CN102055529B - Optical signal processing method, device and system - Google Patents
Optical signal processing method, device and system Download PDFInfo
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Abstract
The embodiment of the invention discloses an optical signal processing method, an optical signal processing device and an optical signal processing system, which are used for improving the transmission performance of light signals. The method disclosed in the embodiment of the invention comprises: acquiring a first optical signal within a preset wavelength range from optical signals generated by a gain medium; and performing class integration treatment of the first optical signal to obtain a first control optical signal to increase the damping coefficient of a full-light gain control circuit. The embodiment of the invention also provides an optical signal processing device and an optical signal processing system. The embodiment of the invention can effectively improve the transmission performance of optical signals.
Description
Technical Field
The present invention relates to the field of signal processing, and in particular, to a method, an apparatus, and a system for processing an optical signal.
Background
In recent years, Fiber To The home (FTTx, Fiber To The x) construction has been gradually started. FTTx is a generic term for Fiber To The Building (FTTB), Fiber To The Cabinet (FTTC), and Fiber To The Home (FTTH).
The main idea of FTTx is to use optical fiber instead of the former copper wire to connect the access points. The mainstream technology is Passive Optical Network (PON), and currently, there are mainly two types of Ethernet Passive Optical Networks (EPON) and Gigabit-capable Passive Optical networks (GPON).
The PON system is mainly characterized in that a passive Optical Distribution Network (ODN) is provided between the access point and the aggregation point, thereby reducing intermediate sites. In order to adapt to various network application scenarios and further reduce access points, operators have increasingly strong requirements for long-distance PONs.
The difficulty in realizing a long-distance PON currently lies in amplifying burst optical signals upstream of the PON. The optical power of these burst optical signals is discontinuous as viewed from the time axis, and at some time point, the optical power suddenly decreases to a very low value, even to zero, and then suddenly increases. There are two main ways to realize burst Optical signal amplification, one is an Optical-to-electrical (OEO) way, and the other is an all-Optical (OOO) way.
The OOO method is widely applied because the relay device is simple and low in cost, and in the OOO method, an optical Fiber Amplifier, such as an Erbium-Doped Fiber Amplifier (EDFA), a Praseodymium-Doped Fiber Amplifier (PDFA), or the like, is adopted, which is better viewed due to its large gain, high output power, low cost, and the like.
The main problem of using fiber amplifiers to amplify burst optical signals is how to suppress transient effects. Due to the mechanism of the optical fiber amplifier, the transient state particle lifetime is in millisecond level, and the interval and length of the burst optical signal in the PON are in nanosecond-microsecond level, so that the burst optical signal amplified by the optical fiber amplifier is easy to have transient effect, and compared with the shorter burst optical signal, the power adjustment time is too long, which is not beneficial to receiving by a burst receiver, and an optical signal processing method provided in the prior art is as follows:
the Optical signal is used for controlling, namely, an all-Optical Gain Clamp (Optical Gain Clamp), the scheme uses the Optical signal to control the stability of the Optical amplification Gain, and the Optical Gain Clamp scheme uses a feedback loop method to generate control laser (possibly a plurality of) laser. Because the control laser and the burst light signal consume the upper energy level particle number together, the upper energy level particle number which can be obtained by the signal light can be quickly adjusted by the cancellation, so that the gain of the signal light with different wavelengths is kept at a certain value within a certain input power range. Therefore, the Optical GainClamp can realize rapid automatic control.
However, the above-mentioned prior art has some problems as follows:
in the Optical Gain Clamp scheme, special attention needs to be paid to selecting the wavelength of the control laser, and if the wavelength of the control laser is far away from the wavelength of the burst Optical signal, the control laser cannot control the Gain of the burst Optical signal due to the effect of the Hole Burning effect (SHB) of the Optical fiber amplifier, so that the transmission of the Optical signal is affected.
When the control laser wavelength is selected to be closer to the burst optical signal, the influence of the SHB can be weakened, but at the moment, the phenomena of overshoot and oscillation can be formed, the receiving of the burst receiver can be seriously influenced, and the transmission of the optical signal is influenced.
Disclosure of Invention
Embodiments of the present invention provide an optical signal processing method, apparatus, and system, which can ensure performance of optical signal transmission, including reliability and gain stability, on the premise of implementing burst optical signal amplification.
The optical signal processing method provided by the embodiment of the invention comprises the following steps: obtaining a first optical signal within a preset wavelength range from an optical signal generated by a gain medium; and carrying out similar integration processing on the first optical signal to obtain a first control optical signal, so that the damping coefficient of the all-optical gain control loop is increased.
The optical signal processing device provided by the embodiment of the invention comprises: a wavelength selection unit and a class integration unit; the wavelength selection unit is used for selecting a first optical signal in a preset wavelength range from optical signals generated by the gain medium and outputting the first optical signal to the similar integration unit; the quasi-integration unit is used for performing quasi-integration processing on the first optical signal to obtain a first control optical signal, so that the damping coefficient of the all-optical gain control loop is increased.
The optical signal processing system provided by the embodiment of the invention comprises: a first device, a second device, and a third device; the first device is used for generating a first working optical signal carrying service information; the second device is used for receiving the second working optical signal and amplifying the second working optical signal to form a third working optical signal, wherein the second working optical signal is formed by transmitting the first working optical signal through a line optical fiber; the third device is configured to receive the fourth working optical signal, where the fourth working optical signal is formed by transmitting a third working optical signal through a line optical fiber; the second device at least comprises an optical signal processing device.
The optical signal amplification system provided by the embodiment of the invention comprises: the device comprises a wavelength selection unit, a quasi-integration unit and a gain medium; the wavelength selection unit is used for selecting a first optical signal in a preset wavelength range from optical signals generated by the gain medium and outputting the first optical signal to the similar integration unit; the quasi-integration unit is configured to perform quasi-integration processing on the first optical signal to obtain a first control optical signal, increase a damping coefficient of the all-optical gain control loop, and input the first control optical signal to the gain medium; the gain medium is used for controlling the amplification of the input optical signal according to the first control optical signal.
According to the technical scheme, the embodiment of the invention has the following advantages:
in this embodiment, the selected first optical signal may be subjected to a class integration process by the class integration unit, so that a damping coefficient of the all-optical gain control loop is increased, and after the damping coefficient is increased, overshoot or oscillation may be reduced or eliminated, so that in this embodiment, a wavelength of the control laser that is closer to a wavelength of the burst optical signal may be selected, and overshoot or oscillation may be reduced or eliminated by the class integration unit, so that stability of an optical signal gain may be ensured on the premise of realizing amplification of the burst optical signal;
secondly, the quasi-integral unit in the embodiment is composed of a passive optical device, gain control is performed in an optical layer, a pump laser does not need to be adjusted, and control is simple and reliable;
again, the technical solution of this embodiment may also be used for gain control when amplifying a continuous optical signal, for example, for gain control when amplifying an optical signal in a Wavelength Division Multiplexing (WDM) network, and mainly can suppress transient effects caused by sudden changes in optical signal power (for example, increasing a wavelength or decreasing a wavelength).
Drawings
FIG. 1 is a schematic diagram of an embodiment of an optical signal processing method according to an embodiment of the present invention;
FIG. 2 is a schematic diagram of another embodiment of an optical signal processing method according to the embodiment of the present invention;
FIG. 3 is a diagram of an optical signal processing method according to another embodiment of the present invention;
FIG. 4 is a schematic diagram of an embodiment of an optical signal amplification system according to an embodiment of the present invention;
FIG. 5 is a schematic diagram of an optical signal amplification system according to another embodiment of the present invention;
FIG. 6 is a schematic diagram of an optical signal amplification system according to yet another embodiment of the present invention;
FIG. 7 is a schematic diagram of an optical signal amplifying system according to another embodiment of the present invention;
fig. 8 is a schematic diagram of an optical signal processing system according to an embodiment of the present invention.
