, the L band range may vary from approximately 1565 nm to 1600 nm. For example, the L band range may be narrower (e.g., 1570 nm to 1600 nm) or wider (e.g., 1565 nm to 1605 nm).

[0047] In some embodiments, the pumping signal used to amplify the first optical signal 242 may be appropriately adjusted to avoid overlap with the first optical band 242 and / or the ZDW (e.g., 1550 nm). For example, the first pumping signal 246 and the first dispersion signal 252 corresponding to the first pumping signal 246 may be adjusted to avoid overlap with the first optical signal 242 (e.g., the L band) and / or the ZDW.

[0048] Modifications, additions, or omissions may be made to the optical amplification system 100 without departing from the scope of the present disclosure. For example, in some embodiments, the optical amplification system 100 may include any number of other components that may not be explicitly illustrated or described.

[0049] FIG. 3 is a flowchart of an exemplary method 300 for performing optical pumping configured in accordance with at least one embodiment of the present disclosure. The method 300 may be implemented by any suitable element of an optical pumping system such as the optical amplification system 100 of FIG. 1 described above. Although shown as discrete steps, the various steps of the method 300 may be divided into additional steps, combined into fewer steps, or deleted, depending on the desired implementation. Further, the order of execution of the different steps may vary depending on the desired implementation.

[0050] In some embodiments, the method 300 may begin at block 302. At block 302, a first range of signal wavelengths corresponding to a first optical signal configured to propagate through an optical fiber may be identified. In some embodiments, the first range of signal wavelengths may vary based at least on the type of optical fiber. For example, an optical fiber may be able to amplify certain optical signals within a certain wavelength better than other wavelengths. The first range of signal wavelengths may be selected and / or identified to correspond to the wavelengths that the optical fiber can amplify. For example, different types of optical fibers can amplify different wavelengths. For example, a non-zero dispersion-shifted fiber (NZ-DSF) may be suitable for amplifying signals within the wavelengths of the L-band of the optical transmission band. In these and other embodiments, the first range of signal wavelengths may correspond to the L-band of the optical transmission band. The optical fiber may include any suitable type of optical fiber that may be used to amplify an optical signal. In some embodiments, the first range of signal wavelengths may be selected according to different types of optical fibers.

[0051] In some embodiments, the second range of signal wavelengths corresponding to the second optical signal can be selected and / or identified to correspond to wavelengths that the optical fiber can amplify. For example, in some cases, the optical fiber can include a standard single mode fiber (SMF) that can be suitable for amplifying signals within wavelengths corresponding to the L-band and C-band of the optical transmission band. In some embodiments, the second range of signal wavelengths may be different from the first range of signal wavelengths. For example, in some embodiments, the wavelengths in the second range may correspond to the C-band.

[0052] In block 304, a pumping signal having a range of pumping wavelengths may be generated. In some embodiments, the range of pumping wavelengths may be determined based at least on a range of dispersion wavelengths corresponding to a range of pumping wavelengths that does not overlap with the first range of signal wavelengths as described in this disclosure with respect to FIGS. 1 and 2A - 2C.

[0053] In some embodiments, the range of dispersion wavelengths can correspond to the relationship between the range of pumping wavelengths and the zero - dispersion wavelength (ZDW) corresponding to the optical fiber. For example, the ZDW of the optical fiber may be such that a signal traveling through the optical fiber experiences minimal dispersion. For example, a signal can include a range of wavelengths including different wavelengths when the signal enters a medium such as an optical fiber. When the signal travels through the optical fiber, different wavelengths within the signal may travel at different speeds, causing group - velocity dispersion. For example, the signal can experience positive group - velocity dispersion where shorter wavelengths travel faster than longer wavelengths and / or negative group - velocity dispersion where longer wavelengths travel faster than shorter wavelengths. The ZDW can represent a specific wavelength at which the group - velocity dispersion can be substantially zero.

