Remote pump power amplifier module and non-relay optical fiber transmission system
By using Raman noise suppression technology in optical fibers, the problem of pump optical power drop caused by the nonlinear effect of optical fibers is solved, and higher pump optical power injection and longer transmission distance without relay fibers are achieved.
Patent Information
- Application Number
- CN202410344655.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-03-25
- Publication Date
- 2024-12-20
AI Technical Summary
The nonlinear effect of optical fibers limits the ability to extend the transmission distance without relay by increasing the pump source output power, resulting in the 1480nm wavelength pump optical power not increasing but instead dropping, and being unstable.
Raman noise suppression technology is adopted, by plugging multiple Raman pump noise suppressors into the optical fiber, self-excited Raman scattering and stimulated Raman amplification are suppressed, laser effect is removed, and the pump optical power injected into the optical fiber is increased.
It effectively increases the pump optical power, improves the gain of the far pump module, extends the transmission distance of the relay-free optical fiber communication system, and maintains the stability of the pump optical.
Smart Images
Figure CN119172001A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the field of communication technology, and in particular to a remote pump power amplifier module and a non-relay optical fiber transmission system. Background Art
[0002] With the development of communication technology, the length of communication optical cables has also increased significantly. Ultra-long-distance non-relay optical transmission technology can solve the problems of difficult line management and low management quality and efficiency caused by the increase in line length, and there is no need to add relay equipment, thus reducing transmission costs.
[0003] Due to the limitation of optical cable dispersion and loss, the non-relay optical transmission distance of various ultra-long-distance optical fiber communication systems is generally within 350km. In order to extend the non-relay transmission distance, various ultra-long-distance transmission schemes use high-power erbium-doped fiber amplifiers, unidirectional / bidirectional Raman amplifiers, remote pump amplification technology, forward error correction (FEC) coding technology, etc. At present, most of the remote pump amplification systems used in domestic ultra-long-distance optical fiber communications are first-order remote pumps, which directly transmit 14xx nm pump light to the remote gain unit (RGU) to amplify the signal.
[0004] The main factors limiting ultra-long-distance transmission are loss, dispersion, and optical signal-to-noise ratio (OSNR). In actual transmission systems, loss limitation can be overcome by erbium-doped fiber amplifiers and Raman fiber amplifiers, and dispersion limitation can be overcome by dispersion compensation technology. The ultimate limiting factor of the system is OSNR. The use of remote pump amplifier technology can further improve the sensitivity of the system. At present, remote pump amplification technology has been widely used in the field of unrelayed submarine optical cable transmission and optical fiber communication of power systems. Lasers with output power of several watts in the pump wavelength range of 1450nm to 1490nm have begun to be used in the market. The use of remote pump amplifiers can increase the system transmission power, extend the transmission distance, and reduce costs.
[0005] Remote pumping amplifiers, also known as remote pump amplifiers, are mainly used in ultra-long-distance non-relay optical transmission systems to increase system power budget and extend transmission distance. The so-called remote pumping is to introduce a remote gain module into the transmission system, place the erbium-doped fiber and related passive components in the junction box, and connect them at a specific position of the transmission fiber. There are no active components, no power supply facilities, and no maintenance required. A pump source is placed at the receiving end of the system to provide a high-power pump source to the remote gain module to increase the signal gain.
[0006] Due to the nonlinearity of optical fiber, there are certain requirements for the 1480nm pump light power, which limits the ability to increase the span of a long-span non-relay optical transmission system by increasing the output power of the pump source. The nonlinearity of optical fiber consumes the energy of the 1480nm wavelength pump light. Even if the pump source power is increased, the 1480nm wavelength optical power reaching the long-distance optical fiber L1 will not increase but decrease, and at the same time, the 1480nm wavelength pump light power becomes very unstable.
[0007] Due to the nonlinear effect of optical fiber (the nonlinearity of optical fiber means that when the optical fiber transmits optical signals, its characteristics are no longer in a simple linear relationship with the optical power. Under normal weak light conditions, the optical fiber can be regarded as a linear medium, which means that the change in input optical power is proportional to the change in output optical power. However, when the optical power increases to a certain level, the physical properties of the optical fiber material begin to change, resulting in a nonlinear effect on the propagation of light), there are certain requirements for the 1480nm pump light power, which limits the ability to increase the span of a large-span non-relay optical transmission system by increasing the output power of the pump source. The nonlinearity of optical fiber consumes the energy of the 1480nm wavelength pump light. Even if the pump source power is increased, the 1480nm wavelength optical power reaching the long-distance optical fiber L1 will not increase but decrease, and the 1480nm wavelength pump light power will become very unstable.