Detailed Description
Embodiments of the present invention provide an optical signal processing method, apparatus, and system, which can ensure performance of optical signal transmission on the premise of implementing burst optical signal amplification.
Referring to fig. 1, an embodiment of an optical signal processing method according to the embodiment of the present invention includes:
101. obtaining a first optical signal within a preset wavelength range from an optical signal generated by a gain medium;
in this embodiment, the first optical signal may be used to generate a first control optical signal to process the input optical signal.
The gain medium may be a variety of fiber gain media, such as erbium doped fiber or praseodymium doped fiber, or may be a waveguide type gain medium, etc.
In this embodiment, similar to the all-optical gain clamping method, there are many methods for obtaining the first optical signal in the preset range from the optical signal generated by the gain medium, for example, the wavelength selection unit may filter a part of the optical signal from the forward output light of the gain medium as the first signal light, or the wavelength selection unit may filter a part of the optical signal from the reverse output light of the gain medium as the first signal light. Meanwhile, the wavelength selection unit and the gain medium do not need to be directly connected, and some other optical devices, such as a wavelength division multiplexer for incorporating pump light, etc., may be inserted between the wavelength selection unit and the gain medium.
In this embodiment, the main function of the wavelength selection unit is to obtain the first optical signal, and the specific implementation manner may be various, for example, the first optical signal may be implemented by a filter, or implemented by a circulator and a filter, or implemented by a grating and a circulator, and so on. The implementation of the wavelength selection unit is similar to the method for selecting control lasers in the conventional known all-Optical Gain clamping (Optical Gain Clamp) method, except that in the embodiment corresponding to the present invention, the wavelength selection unit selects the first Optical signal in a predetermined wavelength range, for example, in this embodiment, the first Optical signal may be a set of lasers in a predetermined wavelength range, and the method for all-Optical Gain clamping selects 1 to 2 control lasers. Therefore, in this embodiment, the wavelength range selected by the wavelength selection unit may be wider than the wavelength range selected by the device implementing similar function in all-optical gain clamping.
102. And carrying out similar integration processing on the first optical signal to obtain a first control optical signal.
After the first optical signal is acquired, the first optical signal may be input to a similar integration unit for performing a similar integration process, so as to obtain a first control optical signal.
In this embodiment, in the process of inputting the first optical signal into the quasi-integration unit for quasi-integration processing, the damping coefficient of the all-optical gain control loop may be increased, so as to reduce or eliminate overshoot and oscillation on the amplified burst optical signal.
In this embodiment, after obtaining the first control Optical signal, the input Optical signal may be processed according to the first control Optical signal, and in practical applications, after obtaining the first control Optical signal, the amplification of the input Optical signal may be controlled by using the first control Optical signal, for example, by a method similar to an all-Optical Gain Clamp (Optical Gain Clamp), and a specific control procedure is common knowledge of those skilled in the art, and is not limited herein.
It is understood that, in this embodiment, in addition to controlling the amplification of the input optical signal according to the first control optical signal, other forms of processing may be performed on the input optical signal, and the specific processing manner is not limited herein.
The input Optical signal in this embodiment may be a Burst Optical signal (e.g., Optical Burst or Optical packet) or a continuous Optical signal (e.g., an Optical signal in a WDM network).
In this embodiment, the selected first optical signal may be subjected to a class integration process by the class integration unit, so that a damping coefficient of the all-optical gain control loop is increased, and after the damping coefficient is increased, overshoot or oscillation on the amplified burst optical signal may be reduced or eliminated, so that in this embodiment, a wavelength of the control laser closer to a wavelength of the burst optical signal may be selected, and overshoot or oscillation is eliminated or reduced by the class integration unit, so that stability of an optical signal gain may be ensured on the premise of realizing amplification of the burst optical signal;
secondly, the quasi-integral unit in the embodiment is composed of passive devices, the gain control is performed in the optical layer,
the pump laser does not need to be quickly adjusted, and the control is simple and reliable;
again, the technical solution of this embodiment may also be used for gain control when amplifying a continuous optical signal, for example, for gain control when amplifying an optical signal in a WDM network, and may mainly suppress transient effects caused by power changes of the optical signal (for example, increasing a wavelength or decreasing a wavelength).
Referring to fig. 2, a method for processing an optical signal according to an embodiment of the present invention is described in detail below according to different implementations of a class integration unit, where another embodiment of the method for processing an optical signal according to the present invention includes:
201. obtaining a first optical signal within a preset wavelength range through a wavelength selection unit;
in this embodiment, the first optical signal may be used to generate a first control optical signal to process the input optical signal.
The gain medium may be a variety of fiber gain media, such as erbium doped fiber or praseodymium doped fiber, or may be a waveguide type gain medium, etc.
In this embodiment, similar to the all-optical gain clamping method, there are many methods for obtaining the first optical signal in the preset range from the optical signal generated by the gain medium, for example, the wavelength selection unit may filter a part of the optical signal from the forward output light of the gain medium as the first signal light, or the wavelength selection unit may filter a part of the optical signal from the reverse output light of the gain medium as the first signal light. Meanwhile, the wavelength selection unit and the gain medium do not need to be directly connected, and some other optical devices, such as a wavelength division multiplexer for incorporating pump light, etc., may be inserted between the wavelength selection unit and the gain medium.
In this embodiment, the main function of the wavelength selection unit is to obtain the first optical signal, and the specific implementation manner may be various, for example, the first optical signal may be implemented by a filter, or implemented by a circulator and a filter, or implemented by a grating and a circulator, and so on. The implementation of the wavelength selection unit is similar to a method for selecting control lasers in a conventional known all-Optical Gain clamping (Optical Gain Clamp) method, except that in the embodiment corresponding to the present invention, the wavelength selection unit selects a first Optical signal in a predetermined wavelength range, for example, in this embodiment, the first Optical signal may be a group of lasers, and 1 to 2 control lasers are selected in the all-Optical Gain clamping method. Therefore, in this embodiment, the wavelength range selected by the wavelength selection unit may be wider than the wavelength range selected by the device implementing similar function in all-optical gain clamping.
Referring to fig. 4, when the wavelength selection unit is a filter, the optical signal on the main optical path passes through the combiner, the wavelength division multiplexer, the gain medium, and the filter. The filter can select an optical signal in a certain wavelength range, for example, the wavelength is in the range of 1 nm to 2 nm, from the main optical path as a first optical signal according to actual requirements;
referring to fig. 5, when the wavelength selection unit is a grating and a circulator, the optical signal on the main optical path passes through the combiner, the wavelength division multiplexer, the gain medium, and the circulator and then reaches the grating. The grating transmits part of the optical signal, and the rest of the optical signal (for example, the optical signal with the wavelength between 1 nm and 2 nm) is reflected back to the circulator through the grating, and is output to the integrator-like unit by the circulator to form the first optical signal.
202. Inputting the first optical signal into a splitter to obtain N paths of optical signals;
in this embodiment, after obtaining the first optical signal, the first optical signal is input to the splitter of the quasi-integration unit, so as to obtain N optical signals.
203. Inputting N paths of optical signals into N different optical Fiber delay lines (FDL, Fiber delay line) respectively;
in the present embodiment, FDL is used as an example of the optical delay unit, and other types of optical delay units, such as slow optical waveguides, may also be used in practical applications, and the specific optical delay unit is not limited herein.
After obtaining N optical signals, the N optical signals may be respectively input into N different FDLs, where N is an integer greater than or equal to 2.
The lengths of the N FDLs are increased gradually, that is, the delay time of the N FDLs is increased step by step, the delay time of the first FDL is T, the delay time of the second FDL is 2T, the delay time of the third FDL is 3T, and so on.
It should be noted that the specific value of T may be determined by the rising time and/or overshoot index expected by the system, and is not limited herein, and similarly, the delay times of different FDLs do not necessarily need to be increased by integral multiple, and may also be T, 1.5T, and 3T, for example, as long as the delay times of N FDLs are gradually increased, and the specific delay time is not limited herein.
