CN111900932A - Frequency discrimination method and system based on optical fiber delay line - Google Patents
Frequency discrimination method and system based on optical fiber delay line Download PDFInfo
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- CN111900932A CN111900932A CN202010504912.8A CN202010504912A CN111900932A CN 111900932 A CN111900932 A CN 111900932A CN 202010504912 A CN202010504912 A CN 202010504912A CN 111900932 A CN111900932 A CN 111900932A
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Abstract
The invention discloses a frequency discrimination method and a frequency discrimination system based on an optical fiber delay line, relates to the technical field of frequency measurement, and aims to solve the problems that in the prior laser technology, the output power of a laser with good intensity noise index cannot meet the system requirement, and the sensitivity index of a delay line frequency discriminator is reduced. The method comprises the following steps: the method comprises the steps of performing photoelectric conversion and photoelectric modulation on a first optical signal under the driving of an input electric signal to generate an output electric signal, delaying the output electric signal, and demodulating the delayed output electric signal to obtain a first electric signal; delaying the second optical signal, performing photoelectric conversion and photoelectric modulation on the delayed second optical signal under the action of the input electric signal to obtain a delayed photoelectric signal, demodulating the delayed photoelectric signal to obtain a second electric signal, performing phase detection on the first electric signal and the second electric signal, and outputting a frequency discrimination signal. The frequency discrimination method and the frequency discrimination system improve the output power of the laser and the sensitivity index of the delay line frequency discriminator.
Description
Technical Field
The invention relates to the technical field of frequency measurement, in particular to a frequency discrimination method and a frequency discrimination system based on an optical fiber delay line.
Background
The frequency discriminator is used for corresponding the output signal voltage with the input signal frequency, is widely used for signal demodulation in frequency shift keying and phase shift keying coding of a high-speed communication system and is used for generating an error signal in an automatic frequency control loop, and is also widely applied in the fields of optical microwave signal generation technology and high-frequency signal delay. The frequency discrimination delay line method based on the heterodyne technology is a widely used frequency measurement method, utilizes the low-loss transmission characteristic of optical fibers, overcomes the problem of long delay distance loss, and has wide application. However, since the conventional frequency discrimination fiber delay line has a certain requirement on the noise of the light source in the system, the indexes of the relative intensity noise of the light source, the frequency noise of the light source, the output power of the light source and the like need to be considered in a compromise manner when the light source is selected so as to meet the design requirement. In the existing laser technology, the output power of the laser with good intensity noise index often cannot meet the system requirement, and the sensitivity index of the delay line frequency discriminator is reduced.
Disclosure of Invention
The invention aims to provide a frequency discrimination method based on an optical fiber delay line, which is used for improving the output power of a laser and improving the sensitivity of a frequency discriminator in Yanchi county.
In order to achieve the above purpose, the invention provides the following technical scheme:
a frequency discrimination method based on an optical fiber delay line is provided, which comprises the following steps:
the method comprises the steps of carrying out photoelectric conversion and photoelectric modulation on a first optical signal under the drive of an input electric signal to generate an output electric signal, delaying the output electric signal, and demodulating the delayed output electric signal to obtain a first electric signal;
delaying the second optical signal, performing photoelectric conversion and photoelectric modulation on the delayed second optical signal under the action of an input electric signal to obtain a delayed photoelectric signal, and demodulating the delayed photoelectric signal to obtain a second electric signal;
and carrying out phase detection on the first electric signal and the second electric signal, and outputting a frequency discrimination signal.
Compared with the prior art, the frequency discrimination method based on the optical fiber delay line provided by the invention has the advantages that the optical modulation, the time delay and the phase detection are respectively carried out on the input electric signal in the two channels, and the two channels adopt the same optical fiber delay line and the dual-port electro-optic modulator, so that the system additional noise introduced by the output signal of the frequency discriminator is greatly reduced; the performance of the delay line frequency discriminator does not depend on the influence of the intensity noise index of the light source any more, so that the cost performance of the frequency discriminator is greatly improved; the frequency discrimination delay line can be used for the design of the frequency discrimination delay line in a microwave millimeter wave phase noise detection system without a reference source, the signal-to-noise ratio of the system is not limited by the index of a light source, and the sensitivity of the phase detection system is improved.