[0008] The information disclosed in this background technology section is only intended to deepen the understanding of the overall background technology of the present invention, and should not be regarded as acknowledging or suggesting in any form that the information constitutes the prior art already known to those skilled in the art. Summary of the invention
[0009] In view of the problems existing in the prior art, the present invention provides a remote pump power amplifier module and a repeater-free optical fiber transmission system.
[0010] The technical solution of the present invention provides a remote pump power amplifier module, comprising:
[0011] A remote pump power amplifier pump source, wherein the pump power of the remote pump power amplifier pump source is greater than 32.8dBm;
[0012] A transmission optical fiber segment, one end of which is connected to the remote pump power amplifier pump source;
[0013] a first noise suppressor connected to the other end of the transmission optical fiber segment;
[0014] A combiner, wherein an input end of the combiner comprises at least two channels, one of which is connected to the first noise suppressor, and the other is used to connect to a signal optical fiber; and
[0015] An erbium-doped fiber amplifier is connected to the output end of the combiner.
[0016] Optionally, the transmission optical fiber segment includes:
[0017] A plurality of sections of sub-optical fiber, wherein a second noise suppressor is connected between every two adjacent sub-optical fibers in the plurality of sections of sub-optical fiber.
[0018] Optionally, the sum of the lengths of the multiple sections of sub-optical fibers is equal to the length of the signal optical fiber.
[0019] Optionally, the number of the second noise suppressors is 2 or 3.
[0020] Optionally, the pump power of the remote pump power amplifier pump source is 36.6dBm-37.5dBm.
[0021] Optionally, the maximum carrying power of the second noise suppressor closest to the remote pump amplifier pump source is greater than the maximum carrying power of other second noise suppressors.
[0022] Optionally, the distances between each of the sub-optical fibers are equal.
[0023] Optionally, the first noise suppressor is used to remove the laser effect caused by the combination of stimulated Raman scattering and double Rayleigh scattering in the transmission optical fiber segment.
[0024] The technical solution of the present invention also provides a non-relay optical fiber transmission system, comprising the remote pump power amplifier module.
[0025] Optionally, the remote pump power amplifier module is forward pumped or backward pumped.
[0026] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS
[0027] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.
[0028] Figure 1 is a block diagram of an ultra-long-distance non-relay optical fiber transmission system;
[0029] Figure 2 A structural refinement diagram of a remote pump power amplifier module in the ultra-long-distance non-relay optical fiber transmission system;
[0030] Figure 3 It is a light path diagram for testing the nonlinear effect of optical fiber;
[0031] Figure 4 A spectrum diagram of the experiment of the test optical fiber;
[0032] Figure 5 A schematic diagram of the structure of a device for solving the nonlinear effect of optical fiber according to an embodiment of the present invention;
[0033] Figure 6 For Press Figure 5 Spectrum measured by the noise suppression solution;
[0034] Figure 7 A schematic diagram of the structure of a remote pump power amplifier module provided by the technical solution of one embodiment of the present invention;
[0035] Figure 8 The figure is a schematic structural diagram of a forward-pumped ultra-long-distance non-relay optical fiber transmission system. DETAILED DESCRIPTION
[0036] The advantages of the present invention are further described below in conjunction with the accompanying drawings and specific embodiments.
[0037] Exemplary embodiments will be described in detail herein, examples of which are shown in the accompanying drawings. When the following description refers to the drawings, the same numbers in different drawings represent the same or similar elements unless otherwise indicated. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present disclosure. Instead, they are merely examples of devices and methods consistent with some aspects of the present disclosure as detailed in the appended claims.
[0038] The terms used in this disclosure are for the purpose of describing specific embodiments only and are not intended to limit the disclosure. The singular forms of "a", "said" and "the" used in this disclosure and the appended claims are also intended to include plural forms unless the context clearly indicates otherwise. It should also be understood that the term "and / or" used herein refers to and includes any or all possible combinations of one or more associated listed items.