In this embodiment, different FDLs may have different resonant frequencies due to different lengths, and therefore, the pass band or reflection bandwidth of the filter or grating may be broadened to allow multiple resonant frequencies to start oscillation, so that the values of the delay of the FDLs on different branches may not need to be highly accurate, thereby reducing the cost of the FDLs.
In this embodiment, the lengths of the FDLs can be precisely controlled, so that only 1 or a few resonant frequencies are generated in the optical layer control circuit, and thus the selection bandwidth of the wavelength selection unit does not need to be set to be large.
204. Superposing the N paths of delayed optical signals by using a combiner to obtain a first control optical signal;
the combiner in the quasi-integration unit is connected with the output of each FDL, and after the combiner receives the optical signals output by the FDLs, the optical signals can be superposed.
Since the FDLs have different lengths, the time for each optical signal to reach the combiner is different, and the superposition of these optical signals is equivalent to performing a process similar to integration.
In this embodiment, after the combiner superimposes the N optical signals, it is equivalent to complete the process similar to integration of the optical signals, so as to obtain a first control optical signal, where the first control optical signal may be used to control amplification of the input optical signal.
205. The amplification of the input optical signal is controlled using a first control optical signal.
After the first control optical signal is acquired, the amplification of the input optical signal can be controlled by using the first control optical signal, and a specific control process is common knowledge of those skilled in the art and is not limited herein.
In this embodiment, the gain value of the entire all-optical gain control loop may be adjusted by attenuating the generated first control optical signal with an attenuator to obtain a second control optical signal, and controlling amplification of the input optical signal with the second control optical signal.
In order to achieve stable operation of the whole optical path, the attenuation amount of the optical signal should be the same as the gain amount of the optical signal, so that the gain value of the whole all-optical gain control loop can be adjusted according to different requirements through the attenuator.
It should be noted that the input Optical signal in this embodiment may be a Burst Optical signal (e.g., Optical Burst or Optical packet) or a continuous Optical signal (e.g., an Optical signal in a WDM network).
In this embodiment, the pump light required for amplifying the input signal may be injected after being transmitted through the line fiber by the pump laser, so that the pump laser may be located in a remote site. Of course, the pump lasers may also be located locally, injected through connecting fibers or other optical waveguides between the optical devices.
In this embodiment, the selected first optical signal may be subjected to a class integration processing by the class integration unit, so that a damping coefficient of the all-optical gain control loop is increased, and after the damping coefficient is increased, overshoot or oscillation may be reduced or eliminated, so that in this embodiment, a wavelength of the control laser that is closer to a wavelength of the burst optical signal may be selected, and overshoot or oscillation may be reduced or eliminated by the class integration unit, so that stability of optical signal gain may be ensured on the premise of realizing amplification of the burst optical signal;
secondly, the quasi-integral unit in the embodiment is composed of passive devices, gain control is performed in an optical layer, a pump laser does not need to be adjusted, and control is simple and reliable;
thirdly, the technical solution of this embodiment may also be used for gain control when amplifying a continuous optical signal, for example, for gain control when amplifying an optical signal in a WDM network, and mainly may suppress a transient effect caused by a power change of the optical signal (for example, increasing a wavelength or decreasing a wavelength);
furthermore, when the present embodiment is applied to a PON system, the light source portion of the pump light may be implemented by a remote pump located in an Optical Line Terminal (OLT), so that the transmission distance of the PON system can be extended or the splitting ratio of the PON system can be increased under the condition that an Optical Distribution Network (ODN) is continuously kept passive, thereby reducing the networking cost of the entire system.
The quasi-integration unit described in the above embodiments is composed of a splitter, N FDLs, and a combiner, and in practical applications, since there are N FDLs, a plurality of resonant frequencies may be generated in the oscillation loop. To further reduce the overshoot and oscillation of the amplified burst signal, a plurality of filters may be used to separate the resonant frequencies, and referring to fig. 3, for easy understanding, still another embodiment of the optical signal processing method according to the embodiment of the present invention includes:
301. obtaining a first optical signal within a preset wavelength range through a wavelength selection unit;
in this embodiment, the first optical signal may be used to generate a first control optical signal to process the input optical signal.
In this embodiment, the specific wavelength selection unit may be implemented by a filter, or implemented by a circulator and a filter, or implemented by a grating and a circulator.
Referring to fig. 6, when the wavelength selection unit is a filter, the optical signal on the main optical path passes through the combiner, the wavelength division multiplexer, the gain medium, and the filter can select an optical signal within a certain wavelength range, for example, a wavelength within a range of 2 nm to 10 nm, from the main optical path as a first optical signal according to actual requirements;
referring to fig. 7, when the wavelength selection unit is a grating, the optical signal on the main optical path reaches the grating after passing through the combiner, the wavelength division multiplexer, the gain medium, and the circulator, the grating will transmit a portion of the optical signal, and the remaining optical signal (e.g., the optical signal with the wavelength range of 2 nm to 10 nm) will be reflected back to the circulator through the grating, and output to the integrator-like unit by the circulator, so as to form the first optical signal.
It should be noted that the wavelength range of the first optical signal obtained in the embodiment may be larger than the wavelength range of the first optical signal obtained in the embodiment shown in fig. 2.
302. Inputting the first optical signal into a first sub-filter;
in this embodiment, after obtaining the first optical signal, the first optical signal may be input to the first sub-filter.
303. The first sub-filter selects a first sub-optical signal in a preset wavelength range from the first optical signal;
after the first optical signal is received by the first sub-filter, a first sub-optical signal in a preset wavelength range, for example, a first sub-optical signal in a wavelength range of 1 nm to 2 nm, may be selected from the first optical signal.
304. Inputting the first sub optical signal into a first Fiber Delay Line (FDL), and inputting the other optical signals left in the first optical signal into a second sub filter;
in the present embodiment, FDL is used as an example of the optical delay unit, and other types of optical delay units, such as slow optical waveguides, may also be used in practical applications, and the specific optical delay unit is not limited herein.
After the first sub-filter selects the first sub-optical signal, the first sub-optical signal may be input to the first FDL, and the other optical signals remaining in the first optical signal may be input to the second sub-filter.
305. The other sub-filters repeat similar operations;
in this embodiment, the second sub-filter to the N-1 sub-filter may perform similar operations, that is, selecting sub-optical signals with preset wavelength ranges, and inputting the remaining optical signals into the next sub-filter.
It should be noted that, after receiving the optical signals of the N-1 sub-filter, the last sub-filter, that is, the nth sub-filter, may directly input all of the optical signals to the nth FDL (which is equivalent to that the last sub-filter is not needed), or may select sub-optical signals in a preset wavelength range from the optical signals, input the selected sub-optical signals to the nth FDL, and discard the remaining optical signals.
In this embodiment, N is greater than or equal to 2, the lengths of the first optical delay line to the nth optical delay line are increased gradually, that is, the delay times of the N FDLs are increased step by step, for example, the delay time of the first FDL is T, the delay time of the second FDL is 2T, the delay time of the third FDL is 3T, and so on.
The specific value of T may be determined by the rising time and/or overshoot index expected by the system, and is not limited herein, and similarly, the delay times of different FDLs do not necessarily need to be increased by an integral multiple, and may also be T, 1.5T, or 3T, for example, as long as the delay times of N FDLs are gradually increased, and the specific delay time is not limited herein.
It should be noted that, the interval between the wavelength ranges of the optical signals selected by the first sub-filter to the nth sub-filter is greater than or equal to a preset value, so that the resonant frequency intervals are pulled apart.
306. The combiner superposes N paths of optical signals output by the N FDLs to obtain a first control optical signal;
the combiner in the quasi-integration unit is connected with the output of each FDL, and after the combiner receives the optical signals output by the FDLs, the optical signals can be superposed.