The invention also provides a frequency discrimination system based on the optical fiber delay line, which comprises an electro-optical modulator, a light delay line, a first photoelectric detector, a second light detector and a phase detector;
the photoelectric modulator is used for performing photoelectric conversion and photoelectric modulation on the first optical signal under the drive of an input electric signal to generate an output optical electric signal;
the optical fiber delay line is used for delaying the photoelectric signal and the second optical signal, transmitting the delayed output photoelectric signal to the second photoelectric detector, and transmitting the delayed second optical signal to the photoelectric modulator;
the photoelectric modulator is also used for performing photoelectric conversion and photoelectric modulation on the delayed second optical signal under the drive of the input electric signal to generate a delayed photoelectric signal;
the first photoelectric detector is used for demodulating the delayed photoelectric signal to obtain a second electric signal;
the second photoelectric detector is used for demodulating the delayed output photoelectric signal to obtain a first electric signal;
and the phase detector is used for carrying out phase detection on the first electric signal and the second electric signal and outputting a frequency discrimination signal.
Compared with the prior art, the beneficial effects of the frequency discrimination system based on the optical fiber delay line provided by the invention are the same as the beneficial effects of the frequency discrimination method based on the optical fiber delay line in the technical scheme, and the details are not repeated here.
Drawings
The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the invention and not to limit the invention. In the drawings:
FIG. 1 is a schematic flow chart of a method for frequency discrimination based on an optical fiber delay line according to an embodiment of the present invention;
figure 2 is a schematic block diagram of a fiber delay line based frequency discrimination system in an embodiment of the present invention.
Detailed Description
In order to make the technical problems, technical solutions and advantageous effects to be solved by the present invention more clearly apparent, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.
It will be understood that when an element is referred to as being "secured to" or "disposed on" another element, it can be directly on the other element or be indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or be indirectly connected to the other element.
Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the present invention, "a plurality" means two or more unless specifically defined otherwise. The meaning of "a number" is one or more unless specifically limited otherwise.
In the description of the present invention, it is to be understood that the terms "upper", "lower", "front", "rear", "left", "right", and the like indicate orientations or positional relationships based on those shown in the drawings, and are only for convenience of description and simplicity of description, but do not indicate or imply that the referred device or element must have a specific orientation, be constructed in a specific orientation, and be operated, and thus, should not be construed as limiting the present invention.
In the description of the present invention, it should be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; can be mechanically or electrically connected; either directly or indirectly through intervening media, either internally or in any other relationship. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.
The heterodyne technology based frequency discrimination delay line method is a widely used frequency measurement method, wherein a traditional frequency discrimination delay line is based on an electrical transmission system, and when the frequency discrimination response frequency is small, the frequency discrimination delay length of the delay line is required to be long, so that the power consumption of the frequency discrimination system is overhigh, and the signal-to-noise ratio of the system is extremely poor. The problem of long delay distance loss is solved by using the low-loss transmission characteristic of the optical fiber, and the frequency discrimination device based on the optical fiber delay line is widely applied. However, since the conventional frequency discrimination fiber delay line has a certain requirement on the noise of the light source in the system, the indexes of the relative intensity noise of the light source, the frequency noise of the light source, the output power of the light source and the like need to be considered in a compromise manner when the light source is selected so as to meet the design requirement. The relative intensity noise degrades the signal-to-noise ratio of the delay line and affects the performance of the delay line frequency discrimination system. In the existing laser technology, the output power of the laser with good intensity noise index often cannot meet the system requirement, and the sensitivity index of the delay line frequency discriminator is reduced.
Referring to fig. 1 in detail, an embodiment of the present invention provides a frequency discrimination method based on an optical fiber delay line, including:
step S10, performing photoelectric conversion and photoelectric modulation on the first optical signal under the drive of the input electrical signal to generate an output optical electrical signal, delaying the output optical electrical signal, and demodulating the delayed output optical electrical signal to obtain a first electrical signal;
step S20, delaying the second optical signal, performing photoelectric conversion and photoelectric modulation on the delayed second optical signal under the action of the input electrical signal to obtain a delayed photoelectric signal, and demodulating the delayed photoelectric signal to obtain a second electrical signal;
in step S30, the first electrical signal and the second electrical signal are phase-detected, and a frequency discrimination signal is output.
In the specific implementation:
the frequency discrimination method based on the optical fiber delay line is divided into 2 channels, in the first channel, a first optical signal is subjected to photoelectric conversion and photoelectric modulation under the drive of an input electric signal to generate an output optical electric signal, the output optical electric signal is subjected to time delay operation to obtain a delayed output optical electric signal, the delayed output optical electric signal is output, and the delayed output optical electric signal is demodulated to obtain the first electric signal;
in the second channel, the second optical signal is delayed, the delayed second optical signal is subjected to photoelectric conversion and photoelectric modulation under the action of an input electric signal to obtain a delayed photoelectric signal, and the delayed photoelectric signal is demodulated to obtain a second electric signal;
and finally, carrying out phase detection on the first electric signal and the second electric signal and outputting a frequency discrimination signal.
