WO2015180006A1

WO2015180006A1 - Method and apparatus for processing optical signal

Info

Publication number: WO2015180006A1
Application number: PCT/CN2014/078373
Authority: WO
Inventors: 王轲; 李良川
Original assignee: 华为技术有限公司
Priority date: 2014-05-26
Filing date: 2014-05-26
Publication date: 2015-12-03
Also published as: CN106464382A; CN106464382B

Abstract

The present invention relates to the technical field of optical communications. Disclosed are a method and apparatus for processing an optical signal. In the solution, a multi-carrier generation apparatus generates a multi-carrier signal based on a single optical source, an offset amount of a frequency of a first path of sub-carrier signal is equal to an offset amount of a frequency of a second path of sub-carrier signal, and a frequency interval between the first path of sub-carrier signal and the second path of sub-carrier signal is known; therefore, an actual frequency interval between the first path of sub-carrier signal and the second path of sub-carrier signal is calculated; or an offset amount between the actual frequency interval and a predetermined frequency interval of the first path of sub-carrier signal and the second path of sub-carrier signal is calculated. Therefore, the problems of low accuracy and influencing the performance of an optical communication system existing in a processing process of an optical signal currently are solved.

Description

Method and device for processing optical signal

Technical field

The present invention relates to the field of optical communication technologies, and in particular, to a method and an apparatus for processing an optical signal.

Background technique

With the emergence of bandwidth data application services, such as high-bandwidth data services such as IP (Internet Protocol) Video, high transmission requirements are imposed on the transmission rates of the metropolitan area network and the backbone network, and the optical fiber has the advantage of low loss. It is widely used to increase the transmission rate. With the development of modern science and technology, especially driven by the development of communication technology, optical communication systems have developed a single-wave 100Gb/s transmission rate. The future trend of optical communication development is to realize high-speed communication systems with Flexgrid. Further increased needs, such as achieving 400 Gb/s or lTb/s. At present, the industry mainly uses laser arrays to increase the transmission rate. For example, each of the laser arrays with 10 lasers transmits optical signals at a transmission rate of 100 Gb/s, thereby achieving a transmission rate of 1 Tb/s. In practical applications, if there is overlap between optical signals emitted by different lasers, there will be interference between the optical signals, which in turn affects the accurate reception of the receiver. Therefore, in order to avoid interference between optical signals emitted by different lasers, the laser array When the optical signal is emitted, the interval between the frequencies of the optical signals emitted by any two adjacent lasers is greater than a preset value. However, the frequency of the optical signal emitted by the laser will drift during transmission. For example, the laser itself may cause the beam to drift due to the illuminating mechanism, the random drift caused by the vibration of the laser and the environment, and the external transmission environment in the optical signal transmission path (around Changes in the temperature, pressure, humidity, vibration, etc. of the environment cause instability of the state of the transmission system, causing interference between optical signals emitted by different lasers, affecting system performance. In order to avoid the influence of the frequency of the optical signal emitted by the laser during the transmission process on the performance of the optical communication system, there is a method for processing the optical signal in the prior art, and the result obtained by the method is between the optical signals. The spacing is adjusted, the method will be each of the laser arrays The frequency of the optical signal emitted by the laser is measured, and the frequency interval between the optical signals emitted by the adjacent lasers is adjusted according to the measured frequency of the optical signal emitted by each laser, and the method is specifically: The signal and the signal to be measured pass through the beam splitter, the fixed mirror and the movable mirror respectively to form a photocurrent in the photodiode, and the actual frequency after the offset of the optical signal to be measured can be calculated according to the frequency of the reference optical signal.

However, since the accuracy of the frequency of the optical signal to be measured is related to the accuracy of the frequency of the reference optical signal, and the accuracy of the frequency of the reference optical signal is limited, the accuracy of the calculated frequency interval of the optical signal is low. Further, when the frequency interval between the optical signals is adjusted according to the calculated frequency interval of the optical signal with poor accuracy, there is a defect that affects the performance of the optical communication system. Therefore, the current optical signal processing method is accurate. Low performance and defects affecting the performance of optical communication systems. Summary of the invention

Embodiments of the present invention provide a method and apparatus for processing an optical signal, which are used to solve the defects in the current process of processing an optical signal, and the defects affecting the performance of the optical communication system.

The specific technical solutions provided by the embodiments of the present invention are as follows:

In a first aspect, an apparatus for processing an optical signal includes:

a multi-carrier generating device for generating a multi-carrier signal based on a single light source;

Mixing and photoelectric conversion means for mixing the first optical signal transmitted by the received laser array with the first subcarrier signal of the multicarrier signal, and using the second of the multicarrier signals The path subcarrier signal mixes the received second optical signal emitted by the laser array; and converts the mixed first optical signal and the mixed second optical signal into the first by photoelectric conversion One way electrical signal and the second electrical signal;

And an analog-to-digital conversion device, configured to convert the first electrical signal and the second electrical signal into a first digital signal and a second digital signal respectively by analog-to-digital conversion;

Processing means, configured to: according to the first digital signal, the second digital signal, a frequency interval between the first subcarrier signal and the second subcarrier signal, and the first optical signal and Calculating the first optical signal and the predetermined frequency interval between the second optical signals Or the actual frequency interval of the second optical signal; or, according to the first digital signal, the second digital signal, and a frequency interval between the first subcarrier signal and the second subcarrier signal, An offset between an actual frequency interval of the first optical signal and the second optical signal and a predetermined frequency interval is calculated.