[0054] In some embodiments, dispersion of the signal can occur with respect to the ZDW. For example, the range of the dispersion wavelengths may be "reflected" across the ZDW as compared to the range of the pumping wavelengths. In these and other embodiments, the range of the pumping wavelengths may be generated such that the range of the pumping wavelengths and / or the range of the dispersion wavelengths do not overlap with the signal wavelengths of the first range and / or the signal wavelengths of the second range as described in this disclosure with respect to FIGS. 1 and 2A - 2C.

[0055] In some embodiments, the pumping source that generates the pumping signal may be configured to generate the pumping signal in a certain wavelength range. In some embodiments, the certain wavelength range may be inappropriate in that the range of the pumping wavelengths and / or the range of the dispersion wavelengths overlap with the first range of the signal wavelengths and / or the second range of the signal wavelengths. In these and other embodiments, the range of the pumping wavelengths may be adjusted by adjusting the pumping source. For example, the adjustment may be made to move the range of the pumping wavelengths such that the corresponding range of the dispersion wavelengths does not overlap with the first range of the signal wavelengths and / or the second range of the signal wavelengths. In some embodiments, the range of the pumping wavelengths may be modified by modifying the temperature of the pumping source and / or the laser used to generate the pumping signal. In some embodiments, any other suitable method may be used to adjust the pumping signal. Additionally or alternatively, the bandwidth of the pumping signal may be adjusted (e.g., to be narrower). For example, one or more optical filters can be used to adjust the bandwidth.

[0056] In block 306, the pumping signal may be provided to the optical fiber through which the optical signal propagates. For example, the pumping signal may be used to amplify the first optical signal and / or the second optical signal. For example, the pumping signal may interact with the molecules and / or ions of the optical fiber that can cause scattering of the energy of the pumping signal. The scattered energy is transferred from the pumping signal to the optical signal, and the optical signal can be amplified.

[0057] Modifications, additions, or omissions may be made to method 300 without departing from the scope of the present disclosure. For example, the steps and operations outlined are provided by way of example only, and some of the steps and operations may be optional, may be combined into fewer steps and operations, or may be expanded into additional steps and operations without detracting from the essence of the disclosed embodiments.

[0058] FIG. 4 shows a block diagram of an exemplary computing system 402 according to at least one embodiment of the present disclosure. The computing system 402 may be configured to implement or direct one or more suitable operations described in the present disclosure. For example, the computing system 402 may be configured to direct the pumping source 106 to adjust the wavelength of the pumping signal 108 as described and illustrated in FIG. 1. The computing system 402 may include a processor 450, a memory 452, and a data storage 454. The processor 450, the memory 452, and the data storage 454 may be communicatively coupled.

[0059] Generally, processor 450 can include any suitable dedicated or general-purpose computer, computing entity, or processing device that includes various computer hardware or software modules, and can be configured to execute instructions stored on any applicable computer-readable storage medium. For example, processor 450 can include a microprocessor, a microcontroller, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or any other digital or analog circuit configured to interpret and / or execute program instructions and / or process data. Although shown as a single processor in FIG. 4, processor 450 can include any number of processors configured to individually or collectively execute or direct the execution of any number of operations described in this disclosure. Additionally, one or more of the processors may be present on one or more different electronic devices such as different servers.

[0060] In some embodiments, processor 450 can be configured to interpret and / or execute program instructions stored in memory 452, data storage 454, or both memory 452 and data storage 454, and / or process data. In some embodiments, processor 450 can fetch program instructions from data storage 454 and load the program instructions into memory 452. After the program instructions are loaded into memory 452, processor 450 may execute the program instructions.

[0061] Memory 452 and data storage 454 may include a computer-readable storage medium that carries or stores computer-executable instructions or data structures. By way of example and not limitation, such computer-readable storage media can include random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), compact disc read-only memory (CD-ROM) or other optical disk storage, magnetic disk storage or other magnetic storage devices, flash memory devices (e.g., solid state memory devices), or any other non-transitory storage medium that can be used to carry or store particular program code in the form of computer-executable instructions or data structures and that can be accessed by a general purpose or special purpose computer. In these and other embodiments, the term "non-transitory" as used in this disclosure should be construed to exclude only those types of transitory media that are considered outside the scope of patentable subject matter in the Federal Circuit decision of In re Nuijten, 500 F.3d 1346 (Fed. Cir. 2007).