Compared with the prior art, the frequency discrimination method based on the optical fiber delay line provided by the invention has the advantages that the optical modulation, the time delay and the phase detection are respectively carried out on the input electric signal in the two channels, and the two channels adopt the same optical fiber delay line and the dual-port electro-optic modulator, so that the system additional noise introduced by the output signal of the frequency discriminator is greatly reduced; the performance of the delay line frequency discriminator does not depend on the influence of the intensity noise index of the light source any more, so that the cost performance of the frequency discriminator is greatly improved; the frequency discrimination delay line can be used for the design of the frequency discrimination delay line in a microwave millimeter wave phase noise detection system without a reference source, the signal-to-noise ratio of the system is not limited by the index of a light source, and the sensitivity of the phase detection system is improved.
As an implementation manner, before performing photoelectric conversion and photoelectric modulation on a first optical signal under driving of an input electrical signal to generate an output optical electrical signal, delaying the output optical electrical signal, and demodulating the delayed output optical electrical signal to obtain a first electrical signal, the method further includes:
and generating an optical signal, splitting the optical signal to obtain a first optical signal and a second optical signal.
Through splitting the generated optical signals, the first optical signals and the second optical signals in the same form can be transmitted to the first channel and the second channel for optical signal processing operation, and the uniformity of the output optical signals is also ensured.
As an implementation manner, before performing photoelectric conversion and photoelectric modulation on a first optical signal under driving of an input electrical signal, and before generating an output optical electrical signal, delaying the output optical electrical signal, and demodulating the delayed output optical electrical signal to obtain a first electrical signal, the method further includes:
and carrying out reverse isolation and directional output on the delayed output photoelectric signal.
The unidirectional single-channel transmission of the output photoelectric signals is ensured, the interference to other channel signals in the transmission process of the output photoelectric signals is avoided, and the accuracy of the final result is ensured.
As an implementable manner, before delaying the second optical signal, and after performing photoelectric conversion and photoelectric modulation on the delayed optical signal under the action of the input electrical signal to obtain a delayed photoelectric signal, demodulating the delayed photoelectric signal to obtain a second electrical signal, the method further comprises;
and carrying out reverse isolation and directional output on the delayed photoelectric signal.
The unidirectional single-channel transmission of the delayed photoelectric signal is ensured, the interference to other channel signals in the transmission process of the delayed photoelectric signal is avoided, and the accuracy of the final result is ensured.
As an implementation, the phase detection of the first electrical signal and the second electrical signal includes:
and performing phase difference operation on the first electric signal and the second electric signal.
The phase difference between the first electric signal and the second point signal can be accurately determined by performing phase difference operation on the first electric signal and the second electric signal, and the frequency discrimination signal can be output according to the phase difference.
With particular reference to fig. 2, an embodiment of the present invention further provides a frequency discrimination system based on an optical fiber delay line, which includes an electro-optical modulator 105, a light delay line 106, a first photodetector 107, a second photodetector 108, and a phase detector 109;
the photoelectric modulator 105 is configured to perform photoelectric conversion and photoelectric modulation on the first optical signal under the driving of the input electrical signal, and generate an output optical electrical signal;
the optical fiber delay line 106 is configured to delay the output optical electrical signal and the second optical signal, transmit the delayed output optical electrical signal to the second photodetector 108, and transmit the delayed second optical signal to the photoelectric modulator 105;
the photoelectric modulator 105 is further configured to perform photoelectric conversion and photoelectric modulation on the delayed second optical signal under the driving of the input electrical signal, so as to generate a delayed photoelectric signal;
the first photodetector 107 is configured to demodulate the delayed photoelectric signal to obtain a second electrical signal;
the second photodetector 108 is configured to demodulate the delayed output photoelectric signal to obtain a first electric signal;
and a phase detector 109 for detecting the phase of the first electrical signal and the second electrical signal and outputting a frequency discrimination signal.
As an implementation, the frequency discrimination system further includes a laser 101 and an optical beam splitter 102;
a laser 101 for emitting a laser signal;
the optical splitter 102 is configured to split the laser signal into a first optical signal and a second optical signal.
Through splitting the generated optical signals, the first optical signals and the second optical signals in the same form can be transmitted to the first channel and the second channel for optical signal processing operation, and the uniformity of the output optical signals is also ensured.