With reference to the first aspect, in a first possible implementation, the multi-carrier generating apparatus is specifically configured to:

A multi-carrier signal is generated based on a single source using a frequency offset lock.

With reference to the first possible implementation of the first aspect, in a second possible implementation, the multi-carrier generating apparatus is specifically configured to:

Generating a multi-carrier signal based on a single source and cascaded phase or amplitude modulator; or

Multi-carrier signals are generated based on a mode-locked fiber laser and a nonlinear medium.

With reference to the first aspect, or the first to second possible implementation manners of the first aspect, in a third possible implementation, the mixing and photoelectric conversion device is a photodiode; or the mixing and The photoelectric conversion device includes a mixer and a photodiode.

With reference to the first aspect, or the first to third possible implementation manners of the first aspect, in a fourth possible implementation, the processing apparatus is specifically configured to:

And calculating, according to the first digital signal and the second digital signal, a frequency offset of the first optical signal and a frequency f _LO1 of the first subcarrier signal by using a Viterbi & Viterbi frequency offset estimation algorithm Fi+fLOi , and calculating the sum of the frequency offset f _q of the second optical signal and the frequency f _LOq of the second subcarrier signal f _q +f _q ;

According to the + ₀₁ , the f _q +fL _0q , a frequency interval f q-fL _0l between the first subcarrier signal and the second subcarrier signal, and the first optical signal and the Calculating an actual frequency interval between the first optical signal and the second optical signal, or according to the + ₀₁ , the f _q +fL _0q , Calculating an actual frequency interval between the first path optical signal and the second path optical signal and a predetermined frequency interval by using a frequency interval _fq- f _i between the first path subcarrier signal and the second path subcarrier signal The offset between.

In combination with the first aspect, or the first to fourth possible implementations of the first aspect, at the fifth In a possible implementation manner, the processing device is any one of a processor, a field programmable gate array FPGA, a central processing unit CPU, and an application specific integrated circuit ASIC.

With reference to the first aspect, or the first to fifth possible implementation manners of the first aspect, in a sixth possible implementation, the processing apparatus is further configured to:

When the actual frequency interval is different from the predetermined frequency interval, an interval adjustment command for correcting the frequency interval deviation is issued according to the actual frequency interval and the predetermined frequency interval, or when the offset is not equal to zero And issuing an interval adjustment command for correcting the frequency interval deviation according to the offset;

The apparatus further includes frequency interval adjusting means for tuning a transmission frequency of the first laser and/or the second laser according to the interval adjustment command, the first laser transmitting the first path in the laser array a laser of an optical signal, the second laser being a laser that emits the second optical signal in the laser array.

With reference to the first aspect, or the first to the sixth possible implementation manners of the first aspect, in a seventh possible implementation, the frequency interval between the optical signals emitted by the laser array is the multi-carrier generation An integer multiple of the frequency spacing between the multicarrier signals produced by the device.

In a second aspect, a method for processing an optical signal is provided, including:

Generating a multi-carrier signal based on a single light source;

Mixing the first optical signal transmitted by the received laser array with the first subcarrier signal of the multicarrier signal, and using the second subcarrier signal of the multicarrier signal to receive the received Mixing the second optical signal emitted by the laser array for mixing;

Converting the mixed first optical signal and the mixed second optical signal into a first electrical signal and a second electrical signal by photoelectric conversion;

Converting the first road electrical signal and the second road electrical signal into a first digital signal and a second digital signal respectively by analog-to-digital conversion;

And a frequency interval between the first digital signal, the second digital signal, the first subcarrier signal and the second subcarrier signal, and the first optical signal and the second path Calculating the first optical signal and the second optical signal with a predetermined frequency interval between optical signals Or calculating an actual frequency interval; or calculating the number according to the first digital signal, the second digital signal, and a frequency interval between the first subcarrier signal and the second subcarrier signal An offset between an actual frequency interval of the optical signal and the second optical signal and a predetermined frequency interval.

With reference to the second aspect, in a first possible implementation, the generating a multi-carrier signal based on a single light source includes:

With reference to the first possible implementation manner of the second aspect, in a second possible implementation manner, the using the frequency offset locking manner to generate a multi-carrier signal includes:

With reference to the second aspect, or the first to second possible implementation manners of the second aspect, in a third possible implementation manner, the determining, according to the first digital signal, the second digital signal, Calculating the first optical signal by using a frequency interval between the first subcarrier signal and the second subcarrier signal, and a predetermined frequency interval between the first optical signal and the second optical signal And an actual frequency interval of the second optical signal; or, according to the first digital signal, the second digital signal, and between the first subcarrier signal and the second subcarrier signal The frequency interval is calculated, and the offset between the actual frequency interval of the first optical signal and the second optical signal and the predetermined frequency interval is calculated, which specifically includes:

And calculating, according to the first digital signal and the second digital signal, a frequency offset of the first optical signal and a frequency f _LO1 of the first subcarrier signal by using a Viterbi & Viterbi frequency offset estimation algorithm Fi+fLOi , and calculating the sum of the frequency offset f _q of the second optical signal and the frequency f _LOq of the first subcarrier signal f _q +f _q ;

According to the + ₀₁ , the f _q +fL _0q , a frequency interval f q-fL _0l between the first subcarrier signal and the second subcarrier signal, and the first optical signal and the Calculating an actual frequency interval between the first optical signal and the second optical signal, or according to the + ₀₁ , the f _q +fL _0q , The first subcarrier signal and the Sub-carrier signal between the second frequency interval f _q -f _i, calculating the offset distance between the actual frequency of the first frequency interval with a predetermined path and said second optical signal path of the light signal.