[0039] It should be understood that although the terms first, second, third, etc. may be used in the present disclosure to describe various information, such information should not be limited to these terms. These terms are only used to distinguish the same type of information from each other. For example, without departing from the scope of the present disclosure, the first information may also be referred to as the second information, and similarly, the second information may also be referred to as the first information. Depending on the context, the word "if" as used herein may be interpreted as "at the time of" or "when" or "in response to determining".
[0040] In the description of the present invention, it is necessary to understand that the terms "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.
[0041] In the description of the present invention, unless otherwise specified and limited, it should be noted that the terms "installed", "connected" and "connected" should be understood in a broad sense. For example, it can be a mechanical connection or an electrical connection, or it can be the internal connection between two components. It can be a direct connection or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to the specific circumstances.
[0042] In the following description, the suffixes such as "module", "component" or "unit" used to represent elements are only used to facilitate the description of the present invention, and have no specific meanings. Therefore, "module" and "component" can be used interchangeably.
[0043] Figure 1 A block diagram of an ultra-long-distance non-relay optical fiber transmission system is shown in FIG. Figure 1 As shown, at the transmitting end, the optical signal amplified by the power amplifier enters the remote pump amplifier module after being transmitted through the long-distance optical fiber L1. The pump source of the remote pump amplifier module is at the transmitting end. After the same transmission distance L1 as the signal light, the remaining pump light is injected into the remote pump amplifier to amplify the signal light.
[0044] Among them, SDH (Synchronous Digital Hierarchy) is a synchronous digital system, an international standard optical fiber transmission system, used to transmit multi-channel digital signals in optical communication networks. It provides a standardized method to encapsulate, multiplex and transmit electrical signals of different rates, and includes a series of management and maintenance functions to ensure the reliability and efficiency of the network.
[0045] FEC (Forward Error Correction) is the abbreviation of forward error correction, which is an error control coding technology. In optical communication, FEC encodes data at the sending end and adds some redundant information, so that the receiving end can detect and correct the bit errors introduced during the transmission process to a certain extent, thereby improving the signal-to-noise ratio and transmission distance of the communication system.
[0046] BA (Booster Amplifier) is the abbreviation of booster. In optical communication systems, it is a device used to boost the power of optical signals. It is usually used to compensate for signal attenuation in long-distance transmission to ensure that the signal has enough energy when it reaches the receiving end.
[0047] PA (Power Amplifier) is the abbreviation of power amplifier.
[0048] Figure 2 is a structural refinement diagram of a remote pump power amplifier module in the ultra-long-distance non-relay optical fiber transmission system, such as Figure 2 As shown, WDM (WDM is the abbreviation of Wavelength-Division Multiplexing, which is a technology for simultaneously transmitting multiple optical signals of different wavelengths in optical fiber communication. In a WDM system, each independent data channel is modulated to a specific wavelength generated by a different laser. These optical signals of different wavelengths are combined together through a combiner and then transmitted simultaneously in the same optical fiber. At the receiving end, the optical signals of each wavelength are separated by a demultiplexer, and then demodulated and the data is recovered by the corresponding receiver.) The remaining pump light and the attenuated signal light are combined and injected into the gain medium EDF (Erbium-Doped Fiber) to amplify the signal light, and then continue to transmit forward through the isolator. The greater the power of the remaining pump light, the greater the gain of the far pump module and the stronger the signal. Therefore, increasing the pump light power injected into the far pump module plays a key role in extending the distance of the relay-free system.
[0049] Due to the nonlinearity of optical fiber, there are certain requirements for the 1480nm pump light power, which limits the ability to increase the span of a long-span non-relay optical transmission system by increasing the output power of the pump source. The nonlinearity of optical fiber consumes the energy of the 1480nm wavelength pump light. Even if the pump source power is increased, the 1480nm wavelength optical power reaching the long-distance optical fiber L1 will not increase but decrease, and at the same time, the 1480nm wavelength pump light power becomes very unstable.
[0050] The inventor conducted an experiment to test the optical fiber. Figure 3 is a light path diagram for testing the nonlinear effect of optical fiber, such as Figure 3 As shown in the figure, G.652D fiber is used for testing in the experiment. The Raman effect of G.652D fiber is smaller than that of G.652 fiber, so the pump power injected into the fiber can be increased. The pump source optical power is injected into the G.652D fiber at 31.0dBm, 32.0dBm, 32.6dBm and 32.8dBm respectively. The spectrum of G.652D fiber is observed by spectrum analyzer at the distance from pump source L.