[0062] The above combinations can also be included within the scope of the computer-readable storage medium. The computer-executable instructions may include, for example, instructions and data configured to cause a processor 450 to perform a particular operation or group of operations.

[0063] Modifications, additions, or omissions may be made to computing system 402 without departing from the scope of the present disclosure. For example, in some embodiments, computing system 402 may include any number of other components that may not be explicitly illustrated or described.

[0064] The terms used in this disclosure, particularly in the appended claims (e.g., the body of the appended claims), are generally intended to be "open" terms (e.g., the term "comprising" should be construed as "comprising, but not limited to", the term "having" should be construed as "having at least...", the term "including" should be construed as "including, but not limited to", etc.).

[0065] Furthermore, if a specific number of claim recitations is intended, such intent is explicitly recited in the claim, and if there is no such recitation, such intent does not exist. For example, for purposes of illustration, the following appended claims may include the use of introductory phrases "at least one" and "one or more" to introduce claim recitations. However, the use of such phrases should not be construed as implying that the introduction of a claim recitation by the indefinite article "a" or "an" limits any particular claim that includes such introduced claim recitation to embodiments that include only one such recitation, even if the same claim includes both an introductory phrase such as "one or more" or "at least one", and an indefinite article such as "a" or "an" (e.g., "a" and / or "an" should be construed to mean "at least one" or "one or more"); the same holds true for the use of definite articles used to introduce claim recitations.

[0066] In addition, even if a specific number of introduced claim recitations is explicitly recited, one of ordinary skill in the art will recognize that such recitation should be construed as meaning at least the recited number (e.g., a recitation of simply "two recitations" without other modifiers means at least two recitations, or two or more recitations). Further, when conventional expressions similar to "at least one of A, B, and C" or "one or more of A, B, and C" are used, generally such constructions are intended to include only A, only B, only C, A and B, A and C, B and C, or A, B, and C, etc.

[0067] Furthermore, any discrete word or phrase that presents two or more alternative terms should be understood as contemplating the inclusion of one of those terms, any of those terms, or both terms in the present document, claims, or drawings. For example, the phrase "A or B" should be understood as including the possibilities of "A" or "B" or "A and B". This is the case even when the term "and / or" is used elsewhere.

[0068] All examples and conditional language recited in this disclosure are intended for educational purposes to help the reader understand the concepts contributed by the disclosure and the inventors to advance the art, and are to be construed without limitation to such specifically recited examples and conditions. Although embodiments of the disclosure have been described in detail, various changes, substitutions, and alterations can be made without departing from the spirit and scope of the disclosure.