With reference to the second aspect, or the first to third possible implementation manners of the second aspect, the method further includes:

And adjusting a transmission frequency of the first laser and/or the second laser to correct a frequency interval deviation according to the actual frequency interval and the predetermined frequency interval when the actual frequency interval is different from the predetermined frequency interval;

Or, when the offset is not equal to zero, according to the offset, tuning a transmission frequency of the first laser and/or the second laser to correct a frequency interval deviation;

The first laser is a laser that emits the first optical signal in the laser array, and the second laser is a laser that emits the second optical signal in the laser array.

With reference to the second aspect, or the first to fourth possible implementation manners of the second aspect, in a fifth possible implementation, the frequency interval between the optical signals emitted by the laser array is the multi-carrier signal An integer multiple of the frequency interval between.

The beneficial effects of the present invention are as follows:

In the prior art, when calculating the frequency interval between two optical signals, the frequency of the optical signal of the frequency to be measured is calculated by referring to the frequency of the optical signal. Since the accuracy of the frequency of the reference optical signal is limited, therefore, The calculated accuracy of the frequency interval of the optical signal is low, and then the frequency interval between the optical signals is adjusted according to the calculated frequency interval of the optical signal with lower accuracy, which may affect the performance of the optical communication system. Therefore, the current optical signal processing method has the disadvantages of low accuracy and affects the performance of the optical communication system. In the embodiment of the present invention, an optical signal processing apparatus is provided, in which the multi-carrier generating apparatus is used. Generating a multi-carrier signal based on a single light source; mixing and photoelectric conversion means for mixing the first optical signal transmitted by the received laser array by using the first subcarrier signal in the multi-carrier signal, and using the multi-carrier The second subcarrier signal in the signal mixes the second optical signal transmitted by the received laser array; Converting the mixed first optical signal and the mixed second optical signal into a first electrical signal and a second electrical signal, respectively; and an analog to digital conversion device, configured to perform the first through analog to digital conversion Road signal and second The road electrical signal is respectively converted into a first digital signal and a second digital signal; and the processing device is configured to perform, according to the first digital signal, the second digital signal, the first subcarrier signal and the second subcarrier signal a frequency interval, and a predetermined frequency interval between the first optical signal and the second optical signal, calculating an actual frequency interval of the first optical signal and the second optical signal; or, according to the first digital signal, the second a digital signal, and a frequency interval between the first subcarrier signal and the second subcarrier signal, calculating an offset between an actual frequency interval of the first optical signal and the second optical signal and a predetermined frequency interval, In this solution, since the multi-carrier generating device generates a multi-carrier signal based on a single light source, the offset of the frequency of the first sub-carrier signal is equal to the offset of the frequency of the second sub-carrier signal, and the first path is The frequency interval between the carrier signal and the second subcarrier signal is known, and therefore, the calculated first optical signal and second optical signal are calculated. Or the frequency offset between the actual frequency interval of the first optical signal and the second optical signal and the predetermined frequency interval, thereby solving the present problem in the processing of the optical signal The accuracy is low and the performance of the optical communication system is affected. DRAWINGS

1A is a first schematic diagram of an apparatus for processing an optical signal according to an embodiment of the present invention;

FIG. 1B is a first schematic diagram of multi-carrier signal generation according to an embodiment of the present invention; FIG.

1C is a second schematic diagram of multicarrier signal generation in an embodiment of the present invention;

1D is a second schematic diagram of an apparatus for processing an optical signal according to an embodiment of the present invention;

1E is a third schematic diagram of an apparatus for processing an optical signal according to an embodiment of the present invention;

FIG. 1F is a fourth schematic diagram of an apparatus for processing an optical signal according to an embodiment of the present invention; FIG.

1G is a fifth schematic diagram of an apparatus for processing an optical signal according to an embodiment of the present invention;

1H is a schematic diagram of the number of multi-carrier signals being greater than or equal to the number of optical signals in the embodiment of the present invention; FIG. 2 is a schematic diagram showing the number of multi-carrier signals being smaller than the number of optical signals in the embodiment of the present invention; FIG. 2 is an optical signal according to an embodiment of the present invention; Process flow chart of processing;

3 is an embodiment of processing of an optical signal in an embodiment of the present invention. detailed description

The technical solutions in the embodiments of the present invention will be clearly described in conjunction with the accompanying drawings in the embodiments of the present invention. It is obvious that the described embodiments are the present invention. Some embodiments, but not all of the embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative efforts are within the scope of the present invention.

The term "and/or" in this context is merely an association that describes the associated object, indicating that there can be three relationships, for example, A and / or B, which can mean: A exists separately, and both A and B exist, exist alone B these three situations. In addition, the character " /,,, in this article, generally means that the contextual object is an "or" relationship.