Since the FDLs have different lengths, the time for each optical signal to reach the combiner is different, and the superposition of these optical signals is equivalent to performing a process similar to integration.
In this embodiment, after the combiner superimposes the N optical signals, it is equivalent to complete the process similar to integration of the optical signals, so as to obtain a first control optical signal, where the first control optical signal may be used to control amplification of the input optical signal.
307. The amplification of the input optical signal is controlled using a first control optical signal.
After the first control optical signal is acquired, the amplification of the input optical signal can be controlled by using the first control optical signal, and a specific control process is common knowledge of those skilled in the art and is not limited herein.
In this embodiment, the attenuator may be used to attenuate the generated first control optical signal to form a second control optical signal, and the amplification of the input optical signal may be controlled by the second control optical signal.
It should be noted that the input Optical signal in this embodiment may be a Burst Optical signal (e.g., an Optical Burst or an Optical packet) or a continuous Optical signal (e.g., an Optical signal in a WDM network).
In this embodiment, the pump light required for amplifying the input signal may be injected after being transmitted through the line fiber by the pump laser, so that the pump laser may be located in a remote site. Of course, the pump lasers may also be located locally, injected through connecting fibers or other optical waveguides between the optical devices.
In this embodiment, the selected first optical signal may be subjected to a class integration processing by the class integration unit, so that a damping coefficient of the all-optical gain control loop is increased, and after the damping coefficient is increased, overshoot or oscillation may be reduced or eliminated, so that in this embodiment, a wavelength of the control laser that is closer to a wavelength of the burst optical signal may be selected, and overshoot or oscillation may be reduced or eliminated by the class integration unit, so that stability of optical signal gain may be ensured on the premise of realizing amplification of the burst optical signal;
secondly, the quasi-integral unit in the embodiment is composed of passive devices, gain control is performed in an optical layer, a pump laser does not need to be adjusted, and control is simple and reliable;
thirdly, the technical solution of this embodiment may also be used for gain control when amplifying a continuous optical signal, for example, for gain control when amplifying an optical signal in a WDM network, and mainly may suppress a transient effect caused by a power change of the optical signal (for example, increasing a wavelength or decreasing a wavelength);
furthermore, when the embodiment is applied to a PON system, the light source portion of the pump light may be implemented by a remote pump located in an Optical Line Terminal (OLT), so that the transmission distance of the PON system can be extended or the splitting ratio of the PON system can be increased under the condition that an Optical Distribution Network (ODN) is continuously kept passive, thereby reducing the networking cost of the entire system;
still further, in this embodiment, the quasi-integration unit may employ multiple sub-filters for filtering, and the interval between the wavelengths of the respective selected sub-optical signals is greater than or equal to a preset value, so that the resonant frequency interval may be pulled apart, and laser resonance on the feedback loop is more stable under a steady state condition, which is beneficial to reducing overshoot and oscillation of the amplified signal.
The optical signal processing method in the present embodiment is described in detail above, and the validity of the optical signal processing method in the present embodiment is briefly demonstrated below:
in this embodiment, at the rising edge of the burst optical signal, the gain of the optical fiber amplifier can be represented by the following formula:
G(t)=G(0)+[G(∞)-G(0)][1-exp(-t/τe)]
wherein, taue=τ0/(1+γ),τ0For a fiber amplifier to temporarily stabilize particle lifetime, the order of milliseconds, that is, the open loop response time of the fiber amplifier is roughly in the order of milliseconds.
The open-loop transfer function is subjected to Ralsberg transform, and G(s) ═ b1/s-k1/(τ) can be obtainedes +1), where b1 and k1 are coefficients and s is the lakesman.
In the prior art, the process is simplified, namely, a proportional element (assuming that the proportional coefficient is k2) is added to a feedback loop and a closed loop is formed, so that the closed loop characteristic equation is a two-order equation: s2+(1-k1k2+k2b1τe)/τe*s+k2b1/τe=0。
From many research reports and academic papers, the prior art solution is an underdamped system, and therefore overshoots and oscillations occur.
In this embodiment, an quasi-integral system (simplified processing, which is equivalent to an integral element, assuming that its transfer function is k2/(Ts +1), where k2 is a coefficient, and T is an integral element time constant, which corresponds to an optical fiber delay line delay unit in the following embodiments) is added to a feedback loop in the prior art, and finally, a third-order equation is formed by the characteristic equation of the whole closed loop:
s3+(T+τe)/τe/T*s2+(1-k1k2+k2b1τe)/τe/T*s+k2b1/τe/T=0。
according to the automatic control theory, a cathode point can be added by reasonably selecting parameters, and an original underdamping system is corrected into an over-damping system, so that overshoot and oscillation can be eliminated.
The above theoretically proves the effectiveness of the optical signal processing method in the present embodiment, and the following is verified from the perspective of simulation experiments:
simulation results show that a network application scene close to reality is adopted, in the existing all-optical gain clamping technical scheme, the overshoot of a burst signal at a receiving end can reach more than 1.3dB, and the overshoot can be effectively reduced by adopting the scheme:
when the quasi-integration link of two branches (namely two FDLs) is adopted, the overshoot is reduced to 0.9 dB; when an integration-like element of three branches (i.e., three FDLs) is used, the overshoot is reduced to 0.7 dB.
The effectiveness of the optical signal processing method in this embodiment is proved from the theoretical and practical perspectives, so that the optical signal processing method in the embodiment of the present invention can effectively reduce or even eliminate overshoot or oscillation, and thus can ensure the reliability of optical signal transmission on the premise of realizing burst optical signal amplification.
An optical signal processing apparatus in an embodiment of the present invention is described below, and the optical signal processing apparatus in the embodiment includes:
a wavelength selection unit and a class integration unit;
the wavelength selection unit is used for selecting a first optical signal in a preset wavelength range from the optical signals generated by the gain medium and outputting the first optical signal to the analog integration unit;
the analog integration unit is used for performing analog integration processing on the first optical signal to obtain a first control optical signal, so that the damping coefficient of the all-optical gain control loop is increased, and the first control optical signal can control the input optical signal.
The optical signal processing apparatus in this embodiment may further include: an attenuator;
the class integration unit sends the first control optical signal to the attenuator, the attenuator generates a second control optical signal after performing power attenuation on the first control optical signal, and the second control optical signal is used for controlling the input optical signal.
In this embodiment, the input optical signal is a burst optical signal or a continuous optical signal.
In this embodiment, the wavelength selection unit may be a filter, or the wavelength selection unit is composed of a circulator and a filter, or the wavelength selection unit is composed of a grating and a circulator.
The quasi-integration unit in this embodiment may specifically be one of the following two structures:
(1) the type of integration unit comprises:
the optical delay line comprises a splitter, N paths of optical delay units and a combiner;
the splitter is used for splitting the first optical signal to obtain N paths of optical signals, and the N paths of optical signals are respectively input into the N paths of optical delay units;
the N paths of optical delay units are used for respectively delaying the N paths of optical signals;
the combiner is used for superposing the N paths of delayed optical signals;
and N is an integer greater than or equal to 2, and the delay values of the N paths of optical delay units are increased progressively.
(2) The type of integration unit comprises:
n sub-filters, N optical delay units and a combiner;
the first sub-filter is used for selecting a first sub-optical signal in a preset wavelength range from the input first optical signal, inputting the first sub-optical signal into the first path of optical delay unit, and inputting the rest optical signal in the first optical signal into the second sub-filter;
the second sub-filter to the N-1 th sub-filter perform operations similar to the first sub-filter until optical signals remaining after the operations among the first optical signals are input to the N-th sub-filter;
the Nth sub-filter is used for inputting all the rest optical signals into the Nth optical delay unit, or the Nth sub-filter selects the Nth sub-optical signal in the preset wavelength range from the rest optical signals, inputs the Nth sub-optical signal into the Nth optical delay unit and discards other optical signals;
the combiner is used for superposing the N paths of optical signals output by the N paths of optical delay units;
and N is an integer greater than or equal to 2, and delay values from the first path of optical delay unit to the Nth path of optical delay unit are gradually increased.