As an implementation, the frequency discrimination system further includes a first optical circulator 103;
the first optical circulator 103 is configured to perform reverse isolation on the first optical signal and the delayed optoelectronic signal, and directionally output the first optical signal to the optoelectronic modulator 105;
the delayed photo-electric signal is directionally output to the first photo-detector 107.
The unidirectional single-channel transmission of the output photoelectric signals is ensured, the interference to other channel signals in the transmission process of the output photoelectric signals is avoided, and the accuracy of the final result is ensured.
As an implementation, the frequency discrimination system further includes a second optical circulator 104;
the second optical circulator 104 is configured to perform reverse isolation on the second optical signal and the delayed output optical electrical signal, and directionally output the second optical signal to the optical fiber delay line 106;
the delayed output optical electrical signal is directed to the second photodetector 108.
The unidirectional single-channel transmission of the delayed photoelectric signal is ensured, the interference to other channel signals in the transmission process of the delayed photoelectric signal is avoided, and the accuracy of the final result is ensured.
As an implementation, the phase detector is further configured to perform a phase difference operation on the first electrical signal and the second electrical signal.
The phase difference between the first electric signal and the second point signal can be accurately determined by performing phase difference operation on the first electric signal and the second electric signal, and the frequency discrimination signal can be output according to the phase difference.
The output light of the laser 101 is divided into two paths of signal transmission, namely an a path and a b path, after passing through the optical beam splitter 102, wherein the signal transmission direction of the a path is represented by thin lines, and the signal transmission direction of the b path is represented by thick lines;
after being isolated and directionally transmitted and controlled by the first optical circulator 103, the a-path signal output by the optical beam splitter 102 is transmitted to an electro-optical modulator 105 with reciprocity, the electro-optical modulator 105 performs photoelectric conversion and electro-optical modulation under the drive of an input electric signal Vin, and inputs the optical signal loaded with the electric signal into an optical fiber delay line 106; the optical fiber delay line 106 delays the optical signal modulated by the electro-optical modulator 105, the output signal of the optical fiber delay line 106 is the modulated optical signal loaded with the electrical input signal information and delayed, and the modulated delayed signal output by the optical fiber delay line 106 is output to the second photodetector 108 through the reverse isolation and directional transmission characteristics of the second optical circulator 104; the second photodetector 108 converts the a-channel input modulated optical signal into an electrical signal, demodulates the delayed a-channel electrical signal, and inputs the demodulated a-channel electrical delayed signal into the phase detector 109 for phase detection;
after b-path signals output by the optical beam splitter 102 are isolated and directionally transmitted and controlled by the second optical circulator 104, the b-path signals are delayed by an optical fiber delay line 106, then input into an electro-optical modulator 105, the electro-optical modulator 105 performs photoelectric conversion and signal modulation under the driving of an input electric signal Vin, and the optical modulation signals are output to a first photoelectric detector 107 through the reverse isolation and directional transmission characteristics of the first optical circulator 103; the first photodetector 107 converts the b-channel input optical modulation signal into an electrical signal, demodulates the b-channel electrical signal, and inputs the demodulated b-channel electrical signal into the phase detector 109 for phase detection. Because the b-path signal passes through the delay line before electro-optical conversion and modulation, the b-path signal only has a delay effect on the optical signal, and has no delay effect on the electrical signal transmitted by the b-path.
The electrical signal demodulated and output by the photodetector is subjected to phase detection by the phase detector 109, and a frequency discrimination signal is output.
In the foregoing description of embodiments, the particular features, structures, materials, or characteristics may be combined in any suitable manner in any one or more embodiments or examples.
The above description is only for the specific embodiments of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art can easily conceive of the changes or substitutions within the technical scope of the present invention, and all the changes or substitutions should be covered within the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the appended claims.
Claims (10)
1. A method for frequency discrimination based on a fiber delay line, comprising:
the method comprises the steps of carrying out photoelectric conversion and photoelectric modulation on a first optical signal under the drive of an input electric signal to generate an output electric signal, delaying the output electric signal, and demodulating the delayed output electric signal to obtain a first electric signal;
delaying a second optical signal, performing photoelectric conversion and photoelectric modulation on the delayed second optical signal under the action of an input electric signal to obtain a delayed photoelectric signal, and demodulating the delayed photoelectric signal to obtain a second electric signal;
and carrying out phase detection on the first electric signal and the second electric signal, and outputting a frequency discrimination signal.