In practical applications, the frequency of the optical signal emitted by the laser array is shifted, causing interference between the optical signals, thereby affecting the accuracy of the optical signal received by the receiver. In the prior art, in order to avoid optical signals. Interference occurs to calculate the frequency of the optical signal, and the frequency interval between the optical signals is controlled according to the calculated frequency. However, since the frequency of the calculated optical signal is calculated based on the frequency of the reference optical signal, the calculated light is calculated. The accuracy of the frequency interval of the signal is low, and then the frequency interval between the optical signals is adjusted according to the calculated frequency interval of the optical signal with lower accuracy, which affects the performance of the optical communication system, so the current light The signal processing method has the disadvantages of low accuracy and affects the performance of the optical communication system. In order to improve the accuracy, in the embodiment of the present invention, an optical signal interval detecting device is proposed. In this solution, the multi-carrier generating device is provided. Is based on a single source to generate a multi-carrier signal, the frequency of the first sub-carrier signal is biased The shift amount is equal to the offset of the frequency of the second subcarrier signal, and the frequency interval between the first subcarrier signal and the second subcarrier signal is known, and therefore, the calculated first path light The actual frequency interval between the signal and the second optical signal; or, the calculated offset between the actual frequency interval of the first optical signal and the second optical signal and the predetermined frequency interval, thus solving the present The accuracy of the optical signal processing is low and the performance of the optical communication system is affected.

The preferred embodiments of the present invention are described in detail below with reference to the accompanying drawings, which are to be understood And in the case of no conflict, the embodiments in the present application and the features in the embodiments can be combined with each other. Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

Referring to FIG. 1A, an embodiment of the present invention provides a first optical signal processing apparatus 100. The optical signal processing apparatus 100 includes:

a multi-carrier generating apparatus 1 configured to generate a multi-carrier signal based on a single light source;

a mixing and photoelectric conversion device 2 for mixing a first optical signal transmitted by the received laser array 3 with a first subcarrier signal in the multicarrier signal, and using a second of the multicarrier signals The path subcarrier signal mixes the received second optical signal of the laser array 3; and converts the mixed first optical signal and the mixed second optical signal into the first by photoelectric conversion Road electrical signal and second electrical signal;

The analog-to-digital conversion device 4 is configured to convert the first electrical signal and the second electrical signal into a first digital signal and a second digital signal respectively by analog-to-digital conversion;

The processing device 5 is configured to: according to the first digital signal, the second digital signal, the frequency interval between the first subcarrier signal and the second subcarrier signal, and between the first optical signal and the second optical signal a predetermined frequency interval, calculating an actual frequency interval of the first optical signal and the second optical signal; or, according to the first digital signal, the second digital signal, and the first subcarrier signal and the second subcarrier signal The frequency interval between the first and second optical signals is calculated as an offset between the actual frequency interval and the predetermined frequency interval.

In the embodiment of the present invention, since the multi-carrier generating apparatus 1 generates a multi-carrier signal based on a single light source, the offset of the frequency of the multi-carrier in the embodiment of the present invention is equal.

In the embodiment of the present invention, when the multi-carrier generating apparatus 1 generates a multi-carrier signal based on a single light source, it may be optionally generated in the following manner:

Of course, you can also use other production methods, no longer here - detailed.

In the embodiment of the present invention, when the multi-carrier generating apparatus 1 generates the multi-carrier signal by using the frequency offset locking method, optionally, the following manner may be used:

Multi-carrier signal generation based on a single source and cascaded phase or amplitude modulator (Figure 1B Show); or

A multi-carrier signal is generated based on a mode-locked fiber laser and a nonlinear medium (as shown in Figure 1C). 1B is a schematic diagram of generating a multi-carrier signal based on a single source and a cascaded phase or amplitude modulator, in which the optical signal output by the laser is first modulated by a Mach-Zehnder modulator, and the modulated optical signal is used as a subsequent stage. The input signal of the phase adjuster is modulated by the phase adjuster to output a plurality of optical carriers, and the RF signal source generates a sinusoidal clock signal with a frequency of 12.5 GHz. After passing through the electrical splitter, it is divided into two paths, one through the electric amplifier 1 Loaded onto the Mach-Zehnder modulator, the other is loaded onto the phase adjuster via the phase shifter and the electrical amplifier 2, and the amplitude of the clock signal loaded into the two modulators can be adjusted by the electric amplifier 1 and the electric amplifier 2, The phase shifter can adjust the phase difference between the two clock signals. The bias point of the Mach-Zehnder modulator can be set by the DC bias voltage, and the bias point and clock drive signal of the Mach-Zehnder modulator can be set reasonably. The amplitude, and the amplitude and phase of the phase drive's clock drive signal, can produce multiple optical loads with a frequency separation of 12.5 GHz. wave.

Figure 1C is a schematic diagram of a multi-carrier signal generated based on a mode-locked fiber laser and a non-linear medium, as is not the case in the prior art - detailed.

In the embodiment of the present invention, the mixing and photoelectric conversion device 2 can be a plurality of physical devices, for example, as shown in FIG. 1D, which may be a photodiode. In this case, the photodiode utilizes a first subcarrier signal pair in the multicarrier signal. Receiving the first optical signal emitted by the laser array 3 for mixing, and mixing the second optical signal emitted by the received laser array 3 by using the second subcarrier signal of the multicarrier signal; Converting the mixed first optical signal and the mixed second optical signal into a first electrical signal and a second electrical signal, respectively;

Alternatively, as shown in FIG. 1E, the mixing and photoelectric conversion device 2 includes a mixer and a photodiode. At this time, the mixer transmits the received laser array 3 by using the first subcarrier signal in the multicarrier signal. An optical signal is mixed, and the second optical signal transmitted by the received laser array 3 is mixed by using the second subcarrier signal in the multicarrier signal; the photodiode is first mixed by photoelectric conversion The road light signal and the mixed second light signal are respectively converted into a first road electrical signal and a second electrical signal.