It should be noted that, the optical signal processing apparatus described in the foregoing embodiment may control the input optical signal according to the first control optical signal or the second control optical signal, and the specific control manner may be: the amplification of the input optical signal may be controlled in other manners, but is not limited to this, and the following description will be given by taking the control of the amplification of the input optical signal as an example:
an embodiment of the present invention further provides an optical signal amplification system, where the optical signal amplification system specifically includes:
the device comprises a wavelength selection unit, a quasi-integration unit and a gain medium;
the wavelength selection unit is used for selecting a first optical signal in a preset wavelength range from the optical signals generated by the gain medium and outputting the first optical signal to the analog integration unit;
the analog integration unit is used for performing analog integration processing on the first optical signal to obtain a first control optical signal, so that the damping coefficient of the all-optical gain control loop is increased, and the first control optical signal is input into the gain medium;
the gain medium is used for controlling the amplification of the input optical signal according to the first control optical signal.
The optical signal amplification system in this embodiment may further include: an attenuator;
the class integration unit sends the first control optical signal to the attenuator;
the attenuator generates a second control optical signal after performing power attenuation on the first control optical signal, and inputs the second control optical signal into a gain medium;
the gain medium is used for controlling the amplification of the input optical signal according to the second control optical signal.
It should be noted that the wavelength selection unit in this embodiment may be a filter in practical application, or the wavelength selection unit may be composed of a circulator and a filter, or the wavelength selection unit may be composed of a grating and a circulator.
For convenience of understanding, the following detailed description of the optical signal amplifying system in the embodiment of the present invention is provided by four specific examples in practical application, and it is understood that, in practical application, a person skilled in the art can arbitrarily design the optical signal amplifying system based on the above wavelength selecting unit and the integration-like unit according to the common general knowledge, and the specific manner is not limited herein:
referring to fig. 4, an embodiment of an optical signal amplifying system according to an embodiment of the present invention includes:
a wavelength division multiplexer 401, a first combiner 402, a gain medium 403, a filter 404, and a quasi-integration unit 405;
a first input end of the first combiner 402 is an input end of an optical signal to be amplified by the whole optical signal amplification system, an output end of the first combiner 402 is connected with a first input end of the wavelength division multiplexer 401, and a second input end of the first combiner 402 is connected with a first control optical signal or a second control optical signal;
a second input end of the wavelength division multiplexer 401 is configured to receive the pump light, and an output end of the wavelength division multiplexer 401 is connected to an input end of the gain medium 403;
it should be noted that, in this embodiment, the wavelength division multiplexer 401 may also be before the first combiner 402, that is, a first input end of the wavelength division multiplexer 401 receives an optical signal to be amplified by the whole optical signal amplification system, a second input end of the wavelength division multiplexer 401 is configured to receive pump light, an output end of the wavelength division multiplexer 401 is connected to a first input end of the first combiner 402, a second input end of the first combiner 402 is connected to the first control optical signal or the second control optical signal, and an output end of the first combiner 402 is connected to an input end of the gain medium 403.
An output of gain medium 403 is coupled to an input of filter 404;
a first output end of the filter 404 is configured to output an output optical signal, the filter 404 selects a first optical signal within a preset wavelength range from the optical signals generated by the gain medium, and outputs the first optical signal to the quasi-integration unit 405 through a second output end of the filter 404;
the similar integration unit 405 performs similar integration processing on the first optical signal to obtain a first control optical signal, so that the damping coefficient of the all-optical gain control loop is increased, and the first control optical signal is input to the second input end of the first combiner 402.
The optical signal amplification system in this embodiment further includes: an attenuator 406;
the quasi-integration unit 405 sends the first control optical signal to the attenuator 406, and the attenuator 406 performs power attenuation on the first control optical signal to form a second control optical signal, and then outputs the second control optical signal to the second input end of the first combiner 402;
a second input terminal of the first combiner 402 is connected to the second control optical signal output by the attenuator 406 or to the first control optical signal output by the quasi-integration unit 405.
It should be noted that the pump light accessed by the wavelength division multiplexer 401 in this embodiment may be generated by a pump laser in the apparatus, and a module, that is, a pump laser module, is added in the apparatus; or pump light can be emitted by a pump laser located in another device (or another site), and then sent to the wavelength division multiplexer 401 after being transmitted by a line optical fiber.
Note that, the quasi integration unit 405 in this embodiment includes:
a splitter 4051, N optical fiber delay lines 4052, and a second combiner 4053;
the first optical signal enters a splitter 4051 to obtain N optical signals, the N optical signals are respectively input into N optical fiber delay lines 4052, the N optical fiber delay lines 4052 respectively delay the N optical signals, and the delayed N optical signals are superposed by a second combiner 4053;
n is an integer greater than or equal to 2, and the lengths of the N optical fiber delay lines 4052 are increased progressively.
In this embodiment, the class integration unit 405 may perform class integration processing on the selected first optical signal, so as to increase a damping coefficient of the all-optical gain control loop, and after the damping coefficient is increased, the overshoot or the oscillation may be reduced or eliminated.
In the above description, a technical solution of an annular cavity is described, and in practical applications, there may be more schemes of annular cavities, which are not described herein again, and in the following description, a technical solution of a linear cavity is described, and similarly, in practical applications, there may be more schemes of linear cavities, which are not described herein again, please refer to fig. 5, and another embodiment of the optical signal amplification system in the embodiment of the present invention includes:
a wavelength division multiplexer 501, a first combiner 502, a gain medium 503, a circulator 504, a grating 505 and a quasi-integration unit 506;
the first input terminal of the first combiner 502 is the optical signal to be amplified by the whole optical signal amplifying system
An input terminal, an output terminal connected to a first input terminal of the wavelength division multiplexer 501, a second input terminal of the first combiner 502
The two input ends are accessed with a first control optical signal or a second control optical signal;
a second input end of the wavelength division multiplexer 501 is used for receiving the pump light, and an output end of the wavelength division multiplexer 501 is connected with an input end of the gain medium 503;
it should be noted that, in this embodiment, the wavelength division multiplexer 501 may also be before the first combiner 502, that is, a first input end of the wavelength division multiplexer 501 receives an optical signal to be amplified by the whole optical signal amplification system, a second input end of the wavelength division multiplexer 501 is configured to receive pump light, an output end of the wavelength division multiplexer 501 is connected to a first input end of the first combiner 502, a second input end of the first combiner 502 is connected to the first control optical signal or the second control optical signal, and an output end of the first combiner 502 is connected to an input end of the gain medium 503.
The output of the gain medium 503 is connected to the first port of the circulator 504;
the second port of circulator 504 is connected to the first port of grating 505; the grating 505 is used for outputting an output optical signal; the grating 505 is further configured to select a first optical signal within a preset wavelength range from the optical signals generated by the gain medium, output the first optical signal to the second port of the circulator 504, and output the first optical signal to the quasi-integration unit 506 through the third port of the circulator 504;
the quasi-integration unit 506 performs quasi-integration processing on the first optical signal to obtain a first control optical signal, so that the damping coefficient of the all-optical gain control loop is increased, and the first control optical signal is input to the second input end of the first combiner 502.
The optical signal amplification system in this embodiment may further include: an attenuator 507;
the quasi-integration unit 506 sends the first control optical signal to the attenuator 507, and the attenuator 507 performs power attenuation on the first control optical signal to form a second control optical signal, and then outputs the second control optical signal to the second input end of the first combiner 502;
a second input end of the first combiner 502 is connected to the second control optical signal output by the attenuator 507 or directly connected to the first control optical signal output by the quasi-integration unit 506.