[0069] Regarding embodiments including the above examples, the following additional appendices are disclosed. (Appendix 1) Identifying a first range of signal wavelengths corresponding to a first optical signal configured to propagate through an optical fiber; Generating a pumping signal having a range of pumping wavelengths, wherein the range of the pumping wavelengths is based on a range of dispersion wavelengths corresponding to the range of the pumping wavelengths, the dispersion wavelengths do not overlap with the first range of the signal wavelengths; and providing the pumping signal to the optical fiber through which the first optical signal propagates. Method. (Appendix 2) The method according to Appendix 1, wherein the range of the pumping wavelengths is further based on the range of the dispersion wavelengths not overlapping with a second range of signal wavelengths corresponding to a second optical signal configured to propagate through the optical fiber. (Appendix 3) The first range of the signal wavelength corresponds to the L band of the optical transmission band; The second range of the signal wavelength corresponds to the C band of the optical transmission band. The method according to Appendix 2. (Appendix 4) The method according to Appendix 1, wherein the range of the dispersion wavelength corresponds to the relationship between the range of the pumping wavelength and the zero-dispersion wavelength corresponding to the optical fiber. (Appendix 5) The method according to Appendix 1, wherein, in order to obtain the range of the pumping wavelength, the range before the pumping wavelength is corrected based on the fact that the range before the dispersion wavelength corresponding to the range before the pumping wavelength overlaps with the first range of the signal wavelength. (Appendix 6) The method according to Appendix 5, wherein the range before the pumping wavelength is corrected by correcting the temperature of the laser used to generate the pumping signal, and the range of the pumping wavelength is obtained. (Appendix 7) The range of the pumping wavelength is on the first side of the zero-dispersion wavelength corresponding to the optical fiber; The first range of the signal wavelength is on the second side of the zero-dispersion wavelength. The method according to Appendix 1. (Appendix 8) The method according to Appendix 1, wherein the first range of the signal wavelength corresponds to the L band of the optical transmission band. (Appendix 9) The method according to Appendix 1, wherein the first range of the signal wavelength corresponds to the C band of the optical transmission band. (Appendix 10) The method according to Appendix 1, wherein the range of the dispersion wavelength corresponds to the group velocity dispersion of the range of the pumping wavelength. (Appendix 11) A pumping laser configured to generate a pumping signal having a range of pumping wavelengths, wherein the range of the pumping wavelength is based on the range of the dispersion wavelength corresponding to the range of the pumping wavelength, The dispersion wavelength does not overlap with a first range of signal wavelengths corresponding to a first optical signal configured to propagate through an optical fiber. a pumping laser; and an optical coupler configured to propagate the pumping signal through the optical fiber. An optical pumping system. (Appendix 12) The range of the pumping wavelength is further based on the fact that the range of the dispersion wavelength does not overlap with a second range of signal wavelengths corresponding to a second optical signal configured to propagate through the optical fiber, the optical pumping system according to Appendix 11. (Appendix 13) The first range of the signal wavelength corresponds to the L band of the optical transmission band; The second range of the signal wavelength corresponds to the C band of the optical transmission band, The optical pumping system according to Appendix 12. (Appendix 14) The range of the dispersion wavelength corresponds to the relationship between the range of the pumping wavelength and the zero-dispersion wavelength corresponding to the optical fiber, the optical pumping system according to Appendix 11. (Appendix 15) To obtain the range of the pumping wavelength, the previous range of the pumping wavelength is corrected based on the fact that the previous range of the dispersion wavelength corresponding to the previous range of the pumping wavelength overlaps with the first range of the signal wavelength, the optical pumping system according to Appendix 11. (Appendix 16) By correcting the temperature of the laser used to generate the pumping signal, the previous range of the pumping wavelength is corrected to obtain the range of the pumping wavelength, the optical pumping system according to Appendix 15. (Appendix 17) The range of the pumping wavelength is on a first side of the zero-dispersion wavelength corresponding to the optical fiber; The first range of the signal wavelength is on a second side of the zero-dispersion wavelength, The optical pumping system according to Appendix 11. (Appendix 18) The first range of the signal wavelength corresponds to the L band of the optical transmission band, and is the optical pumping system described in Appendix 11. (Appendix 19) The first range of the signal wavelength corresponds to the C band of the optical transmission band, and is the optical pumping system described in Appendix 11. (Appendix 20) The range of the dispersion wavelength is generated from the group velocity dispersion of the range of the pumping wavelength, and is the optical pumping system described in Appendix 11.

Explanation of symbols

[0070] 102 Optical fiber 104 Input optical signal 106 Pump source 108 Pumping signal 110 Amplified optical signal 202, 222, 242 C band 204, 224 L band Identify the first range of signal wavelengths corresponding to the first optical signal configured to propagate through the optical fiber 302 Generate a pumping signal having a certain range of pumping wavelengths. The range of the pumping wavelengths is based on the range of the dispersion wavelengths corresponding to the range of the pumping wavelengths that does not overlap with the first range of the signal wavelengths Provide the pumping signal to the optical fiber through which the optical signal propagates

Claims

1. identifying a first range of signal wavelengths corresponding to a first optical signal configured to propagate through the optical fiber; generating a pump signal having a range of pump wavelengths; the range of pump wavelengths is based on a range of dispersion wavelengths corresponding to the range of pump wavelengths; the dispersion wavelength does not overlap with the first range of signal wavelengths; providing the pump signal to the optical fiber through which the first optical signal propagates. method.