Since the mixer outputs a difference frequency optical signal, the bandwidth of the mixing and photoelectric conversion device 2 can be reduced. And the sampling rate of the analog-to-digital conversion device 4, that is, at this time, the mixing and photoelectric conversion device 2 can employ the low-bandwidth mixing and photoelectric conversion device 2, and the analog-to-digital conversion device 4 can use a low sample. The analog-to-digital conversion device 4, of course, may not use a mixer. In this case, the mixing and photoelectric conversion device 2 uses a high-bandwidth mixing and photoelectric conversion device 2, and the analog-to-digital conversion device 4 uses high The analog-to-digital conversion device 4 of the sampling rate.

In the embodiment of the present invention, complicated devices using space optics and electromechanical devices are avoided, and the optical devices used are easily integrated with the laser array 3, for example, the mixing and photoelectric conversion device 2 and the like.

In the embodiment of the present invention, optionally, the processing device 5 is specifically configured to:

According to the first digital signal and the second digital signal, the Viterbi&Viterbi frequency offset estimation algorithm is used to calculate the sum of the frequency offset of the first optical signal and the frequency f _i of the first subcarrier signal, and calculate the first The _sum of the frequency offset fq of the two-way optical signal and the frequency fq of the second-channel subcarrier signal according to +ίία f _q +f _q , the frequency interval f _q -f _i between the first subcarrier signal and the second subcarrier signal And calculating a predetermined frequency interval between the first optical signal and the second optical signal to calculate an actual frequency interval of the first optical signal and the second optical signal; or, according to + ₀₁ , f _q +f _q , The frequency interval between one subcarrier signal and the second subcarrier signal calculates an offset between the actual frequency interval of the first optical signal and the second optical signal and the predetermined frequency interval.

In practical applications, the frequency of the multi-carrier signal may also be offset. For example, the Viterbi&Viterbi frequency offset estimation algorithm calculates +ί^+ΧΙ , fq+f _L o _q +X2, where XI, X2 The offset of the frequency of the subcarrier signal. Since the multicarrier is generated by a single light source, the offset of the frequency of each subcarrier signal is equal, that is, XI and X2 are equal, and then calculated. The actual frequency interval between the first optical signal and the second optical signal, or the offset between the actual frequency interval of the first optical signal and the second optical signal and the predetermined frequency interval is accurate.

In the embodiment of the present invention, the processing device 5 has various forms, for example, a processor, an FPGA (Field-Programmable Gate Array), and a CPU (Central Processing Unit). And ASIC (Application Specific Integrated Circuit, Any one of the ASICs.

The Viterbi & Viterbi frequency offset estimation algorithm is a technique well known to those skilled in the art, and the detailed calculation method of the algorithm can be referred to "Frequency Estimation in Intradyne Reception" in the "IEEE PHOTONICS TECHNOLOGY LETTERSt" Journal on March 15, 2007, Volume 6, Issue 6. " , will not be detailed here.

In practical applications, when it is determined that the calculated frequency interval is smaller than a predetermined frequency interval of the optical signal, in order to avoid interference between the optical signals emitted by the laser array 3, the frequency interval between the optical signals is adjusted, and therefore, processing The device 5 is further configured to: when the actual frequency interval is different from the predetermined frequency interval, issue an interval adjustment command for correcting the frequency interval deviation according to the actual frequency interval and the predetermined frequency interval, or, when the offset is not equal to zero, The shift amount issues an interval adjustment command for correcting the frequency interval deviation;

The optical signal processing apparatus 100 further includes a frequency interval adjusting device 6 for tuning the transmission frequency of the first laser and/or the second laser according to the interval adjustment command, the first laser being the first optical signal in the laser array 3 The laser, the second laser is a laser that emits a second optical signal in the laser array 3, as shown in FIG. 1F.

In the embodiment of the present invention, the frequency interval adjusting device 6 adjusts the frequency interval of the first optical signal and the second optical signal. For example, the heating tuning mode may be used, or the electrical injection tuning may be used. , or using piezoelectric tuning, that is, the frequency interval adjusting device 6 is specifically used to:

加热 controlling the interval between the first optical signal and the second optical signal emitted by the laser array by means of heating tuning; or

釆 controlling the interval between the first optical signal and the second optical signal emitted by the laser array by means of electrical injection tuning; or

压电 The interval between the first optical signal and the second optical signal emitted by the laser array is controlled by piezoelectric tuning.

The above description is that the processing device 5 adjusts the frequency of the optical signal emitted by all the lasers in the laser array 3 by the frequency interval adjusting device 6 by controlling the frequency interval adjusting device 6. In practical applications, the processing device 5 can also be connected to each of the laser arrays 3, and the frequency of the optical signals emitted by each of the lasers can be adjusted by the processing device 5, as shown in Fig. 1G.

In the embodiment of the present invention, since the multi-carrier generating apparatus 1 generates a multi-carrier signal by using a single light source, the multi-carrier signal generated in this manner has an attribute with equal frequency offset, and then uses the multi-carrier signal. After any one-channel single-carrier signal is mixed with the optical signal, the frequency interval between the optical signals can be accurately calculated by mixing the multi-carrier signal with the optical signal and then using the coherent wavelength after the mixing process.

In the embodiment of the present invention, the frequency interval between the multi-carrier signals may be in various forms. Optionally, the preset frequency interval of the optical signal is an integer multiple of the frequency interval between the multi-carrier signals. For example, the frequency interval of the optical signal is 75 GHz, and the frequency interval of the multi-carrier signal can be set to 25 GHz. In this case, the first single carrier signal, the fourth single carrier signal, and the seventh single carrier signal in the multi-carrier signal are used. Coherent with the optical signal, respectively, for mixing.