It should be noted that the pump light accessed by the wavelength division multiplexer 501 in this embodiment may be generated by a pump laser in the apparatus, and a module, that is, a pump laser module, is added in the apparatus; or pump light can be emitted by a pump laser located in another device (or another site), and then sent to the wavelength division multiplexer 501 after being transmitted by a line optical fiber.
The quasi-integration unit 506 in this embodiment includes:
a splitter 5061, an N-way optical fiber delay line 5062, and a second combiner 5063;
the first optical signal enters a splitter 5061 to obtain N optical signals, the N optical signals are respectively input into N optical fiber delay lines 5062, the N optical fiber delay lines 5062 respectively delay the N optical signals, and the delayed N optical signals are superposed by a second combiner 5063;
n is an integer greater than or equal to 2, and the lengths of the N optical fiber delay lines 5062 are increased progressively.
In this embodiment, the class integration unit 506 may perform class integration processing on the selected first optical signal, so as to increase a damping coefficient of the all-optical gain control loop, and after the damping coefficient is increased, the overshoot or the oscillation may be reduced or eliminated.
Referring to fig. 6, the similar integration unit described in the two embodiments includes a splitter, N FDLs, and a combiner, and according to the description of the foregoing method embodiments, similarly, the similar integration unit may include N sub-filters, N FDLs, and a combiner, where a further embodiment of the optical signal amplification system in the embodiment of the present invention includes:
a wavelength division multiplexer 601, a first combiner 602, a gain medium 603, a filter 604, and a quasi-integration unit 605;
a first input end of the first combiner 602 is an input end of an optical signal to be amplified by the whole optical signal amplification system, an output end of the first combiner is connected with a first input end of the wavelength division multiplexer 601, and a second input end of the first combiner 602 is connected with a first control optical signal or a second control optical signal;
a second input end of the wavelength division multiplexer 601 is used for receiving the pump light, and an output end of the wavelength division multiplexer 601 is connected with an input end of the gain medium 603;
it should be noted that, in this embodiment, the wavelength division multiplexer 601 may also be before the first combiner 602, that is, a first input end of the wavelength division multiplexer 601 receives an optical signal to be amplified by the entire optical signal amplification system, a second input end of the wavelength division multiplexer 601 is configured to receive pump light, an output end of the wavelength division multiplexer 601 is connected to a first input end of the first combiner 602, a second input end of the first combiner 602 is connected to the first control optical signal or the second control optical signal, and an output end of the first combiner 602 is connected to an input end of the gain medium 603.
The output terminal of the gain medium 603 is connected to the input terminal of the filter 604;
a first output end of the filter 604 is configured to output an output optical signal, the filter 604 selects a first optical signal within a preset wavelength range from the optical signals generated by the gain medium, and outputs the first optical signal to the quasi-integration unit 605 through a second output end of the filter 604;
the similar integration unit 605 performs similar integration processing on the first optical signal to obtain a first control optical signal, so that the damping coefficient of the all-optical gain control loop is increased, and the first control optical signal is input to the second input end of the first combiner 602.
The optical signal amplification system in this embodiment further includes: an attenuator 606;
the quasi-integration unit 605 sends the first control optical signal to the attenuator 606, and the attenuator 606 performs power attenuation on the first control optical signal to form a second control optical signal, and outputs the second control optical signal to the second input end of the first combiner 602;
a second input end of the first combiner 602 is connected to the second control optical signal output by the attenuator 606 or directly connected to the first control optical signal output by the quasi-integration unit 605.
It should be noted that the pump light accessed by the wavelength division multiplexer 601 in this embodiment may be generated by a pump laser in the apparatus, and a module, that is, a pump laser module, is added in the apparatus; or pump light can be emitted by a pump laser located in another device (or another site), and then sent to the wavelength division multiplexer 601 after being transmitted by a line optical fiber.
Note that, the quasi integration unit 605 in this embodiment includes:
the first optical signal is input into a first sub-filter, the first sub-filter is used for selecting a first sub-optical signal in a preset wavelength range from the first optical signal, inputting the first sub-optical signal into a first optical fiber delay line, and inputting the rest other optical signals in the first optical signal into a second sub-filter;
the second sub-filter to the N-1 th sub-filter perform operations similar to the first sub-filter until the other optical signals remaining in the first optical signal are input to the nth sub-filter;
the Nth sub-filter inputs all the remaining optical signals into the Nth optical fiber delay line (at this time, the Nth sub-filter only plays a role in optical signal transmission, and can also be considered as not needing the Nth sub-filter), or the Nth sub-filter selects the Nth sub-optical signal in a preset wavelength range from the remaining optical signals, inputs the Nth sub-optical signal into the Nth optical fiber delay line, discards other optical signals, N is an integer greater than or equal to 2, and the lengths from the first optical fiber delay line to the Nth optical fiber delay line are increased progressively;
the second combiner 6053 superimposes the N optical signals output by the N optical fiber delay lines.
In this embodiment, the class integration unit 605 may perform class integration processing on the selected first optical signal, so as to increase a damping coefficient of the all-optical gain control loop, and after the damping coefficient is increased, the overshoot or the oscillation may be reduced or eliminated, so that in this embodiment, the wavelength of the control laser that is closer to the wavelength of the burst optical signal may be selected, and the overshoot or the oscillation may be reduced or eliminated by the class integration unit, so as to ensure the performance of optical signal transmission on the premise of implementing the amplification of the burst optical signal;
secondly, in this embodiment, the quasi-integration unit 605 may use a plurality of sub-filters for filtering, and the interval between the wavelengths of the respective selected sub-optical signals is greater than or equal to a preset value, so that the resonant frequency interval can be pulled apart, and the laser resonance on the feedback loop is more stable under a steady state condition, which is beneficial to reducing the overshoot and oscillation of the amplified signals.
In the above description, a technical solution of an annular cavity is described, and in practical applications, there may be more schemes of annular cavities, which are not described herein again, and in the following description, a technical solution of a linear cavity is described, and similarly, in practical applications, there may be more schemes of linear cavities, which are not described herein again, please refer to fig. 7, and another embodiment of the optical signal amplification system in the embodiment of the present invention includes:
a wavelength division multiplexer 701, a first combiner 702, a gain medium 703, a circulator 704, a grating 705 and a quasi-integration unit 706;
a first input end of the first combiner 702 is an input end of an optical signal to be amplified by the whole optical signal amplification system, an output end of the first combiner 702 is connected with a first input end of the wavelength division multiplexer 701, and a second input end of the first combiner 702 is connected with a first control optical signal or a second control optical signal;
a second input end of the wavelength division multiplexer 701 is used for receiving the pump light, and an output end of the wavelength division multiplexer 701 is connected with an input end of the gain medium 703;
it should be noted that, in this embodiment, the wavelength division multiplexer 701 may also be before the first combiner 702, that is, a first input end of the wavelength division multiplexer 701 receives an optical signal to be amplified by the entire optical signal amplification system, a second input end of the wavelength division multiplexer 701 is configured to receive pump light, an output end of the wavelength division multiplexer 701 is connected to a first input end of the first combiner 702, a second input end of the first combiner 702 is connected to the first control optical signal or the second control optical signal, and an output end of the first combiner 702 is connected to an input end of the gain medium 703.
The output end of the gain medium 703 is connected with the first port of the circulator 704;
the second port of circulator 704 is connected to the first port of grating 705; the grating 705 is used for outputting an output optical signal; the grating 705 is further configured to select a first optical signal within a preset wavelength range from the optical signals generated by the gain medium, output the first optical signal to the second port of the circulator 704, and output the first optical signal to the quasi-integration unit 706 through the third port of the circulator 704;
the quasi-integration unit 706 performs quasi-integration processing on the first optical signal to obtain a first control optical signal, so that the damping coefficient of the all-optical gain control loop is increased, and the first control optical signal is input to the second input end of the first combiner 702.