[0051] Figure 4 The spectrum diagram of the test fiber experiment is as follows: Figure 4 As shown in the figure, when the pump source optical power is 31dBm, no Raman effect occurs after the pump light is transmitted to L in the G.654 optical fiber. When the pump source optical power increases to 32.0dBm, the Raman effect begins to appear after it is transmitted to L. When the pump source optical power continues to increase to 32.6dBm, the Raman effect becomes more and more obvious. When the pump power reaches 32.8dBm, the peak amplitude of the optical power appearing around 1585nm is only 20dB smaller than the peak optical power of 1480nm wavelength. That is to say, continuing to increase the power of the 1480nm pump light will cause the 1480nm wavelength light at L to disappear completely instead of increasing. This is completely contrary to the desire to increase the output power of the 1480nm wavelength light at L by increasing the output power of the pump source, thereby increasing the transmission station distance of the relay-free optical transmission system.
[0052] In order to solve this problem, the present invention provides an embodiment for solving the nonlinear effect of optical fiber. Figure 5 FIG. 1 is a schematic diagram of a device structure for solving the nonlinear effect of optical fiber according to an embodiment of the present invention. Figure 5 As shown, this embodiment uses Raman noise suppression technology to reduce the nonlinear effect of the optical fiber, thereby increasing the pump light power injected into the optical fiber, and solves the transmission problem of high-power pump light by plugging three Raman pump noise suppressors on the G.652D optical fiber, where L1+L2+L3=L. This set of cascaded Raman pump noise suppressors provides a great loss for the wavelength with the largest Raman gain, effectively suppresses self-excited Raman scattering and stimulated Raman amplification, avoids the laser oscillation phenomenon caused by the nonlinearity of the optical fiber, and effectively solves the long-distance transmission of high-power pump light.
[0053] Furthermore, the noise suppressor 1 after the L1 fiber uses high power because the output power of the pump source is high. The noise suppressor 3 after the L3 fiber is used to remove the laser effect caused by the combination of stimulated Raman scattering and double Rayleigh scattering, thereby effectively increasing the pump power injected into the fiber.
[0054] Figure 6 For Press Figure 5 The spectrum measured by the noise suppression solution is as follows: Figure 6As shown in the figure, the spectrum diagram shows the spectrum diagram of the pump light after passing through the long-distance G.652D optical fiber when the optical power of the 1480nm wavelength pump source is adjusted to 34.5dBm, 35.4dBm and 36.6dBm respectively. It can be seen that the use of Raman noise suppression technology greatly increases the pump source optical power that can be injected into the transmission optical fiber. After using Raman noise suppression technology, even if the pump source power is as high as 36.6dBm, the peak power it generates in the 1585nm band is much less than the peak power of the 1480nm band (about 20dB), and when the pump source power is less than 34.5dBm, no power transfer from 1480nm to 1585nm is found. This is the same as the transmission characteristics of the pump light with a pump source power of 31dBm when Raman noise suppression technology is not used.
[0055] In one embodiment, when the power of the remote pump amplifier pump source reaches 37.5 dBm, it is still effective, further extending the transmission distance.
[0056] Figure 7 A schematic diagram of a remote pump power amplifier module is provided as a technical solution of an embodiment of the present invention. Figure 7 As shown, the technical solution of the present invention provides a remote pump power amplifier module, comprising:
[0057] A remote pump power amplifier pump source, the pump power of the remote pump power amplifier pump source is greater than 32.8dBm;
[0058] A transmission optical fiber segment, one end of which is connected to a remote pump amplifier pump source;
[0059] a first noise suppressor, the first noise suppressor being connected to the other end of the transmission optical fiber segment;
[0060] A combiner, wherein the input end of the combiner comprises at least two channels, one of which is connected to the first noise suppressor, and the other is used to connect to the signal optical fiber; and
[0061] An erbium-doped fiber amplifier is connected to the output end of the combiner.
[0062] Optionally, the transmission optical fiber segment includes:
[0063] A second noise suppressor is connected between every two adjacent sub-optical fibers in the multiple sections of sub-optical fibers.
[0064] Optionally, the sum of the lengths of the multiple sections of sub-optical fibers is equal to the length of the signal optical fiber.