Of course, in practical applications, the frequency interval between the multi-carrier signals may also be half of the predetermined frequency interval between the two optical signals. For example, the frequency interval between the multi-carrier signals is 25 GHz, and the reservation between the optical signals is The frequency interval is 50 GHz.

Further, in order to reduce the cost of the analog-to-digital conversion device 4, the frequency interval between the multi-carrier signals can be made the same as the predetermined frequency interval between the optical signals. In this case, the analog-to-digital conversion device 4 can use the low-bandwidth device. In this way, the cost will be reduced.

In the embodiment of the present invention, for example, calculating the frequency of the first type of digital signal includes the frequency offset of the first optical signal generated by the laser i and the frequency ίία of the first subcarrier signal, and the frequency of the first subcarrier signal. The offset f _x , that is, fi+fL + fx; and calculating the frequency of the second type of digital signal includes the frequency offset f _q of the second optical signal generated by the laser _q , and the frequency of the second subcarrier signal Fq , and the frequency offset f _{y of the} first subcarrier signal, that is, the coherence wavelength is fi+fLOq+ f. Since the multicarrier signal is generated by a single light source, f _X is equal to fy, then the two calculated After the frequency is subtracted, the frequency interval between the first optical signal generated by the laser i and the second optical signal generated by the laser q is obtained.

In the embodiment of the present invention, the number of optical signals emitted by the laser array 3 may be less than or equal to The number of multicarriers in a multicarrier signal may also be greater than the number of multicarriers in a multicarrier signal. Wherein, when the number of optical signals emitted by the laser array 3 is smaller than the number of multi-carriers in the multi-carrier signal, the frequency interval detection and adjustment of the optical signals emitted by all the lasers can be realized by using one-scan scanning of the multi-carrier signals, as shown in FIG. 1H. It is shown that when the interval of the optical signals is less than or equal to 37.5 GHz, the mixing and photoelectric conversion device 2 can be realized by the narrow-bandwidth mixing and photoelectric conversion device 2. For example, the absolute frequency offset value of the laser array 3 varies. At 2.5 GHz, the mixing and photoelectric conversion device 2 of 5 GHz bandwidth can be used. In this case, the analog-to-digital conversion device 4 can have a sampling rate of 10 G.

Wherein, when the number of optical signals emitted by the laser array 3 is greater than or equal to the number of multi-carriers in the multi-carrier signal, the multi-carrier signal can be multi-scanned to realize the frequency interval detection and adjustment of the optical signals emitted by all the lasers, such as As shown in FIG. II, optionally, the multi-carrier generating apparatus 1 is disposed in the middle of two lasers that emit optical signals of frequency intervals to be measured, and in this case, if a mixer is used, high-bandwidth mixing is used. The high-bandwidth mixing and photoelectric conversion device 2 and the high-amplitude analog-to-digital conversion device 4 perform processing of optical signals. At this time, the bandwidth of the mixing and photoelectric conversion device 2 is determined by the frequency interval of the multicarrier signal and the absolute frequency offset value of the two lasers that emit the frequency interval of the optical signal to be measured.

In the embodiment of the present invention, since the frequency interval between the optical signals can be accurately determined, the frequency interval between any two optical signals can be fixed, that is, the frequency interval between any two optical signals is kept constant. Therefore, spectral efficiency can be improved.

For example, the current commercial laser has a frequency offset of ±2.5 GHz, and the optical signal has a spectral width of 32 GHz. The protection frequency interval between optical signals is greater than 5 GHz to ensure no crosstalk between optical signals. Therefore, between optical signals The frequency interval should be greater than or equal to 37 GHz. In the Flexgrid system, optical signals can be transmitted at 37.5 GHz intervals to avoid optical signals. Crosstalk. After using this patent, since the frequency interval between the optical signals is a constant value, that is, the frequency interval between the optical signals can be used at 32 GHz; for example, transmitting 5 optical signals, if the light is transmitted at 37.5 GHz intervals When the signal is used, the spectrum of the 5 channels of the optical signal is 187.5 GHz. When the optical signal is processed by the solution provided by the embodiment of the present invention, the optical signal can be transmitted at a spacing of 32 GHz. At this time, the spectrum width is 140 GHz. Increased spectral efficiency. As shown in FIG. 2, an embodiment of the present invention provides a method for processing an optical signal, and the method is as follows:

Step 200: Generate a multi-carrier signal based on a single light source;

Step 210: Mixing the first optical signal transmitted by the received laser array by using the first subcarrier signal in the multicarrier signal, and transmitting the received laser array by using the second subcarrier signal in the multicarrier signal. The second optical signal is mixed;

Step 220: Convert the mixed first optical signal and the mixed second optical signal into a first electrical signal and a second electrical signal by photoelectric conversion, respectively;

Step 230: Convert the first electrical signal and the second electrical signal into a first digital signal and a second digital signal respectively by analog-to-digital conversion;

Step 240: According to a frequency interval between the first digital signal, the second digital signal, the first subcarrier signal and the second subcarrier signal, and a predetermined frequency between the first optical signal and the second optical signal Interval, calculating an actual frequency interval between the first optical signal and the second optical signal; or, according to the first digital signal, the second digital signal, and the frequency between the first subcarrier signal and the second subcarrier signal The interval calculates an offset between the actual frequency interval of the first optical signal and the second optical signal and the predetermined frequency interval.