2. 2. The method of claim 1, further based on the range of pump wavelengths being non-overlapping with a second range of signal wavelengths corresponding to a second optical signal configured to propagate through the optical fiber.

3. the first range of signal wavelengths corresponds to an L-band of an optical transmission band; the second range of signal wavelengths corresponds to the C-band of the optical transmission band; The method of claim 2.

4. The method of claim 1 , wherein the range of dispersion wavelengths corresponds to a relationship between the range of pump wavelengths and a zero dispersion wavelength corresponding to the optical fiber.

5. 2. The method of claim 1, wherein to obtain the range of pump wavelengths, a previous range of pump wavelengths is modified based on a previous range of dispersion wavelengths corresponding to the previous range of pump wavelengths overlapping with the first range of signal wavelengths.

6. The method of claim 5 , wherein the previous range of pump wavelengths is modified to obtain the range of pump wavelengths by modifying a temperature of a laser used to generate the pump signal.

7. the range of pumping wavelengths is on a first side of a zero dispersion wavelength corresponding to the optical fiber; the first range of signal wavelengths is on a second side of the zero dispersion wavelength; The method of claim 1.

8. The method of claim 1 , wherein the first range of signal wavelengths corresponds to an L-band of an optical transmission band.

9. The method of claim 1 , wherein the first range of signal wavelengths corresponds to a C-band of an optical transmission band.

10. The method of claim 1 , wherein the range of dispersion wavelengths corresponds to group velocity dispersion of the range of pump wavelengths.

11. a pump laser configured to generate a pump signal having a range of pump wavelengths, the range of pump wavelengths is based on a range of dispersion wavelengths corresponding to the range of pump wavelengths; the dispersion wavelength does not overlap a first range of signal wavelengths corresponding to a first optical signal configured to propagate through the optical fiber; a pumping laser; an optical coupler configured to propagate the pump signal through the optical fiber; Optical pumping system.

12. 12. The optical pumping system of claim 11, further based on the range of pump wavelengths being non-overlapping with a second range of signal wavelengths corresponding to a second optical signal configured to propagate through the optical fiber.

13. the first range of signal wavelengths corresponds to an L-band of an optical transmission band; the second range of signal wavelengths corresponds to the C-band of the optical transmission band; 13. An optical pumping system according to claim 12.

14. 12. The optical pumping system of claim 11, wherein said range of dispersion wavelengths corresponds to a relationship between said range of pump wavelengths and a zero dispersion wavelength corresponding to said optical fiber.

15. 12. The optical pumping system of claim 11, wherein to obtain the range of pump wavelengths, a previous range of pump wavelengths is modified based on a previous range of dispersion wavelengths corresponding to the previous range of pump wavelengths overlapping with the first range of signal wavelengths.

16. 16. The optical pumping system of claim 15, wherein the previous range of pump wavelengths is modified to obtain the range of pump wavelengths by modifying a temperature of a laser used to generate the pump signal.

17. the range of pumping wavelengths is on a first side of a zero dispersion wavelength corresponding to the optical fiber; the first range of signal wavelengths is on a second side of the zero dispersion wavelength; 12. An optical pumping system according to claim 11.

18. 12. The optical pumping system of claim 11, wherein said first range of signal wavelengths corresponds to the L-band of the optical transmission band.

19. 12. The optical pumping system of claim 11, wherein the first range of signal wavelengths corresponds to the C-band of an optical transmission band.

20. 12. The optical pumping system of claim 11, wherein said range of dispersion wavelengths is generated from group velocity dispersion of said range of pump wavelengths.

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