[0065] Optionally, the number of the second noise suppressors is 2 or 3.
[0066] It should be noted that when the number of the second noise suppressors reaches 4 or more, the pumping effect will also be reduced due to the attenuation of the noise suppressors themselves.
[0067] Optionally, the pump power of the remote pump power amplifier pump source is 36.6dBm-37.5dBm. A pump power of 37.5dBm of the remote pump power amplifier pump source will bring about an optimal pump gain.
[0068] Optionally, the maximum carrying power of the second noise suppressor closest to the remote pump power amplifier pump source is greater than the maximum carrying power of other second noise suppressors. The second noise suppressor closest to the remote pump power amplifier pump source needs to have a strong high-power bearing performance, otherwise, due to the increase in the pump power of the remote pump power amplifier pump source of the present invention, the second noise suppressor is easily damaged.
[0069] Optionally, the distances of each sub-fiber are equal.
[0070] Optionally, the first noise suppressor is used to remove the laser effect caused by the combination of stimulated Raman scattering and double Rayleigh scattering in the transmission fiber section.
[0071] The technical solution of the present invention further provides a non-relay optical fiber transmission system, including a remote pump power amplifier module.
[0072] Optionally, the remote pump power amplifier module is forward pumped or backward pumped.
[0073] This embodiment increases the pump power injected into the optical fiber after long-distance optical fiber transmission, thereby increasing the gain of the remote pump power amplifier module.
[0074] In one embodiment, the present invention provides a forward-pumped ultra-long-distance non-relay optical fiber transmission system. Figure 8 Schematic diagram of the structure of the forward-pumped ultra-long-distance non-relay optical fiber transmission system, as shown in Figure 8 As shown, the use of Raman noise suppression technology greatly increases the pump light power injected into the transmission optical fiber, thereby extending the transmission distance of the non-relay optical fiber communication system. A Raman noise suppressor is added after the remote pump power amplifier pump source to increase the pump light power injected into the remote pump module.
[0075] The use of a Raman pump noise suppressor proposed in this embodiment can effectively increase the pump power injected into the optical fiber after long-distance optical fiber transmission, thereby increasing the gain of the remote pump module and increasing the transmission distance of the non-relay communication system.
[0076] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.
Claims
1. A remote pump power amplifier module, characterized in that: include: A remote pump power amplifier pump source, wherein the pump power of the remote pump power amplifier pump source is greater than 32.8dBm; A transmission optical fiber segment, one end of which is connected to the remote pump power amplifier pump source; a first noise suppressor connected to the other end of the transmission optical fiber segment; A combiner, wherein an input end of the combiner comprises at least two channels, one of which is connected to the first noise suppressor, and the other is used to connect to a signal optical fiber; and An erbium-doped fiber amplifier is connected to the output end of the combiner.
2. The remote pump power amplifier module according to claim 1, characterized in that: The transmission optical fiber segment comprises: A plurality of sections of sub-optical fiber, wherein a second noise suppressor is connected between every two adjacent sub-optical fibers in the plurality of sections of sub-optical fiber.
3. The remote pump power amplifier module according to claim 2, characterized in that: The sum of the lengths of the multiple sections of sub-optical fibers is equal to the length of the signal optical fiber.
4. The remote pump power amplifier module according to claim 2 or 3, characterized in that: The number of the second noise suppressors is 2 or 3.
5. The remote pump power amplifier module according to claim 4, characterized in that: The pump power of the remote pump power amplifier pump source is 36.6dBm-37.5dBm.
6. The remote pump power amplifier module according to claim 4, characterized in that: The maximum carrying power of the second noise suppressor closest to the remote pump amplifier pump source is greater than the maximum carrying power of other second noise suppressors.
7. The remote pump power amplifier module according to claim 2, characterized in that: The distances between each of the sub-optical fibers are equal.
8. The remote pump power amplifier module according to claim 1, characterized in that: The first noise suppressor is used to remove the laser effect generated by the combination of stimulated Raman scattering and double Rayleigh scattering in the transmission optical fiber segment.
9. A non-relay optical fiber transmission system, characterized in that: The remote pump power amplifier module comprises any one of claims 1-8.
10. The non-relay optical fiber transmission system according to claim 9, characterized in that: The remote pump power amplifier module is forward pumped or backward pumped.