In the embodiment of the present invention, there are multiple ways to generate a multi-carrier signal based on a single light source. Alternatively, the following methods may be used:

In the embodiment of the present invention, there are various methods for generating a multi-carrier signal by using a frequency offset locking method. Alternatively, the following methods may be used:

Multi-carrier signals are generated based on a single source and cascaded phase or amplitude modulators; or multi-carrier signals are generated based on mode-locked fiber lasers and nonlinear media.

In the embodiment of the present invention, according to the frequency interval between the first digital signal, the second digital signal, the first subcarrier signal and the second subcarrier signal, and between the first optical signal and the second optical signal a predetermined frequency interval, calculating an actual frequency interval of the first optical signal and the second optical signal; or, according to the first digital signal, the second digital signal, and the first subcarrier signal There are various ways of calculating the offset between the actual frequency interval of the first optical signal and the second optical signal and the predetermined frequency interval, and optionally, the frequency interval between the second channel and the second carrier signal. Use the following method:

According to the first digital signal and the second digital signal, the Viterbi&Viterbi frequency offset estimation algorithm is used to calculate the sum of the frequency offset of the first optical signal and the frequency f _i of the first subcarrier signal, and calculate the first The _sum of the frequency offset fq of the two-way optical signal and the frequency fq of the first sub-carrier signal is according to +ίία f _q +f _q , the frequency interval f _q -f _i between the first sub-carrier signal and the second sub-carrier signal And calculating a predetermined frequency interval between the first optical signal and the second optical signal, and calculating an actual frequency interval of the first optical signal and the second optical signal; or, according to + ₀₁ , f _q +f _LOq , The frequency interval between one subcarrier signal and the second subcarrier signal calculates an offset between the actual frequency interval of the first optical signal and the second optical signal and the predetermined frequency interval.

Further, in order to avoid interference between the optical signals, the embodiment of the present invention further includes the following operations:

When the actual frequency interval is different from the predetermined frequency interval, the transmission frequency of the first laser and/or the second laser is tuned to correct the frequency interval deviation according to the actual frequency interval and the predetermined frequency interval; or, when the offset is not equal to zero, according to Offset, tuning the transmit frequency of the first laser and/or the second laser to correct the frequency spacing deviation;

The first laser is a laser that emits a first optical signal in the laser array, and the second laser is a laser that emits a second optical signal in the laser array.

In the embodiment of the present invention, there are various ways for adjusting the frequency interval of the first optical signal and the second optical signal. Alternatively, the following manner may be used:

控 controlling the frequency interval of the first optical signal and the second optical signal by means of heating tuning; or

釆 controlling the frequency interval of the first optical signal and the second optical signal by means of electrical injection tuning; or

进行 Control the frequency interval between the first optical signal and the second optical signal by means of piezoelectric tuning System.

In the embodiment of the present invention, optionally, the interval between the optical signals emitted by the laser array 3 is an integer multiple of the interval between the multi-carrier signals.

For a better understanding of the embodiments of the present invention, a specific application scenario is given below, and a further detailed description is made for the processing procedure of the added optical signal, as shown in FIG. 3:

Step 300: 10 lasers in the laser array 3 respectively emit one optical signal; in this step, the frequency intervals of the optical signals emitted by each two adjacent lasers are equal, and the frequency interval at this time is a preset frequency interval. Because the frequency of the optical signal will drift during transmission, the frequency interval in the actual process is not the preset frequency interval, and measurement is to be performed.

Step 310: The multi-carrier generating apparatus 1 generates a multi-carrier signal including 15 sub-carriers based on a single-source frequency offset locking manner;

In this step, in order to reduce the cost of the mixer, the frequency interval between the multicarrier signals is equal to the frequency interval of the optical signals emitted from the laser array 3.

Step 320: The mixer mixes the multi-carrier signal and each of the optical signals, so that each optical signal interferes with the multi-carrier signal;

Step 330: The mixing and photodiode and analog-to-digital conversion device 4 converts the coherent optical signal into an electrical signal, and the processing device 5 calculates a frequency after mixing each optical signal and the multi-carrier signal by using a frequency offset estimation algorithm;

In this step, each frequency after mixing includes two parts, one part is the frequency after the optical signal drifts, and the other part is the frequency of the multi-carrier signal, such as: Calculating the first optical signal and multi-carrier signal generated by the laser i When the frequency is mixed, the frequency includes the frequency offset of the first optical signal generated by the laser i and the frequency ίί of the multi-carrier signal, that is, the coherence wavelength is +ίί.

Step 340: The processing device 5 calculates a frequency interval for any two optical signals, and uses a difference between the corresponding mixed frequencies as a frequency interval of any two of the optical signals.

Step 350: The frequency interval adjusting device 6 determines the transmission frequency of the laser transmitting the two optical signals to correct the frequency interval deviation when determining that the frequency interval of any two optical signals is less than the predetermined frequency interval.

In this embodiment, since the multi-carrier generating apparatus 1 uses a single light source to generate a multi-carrier signal, Therefore, the frequency offset generated by each subcarrier signal in the multicarrier signal is equal. Therefore, the difference between the frequencies of any two mixed optical signals, that is, the arbitrary two optical signals are not passed. The difference in frequency at the time of mixing, that is, the frequency interval of the optical signal, further improves the accuracy of the calculated frequency interval.