The optical signal amplification system in this embodiment may further include: an attenuator 707;
the quasi-integration unit 706 sends the first control optical signal to the attenuator 707, and the attenuator 707 performs power attenuation on the first control optical signal to form a second control optical signal, and outputs the second control optical signal to the second input end of the first combiner 702;
a second input end of the first combiner 702 is connected to the second control optical signal output by the attenuator 707 or directly connected to the first control optical signal output by the quasi-integration unit 706.
It should be noted that the pump light accessed by the wavelength division multiplexer 701 in this embodiment may be generated by a pump laser in the apparatus, and a module, that is, a pump laser module, is added in the apparatus; or pump light emitted by a pump laser located in another device (or another site) may be transmitted through a line optical fiber and then sent to the wavelength division multiplexer 701.
The class integration unit 706 in this embodiment includes:
the first optical signal is input into a first sub-filter, the first sub-filter is used for selecting a first sub-optical signal in a preset wavelength range from the first optical signal, inputting the first sub-optical signal into a first optical fiber delay line, and inputting the rest other optical signals in the first optical signal into a second sub-filter;
the second sub-filter to the N-1 th sub-filter perform operations similar to the first sub-filter until the other optical signals remaining in the first optical signal are input to the nth sub-filter;
the Nth sub-filter inputs all the remaining optical signals into the Nth optical fiber delay line (at this time, the Nth sub-filter only plays a role in optical signal transmission, and can also be considered as not needing the Nth sub-filter), or the Nth sub-filter selects the Nth sub-optical signal in a preset wavelength range from the remaining optical signals, inputs the Nth sub-optical signal into the Nth optical fiber delay line, discards other optical signals, N is an integer greater than or equal to 2, and the lengths from the first optical fiber delay line to the Nth optical fiber delay line are increased progressively;
the second combiner 7063 superimposes the N optical signals output by the N optical fiber delay lines.
In this embodiment, the class integration unit 706 may perform class integration processing on the selected first optical signal, so as to increase a damping coefficient of the all-optical gain control loop, and after the damping coefficient is increased, the overshoot or the oscillation may be reduced or eliminated, so that in this embodiment, the wavelength of the control laser that is closer to the wavelength of the burst optical signal may be selected, and the overshoot or the oscillation may be reduced or eliminated by the class integration unit, so as to ensure the performance of optical signal transmission on the premise of implementing the amplification of the burst optical signal;
secondly, in this embodiment, the quasi-integration unit 706 may employ a plurality of sub-filters for filtering, and the interval between the wavelengths of the respective selected sub-optical signals is greater than or equal to a preset value, so that the resonant frequency interval may be pulled apart, and the laser resonance on the feedback loop is more stable under a steady state condition, which is beneficial to reducing the overshoot and oscillation of the amplified signal.
It should be noted that in the above several embodiments of the optical signal amplifying system, the optical fiber delay line in the quasi-integration unit mainly functions to delay the optical signal, and therefore, other optical delay units (such as slow optical waveguide) may also be used.
Referring to fig. 8, an embodiment of an optical signal processing system according to an embodiment of the present invention is described below, where the optical signal processing system according to the embodiment of the present invention includes:
a first device 801, a second device 802, and a third device 803;
the first device 801 is configured to generate a first working optical signal carrying service information, where the first working optical signal is transmitted to the second device 802 through a line optical fiber to form a second working optical signal;
the second device 802 receives the second working optical signal, amplifies the second working optical signal to form a third working optical signal, and the third working optical signal is transmitted to the third device 803 through the line optical fiber to form a fourth working optical signal;
the third device 803 receives the fourth working optical signal;
in this embodiment, the second apparatus 802 may at least include any one of the optical signal amplification systems described in the foregoing embodiments, and the specific structure and function of the second apparatus 802 are the same as those of the optical signal amplification systems described in the foregoing embodiments, and are not described herein again.
In this embodiment, the first device 801 or the third device 803 further includes a pump laser for emitting a first pump light, the first pump light is transmitted through the line fiber and then sent to the second device 802 to form a second pump light, and the second device 802 amplifies the input optical signal by using the second pump light.
It should be noted that, the first device 801 and the second device 802 may also each include a pump laser, for example, the first device 801 includes a pump laser to emit first pump light, and the first pump light is transmitted to the second device 802 through a line fiber to form second pump light; the third device 803 also includes a pump laser, which emits a third pump light, and the third pump light is transmitted to the second device 802 through the line fiber to form a fourth pump light; the second device 802 amplifies the input optical signal by using the first pump light and the fourth pump light (i.e., the second pump light realizes forward pumping, and the fourth pump light realizes backward pumping).
In this embodiment, the second device 802 may perform a similar integration process on the selected first optical signal, so as to increase a damping coefficient of the all-optical gain control loop, and after the damping coefficient is increased, the overshoot or oscillation may be reduced or eliminated, so that the performance of optical signal transmission may be ensured on the premise of implementing the burst optical signal amplification.
It will be understood by those skilled in the art that all or part of the steps in the method for implementing the above embodiments may be implemented by hardware that is instructed to implement by a program, and the program may be stored in a computer-readable storage medium, and the above-mentioned storage medium may be a read-only memory, a magnetic disk or an optical disk, etc.
While the optical signal processing method, apparatus and system provided by the present invention have been described in detail, those skilled in the art will appreciate that the various modifications, additions, substitutions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims.
Claims (12)
1. An optical signal processing method, comprising:
obtaining a first optical signal within a preset wavelength range from an optical signal generated by a gain medium;
carrying out similar integral processing on the first optical signal to obtain a first control optical signal, so that the damping coefficient of the all-optical gain control loop is increased;
the obtaining the first control optical signal by performing a similar integration process on the first optical signal includes:
the first optical signal is divided to obtain N paths of optical signals, wherein N is an integer greater than or equal to 2;
respectively delaying the N paths of optical signals, and gradually increasing the delay time;
superposing the N paths of delayed optical signals to obtain the first control optical signal;
or,
the obtaining the first control optical signal by performing a similar integration process on the first optical signal includes:
inputting the first optical signal into a first sub-filter;
the first sub-filter selects a first sub-optical signal in a preset wavelength range from the first optical signal, inputs the first sub-optical signal into the first path of optical delay unit, and inputs the rest optical signals in the first optical signal into the second sub-filter;
the second sub-filter to the N-1 th sub-filter perform operations similar to the first sub-filter until optical signals remaining after the operations among the first optical signals are input to the N-th sub-filter;
the Nth sub-filter inputs all the rest optical signals into the Nth optical delay unit, or the Nth sub-filter selects the Nth sub-optical signal in the preset wavelength range from the rest optical signals, inputs the Nth sub-optical signal into the Nth optical delay unit and discards other optical signals; n is an integer greater than or equal to 2, and delay values from the first path of optical delay unit to the Nth path of optical delay unit are gradually increased;
and superposing all the N paths of optical signals output by the first to the Nth optical delay units to obtain the first control optical signal.
2. The method of claim 1, wherein after performing the integration-like processing on the first optical signal to obtain the first control optical signal, the method comprises:
and controlling the amplification of the input optical signal by using the first control optical signal.
3. The method of claim 1, wherein after performing the similar integration on the first optical signal to obtain the first control optical signal, the method further comprises:
performing power attenuation on the first control optical signal to generate a second control optical signal;
and controlling the amplification of the input optical signal by using the second control optical signal.
4. The method according to claim 1, wherein the delaying the N optical signals respectively specifically includes:
and respectively delaying N paths of optical signals by adopting N optical fiber delay lines, wherein delay values of the N optical fiber delay lines are increased progressively.
5. The method of claim 1, wherein the optical delay unit is a fiber optic delay line.
6. The method according to claim 2 or 3,
the pump light required for amplifying the input signal is injected after being transmitted by a pump laser through a line fiber.