In summary, in the embodiment of the present invention, a method and an apparatus for processing an optical signal are provided. In this solution, since the multi-carrier generating apparatus generates a multi-carrier signal based on a single light source, the frequency of the first sub-carrier signal The offset between the offset and the frequency of the second subcarrier signal is equal, and the frequency interval between the first subcarrier signal and the second subcarrier signal is known, and therefore, the calculated first path The actual frequency interval between the optical signal and the second optical signal; or, the calculated offset between the actual frequency interval of the first optical signal and the second optical signal and the predetermined frequency interval, thus solving the present The accuracy of the optical signal processing process is low, and the performance of the optical communication system is affected.

The present invention has been described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each flow and/or block of the flowchart and/or block diagrams, and combinations of processes and/or blocks in the flowcharts and/or block diagrams can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing device to produce a machine for the execution of instructions for execution by a processor of a computer or other programmable data processing device. Means for implementing the functions in one or more of the flow or in a block or blocks of the flowchart.

The computer program instructions can also be stored in a computer readable memory that can direct a computer or other programmable data processing device to operate in a particular manner, such that the instructions stored in the computer readable memory produce an article of manufacture comprising the instruction device. The apparatus functions in one or more blocks of a flow or a flow diagram and/or block diagram of a flowchart.

These computer program instructions can also be loaded onto a computer or other programmable data processing device such that a series of operational steps are performed on a computer or other programmable device to produce computer-implemented processing for execution on a computer or other programmable device. Instructions are provided for implementation in the flowchart The steps of a process or a plurality of processes and/or block diagrams of functions in a block or blocks. Although the preferred embodiment of the invention has been described, it will be apparent to those skilled in the art that, Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and the modifications and The spirit and scope of the embodiments of the present invention are departed. Thus, it is intended that the present invention cover the modifications and modifications of the embodiments of the invention.

Claims

Rights request

A device for processing an optical signal, comprising:

Processing means, configured to: according to the first digital signal, the second digital signal, a frequency interval between the first subcarrier signal and the second subcarrier signal, and the first optical signal and Determining, by a predetermined frequency interval between the second optical signals, an actual frequency interval of the first optical signal and the second optical signal; or, according to the first digital signal, the second a digital signal, and a frequency interval between the first subcarrier signal and the second subcarrier signal, and calculating an actual frequency interval between the first optical signal and the second optical signal and a predetermined frequency interval The offset.

2. The apparatus according to claim 1, wherein the multi-carrier generating apparatus is specifically configured to:

3. The apparatus according to claim 2, wherein the multi-carrier generating apparatus is specifically configured to:

4. The apparatus according to any one of claims 1 to 3, wherein the mixing and photoelectric conversion device is a photodiode; or the mixing and photoelectric conversion device comprises a mixer and a photodiode Tube.

The device according to any one of claims 1 to 4, wherein the processing device is specifically configured to:

The apparatus according to any one of claims 1 to 5, wherein the processing device is any one of a processor, a field programmable gate array FPGA, a central processing unit CPU, and an application specific integrated circuit ASIC. .

7. Apparatus according to any one of claims 1 to 6 wherein:

The processing device is further configured to: when the actual frequency interval is different from the predetermined frequency interval, issue an interval adjustment command for correcting the frequency interval deviation according to the actual frequency interval and the predetermined frequency interval, or When the offset is not equal to zero, an interval adjustment command for correcting the frequency interval deviation is issued according to the offset;

8. The apparatus according to any one of claims 1 to 7, wherein the laser array is The frequency spacing between the transmitted optical signals is an integer multiple of the frequency spacing between the multicarrier signals generated by the multicarrier generating device.

9. A method of processing an optical signal, comprising:

Generating a multi-carrier signal based on a single light source;

And a frequency interval between the first digital signal, the second digital signal, the first subcarrier signal and the second subcarrier signal, and the first optical signal and the second path Calculating an actual frequency interval between the first optical signal and the second optical signal by a predetermined frequency interval between the optical signals; or, according to the first digital signal, the second digital signal, and Calculating an offset between an actual frequency interval of the first optical signal and the second optical signal and a predetermined frequency interval by a frequency interval between the first subcarrier signal and the second subcarrier signal the amount.

The method according to claim 9, wherein the generating a multi-carrier signal based on a single light source comprises:

The method of claim 10, wherein the using the frequency offset locking method to generate a multi-carrier signal comprises:

The method according to any one of claims 9 to 11, wherein said according to said a digital signal, the second digital signal, a frequency interval between the first subcarrier signal and the second subcarrier signal, and between the first optical signal and the second optical signal Determining, by a predetermined frequency interval, an actual frequency interval of the first optical signal and the second optical signal; or, according to the first digital signal, the second digital signal, and the first path And calculating, by the frequency interval between the carrier signal and the second subcarrier signal, an offset between an actual frequency interval of the first optical signal and the second optical signal and a predetermined frequency interval, specifically:

According to the + _01, the f _q + fL _0q, frequency f q-fL _0l interval between the first sub-carrier signal and the second sub-carrier signal, and the first optical path and the signal Calculating an actual frequency interval between the first optical signal and the second optical signal, or according to the + ₀₁ , the f _q +fL _0q , Calculating an actual frequency interval between the first path optical signal and the second path optical signal and a predetermined frequency interval by using a frequency interval _fq- f _i between the first path subcarrier signal and the second path subcarrier signal The offset between.

The method according to any one of claims 9 to 12, wherein the method further comprises: when the actual frequency interval is different from the predetermined frequency interval, according to the actual frequency interval and the Tuning a frequency interval of the first laser and/or the second laser to correct a frequency interval deviation;

14. The method of any of claims 9-13, wherein the laser array The frequency spacing between the transmitted optical signals is an integer multiple of the frequency spacing between the multi-carrier signals.