7. An optical signal processing apparatus, comprising:
a wavelength selection unit and a class integration unit;
the wavelength selection unit is used for selecting a first optical signal in a preset wavelength range from optical signals generated by the gain medium and outputting the first optical signal to the similar integration unit;
the quasi-integration unit is used for performing quasi-integration processing on the first optical signal to obtain a first control optical signal, so that the damping coefficient of the all-optical gain control loop is increased;
the quasi-integration unit comprises:
the optical delay line comprises a splitter, N paths of optical delay units and a combiner;
the splitter is used for splitting the first optical signal to obtain N paths of optical signals and inputting the N paths of optical signals into the N paths of optical delay units respectively;
the N paths of optical delay units are used for respectively delaying the N paths of optical signals;
the combiner is used for superposing the N paths of delayed optical signals;
the N is an integer greater than or equal to 2, and the delay values of the N paths of optical delay units are increased progressively;
or,
the quasi-integration unit comprises:
n sub-filters, N optical delay units and a combiner;
the first sub-filter is used for selecting a first sub-optical signal in a preset wavelength range from the input first optical signal, inputting the first sub-optical signal into the first path of optical delay unit, and inputting the rest optical signals in the first optical signal into the second sub-filter;
the second sub-filter to the N-1 th sub-filter perform operations similar to the first sub-filter until optical signals remaining after the operations among the first optical signals are input to the N-th sub-filter;
the Nth sub-filter is used for inputting all the rest optical signals into the Nth optical delay unit, or the Nth sub-filter selects the Nth sub-optical signal in the preset wavelength range from the rest optical signals, inputs the Nth sub-optical signal into the Nth optical delay unit and discards other optical signals;
the combiner is used for superposing the N paths of optical signals output by the N paths of optical delay units;
and N is an integer greater than or equal to 2, and delay values from the first path of optical delay unit to the Nth path of optical delay unit are gradually increased.
8. The optical signal processing apparatus of claim 7, further comprising: an attenuator;
the attenuator is used for generating a second control optical signal after performing power attenuation on the first control optical signal obtained by the quasi-integration unit, and the second control optical signal is used for controlling amplification of the input optical signal.
9. An optical signal processing system, comprising:
a first device, a second device, and a third device;
the first device is used for generating a first working optical signal carrying service information;
the second device is used for receiving a second working optical signal and amplifying the second working optical signal to form a third working optical signal, wherein the second working optical signal is formed by transmitting a first working optical signal through a line optical fiber;
the third device is used for receiving a fourth working optical signal, and the fourth working optical signal is formed by transmitting a third working optical signal through a line optical fiber;
the second device at least comprises the optical signal processing device of any one of claims 7 to 8.
10. The optical signal processing system of claim 9, wherein the first or third device further comprises a pump laser;
the pump laser is used for emitting first pump light;
the second device is used for amplifying the input optical signal by using second pump light, and the second pump light is formed by transmitting the first pump light through a line optical fiber.
11. An optical signal amplification system, comprising:
the device comprises a wavelength selection unit, a quasi-integration unit and a gain medium;
the wavelength selection unit is used for selecting a first optical signal in a preset wavelength range from optical signals generated by the gain medium and outputting the first optical signal to the similar integration unit;
the quasi-integration unit is configured to perform quasi-integration processing on the first optical signal to obtain a first control optical signal, increase a damping coefficient of the all-optical gain control loop, and input the first control optical signal to the gain medium;
the gain medium is used for controlling the amplification of the input optical signal according to a first control optical signal;
the quasi-integration unit comprises:
the optical delay line comprises a splitter, N paths of optical delay units and a combiner;
the splitter is used for splitting the first optical signal to obtain N paths of optical signals and inputting the N paths of optical signals into the N paths of optical delay units respectively;
the N paths of optical delay units are used for respectively delaying the N paths of optical signals;
the combiner is used for superposing the N paths of delayed optical signals;
the N is an integer greater than or equal to 2, and the delay values of the N paths of optical delay units are increased progressively;
or,
the quasi-integration unit comprises:
n sub-filters, N optical delay units and a combiner;
the first sub-filter is used for selecting a first sub-optical signal in a preset wavelength range from the input first optical signal, inputting the first sub-optical signal into the first path of optical delay unit, and inputting the rest optical signals in the first optical signal into the second sub-filter;
the second sub-filter to the N-1 th sub-filter perform operations similar to the first sub-filter until optical signals remaining after the operations among the first optical signals are input to the N-th sub-filter;
the Nth sub-filter is used for inputting all the rest optical signals into the Nth optical delay unit, or the Nth sub-filter selects the Nth sub-optical signal in the preset wavelength range from the rest optical signals, inputs the Nth sub-optical signal into the Nth optical delay unit and discards other optical signals;
the combiner is used for superposing the N paths of optical signals output by the N paths of optical delay units;
and N is an integer greater than or equal to 2, and delay values from the first path of optical delay unit to the Nth path of optical delay unit are gradually increased.
12. An optical signal amplification system, comprising:
the device comprises a wavelength selection unit, an analog integration unit, an attenuator and a gain medium;
the wavelength selection unit is used for selecting a first optical signal in a preset wavelength range from optical signals generated by the gain medium and outputting the first optical signal to the similar integration unit;
the quasi-integration unit is used for performing quasi-integration processing on the first optical signal to obtain a first control optical signal, so that the damping coefficient of the all-optical gain control loop is increased;
the attenuator performs power attenuation on the first control optical signal obtained by the analog integration unit to generate a second control optical signal, and the second control optical signal is input into the gain medium;
the gain medium is used for controlling the amplification of the input optical signal according to a second control optical signal;
the quasi-integration unit comprises:
the optical delay line comprises a splitter, N paths of optical delay units and a combiner;
the splitter is used for splitting the first optical signal to obtain N paths of optical signals and inputting the N paths of optical signals into the N paths of optical delay units respectively;
the N paths of optical delay units are used for respectively delaying the N paths of optical signals;
the combiner is used for superposing the N paths of delayed optical signals;
the N is an integer greater than or equal to 2, and the delay values of the N paths of optical delay units are increased progressively;
or,
the quasi-integration unit comprises:
n sub-filters, N optical delay units and a combiner;
the first sub-filter is used for selecting a first sub-optical signal in a preset wavelength range from the input first optical signal, inputting the first sub-optical signal into the first path of optical delay unit, and inputting the rest optical signals in the first optical signal into the second sub-filter;
the second sub-filter to the N-1 th sub-filter perform operations similar to the first sub-filter until optical signals remaining after the operations among the first optical signals are input to the N-th sub-filter;
the Nth sub-filter is used for inputting all the rest optical signals into the Nth optical delay unit, or the Nth sub-filter selects the Nth sub-optical signal in the preset wavelength range from the rest optical signals, inputs the Nth sub-optical signal into the Nth optical delay unit and discards other optical signals;
the combiner is used for superposing the N paths of optical signals output by the N paths of optical delay units;
and N is an integer greater than or equal to 2, and delay values from the first path of optical delay unit to the Nth path of optical delay unit are gradually increased.
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US5892616A (en) * | 1997-01-21 | 1999-04-06 | Fujitsu Limited | Optical amplifier with reduced surge output |
CN1530729A (en) * | 2003-03-13 | 2004-09-22 | 富士通株式会社 | Light amplifier with laser light controlling function and light transmission system therewith |
CN1560695A (en) * | 2004-02-16 | 2005-01-05 | 中国科学院上海光学精密机械研究所 | Monitoring device for gain characteristic of erbium-doped fiber amplifier |
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US5892616A (en) * | 1997-01-21 | 1999-04-06 | Fujitsu Limited | Optical amplifier with reduced surge output |
CN1530729A (en) * | 2003-03-13 | 2004-09-22 | 富士通株式会社 | Light amplifier with laser light controlling function and light transmission system therewith |
CN1560695A (en) * | 2004-02-16 | 2005-01-05 | 中国科学院上海光学精密机械研究所 | Monitoring device for gain characteristic of erbium-doped fiber amplifier |
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