2. The method of claim 1, wherein before performing the optical-to-electrical conversion and the optical-to-electrical modulation on the first optical signal under the driving of the input electrical signal to generate the output electrical signal, delaying the output electrical signal, and demodulating the delayed output electrical signal to obtain the first electrical signal, the method further comprises:
and generating an optical signal, splitting the optical signal to obtain the first optical signal and the second optical signal.
3. The method of claim 1, wherein before performing the optical-to-electrical conversion and the optical-to-electrical modulation on the first optical signal under driving of the input electrical signal and generating the output optical electrical signal, after delaying the output optical electrical signal and before demodulating the delayed output optical electrical signal to obtain the first electrical signal, the method further comprises:
and carrying out reverse isolation and directional output on the delayed output photoelectric signal.
4. The method of claim 1, wherein before the delaying the second optical signal, and after the performing the optical-to-electrical conversion and the optical-to-electrical modulation on the delayed optical signal under the action of the input electrical signal to obtain the delayed optical-to-electrical signal, the demodulating the delayed optical-to-electrical signal to obtain the second electrical signal, further comprises;
and carrying out reverse isolation and directional output on the delayed photoelectric signal.
5. The method of claim 1, wherein the phase detecting the first electrical signal and the second electrical signal comprises:
and performing phase difference operation on the first electric signal and the second electric signal.
6. A frequency discrimination system based on an optical fiber delay line is characterized by comprising an electro-optical modulator, an optical fiber delay line, a first photoelectric detector, a second photoelectric detector and a phase detector;
the photoelectric modulator is used for performing photoelectric conversion and photoelectric modulation on the first optical signal under the drive of an input electric signal to generate an output optical electric signal;
the optical fiber delay line is used for delaying the output optical electrical signal and the second optical signal, transmitting the delayed output optical electrical signal to the second photoelectric detector, and transmitting the delayed second optical signal to the photoelectric modulator;
the photoelectric modulator is also used for performing photoelectric conversion and photoelectric modulation on the delayed second optical signal under the drive of the input electric signal to generate a delayed photoelectric signal;
the first photoelectric detector is used for demodulating the delayed photoelectric signal to obtain a second electric signal;
the second photoelectric detector is used for demodulating the delayed output photoelectric signal to obtain a first electric signal;
and the phase detector is used for carrying out phase detection on the first electric signal and the second electric signal and outputting a frequency discrimination signal.
7. The fiber optic delay line based frequency discrimination system of claim 6, wherein the frequency discrimination system further comprises a laser and an optical beam splitter;
the laser is used for emitting laser signals;
the optical beam splitter is configured to split a laser signal into the first optical signal and the second optical signal.
8. The fiber delay line based frequency discrimination system of claim 6 further comprising a first optical circulator;
the first optical circulator is used for carrying out reverse isolation on the first optical signal and the delayed photoelectric signal and outputting the first optical signal to the photoelectric modulator in a directional mode;
and outputting the delayed photoelectric signal to the first photoelectric detector in a directional mode.
9. The fiber delay line based frequency discrimination system of claim 6 further comprising a second optical circulator;
the second optical circulator is used for carrying out reverse isolation on the second optical signal and the delayed output optical electrical signal and directionally outputting the second optical signal to the optical fiber delay line;
and directionally transmitting the delayed output photoelectric signal to the second photoelectric detector.
10. The fiber optic delay line-based frequency discrimination system of claim 6, wherein said phase detector is configured to perform a phase difference operation on said first electrical signal and said second electrical signal.
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Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0316303A (en) * | 1989-03-30 | 1991-01-24 | Yokogawa Electric Corp | Frequency discriminator and high frequency signal generator using same |
| CN105264766A (en) * | 2013-03-12 | 2016-01-20 | 协同微波公司 | Integrated self injection locked self phase loop locked optoelectronic oscillator |
| CN107835055A (en) * | 2017-09-29 | 2018-03-23 | 北京大学 | A kind of microwave source phase noise measurement method and system |
| CN108964797A (en) * | 2018-06-15 | 2018-12-07 | 浙江大学 | A kind of microwave signal source phase noise automatic measuring system and method based on frequency-discrimination method |
-
2020
- 2020-06-05 CN CN202010504912.8A patent/CN111900932B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0316303A (en) * | 1989-03-30 | 1991-01-24 | Yokogawa Electric Corp | Frequency discriminator and high frequency signal generator using same |
| CN105264766A (en) * | 2013-03-12 | 2016-01-20 | 协同微波公司 | Integrated self injection locked self phase loop locked optoelectronic oscillator |
| CN107835055A (en) * | 2017-09-29 | 2018-03-23 | 北京大学 | A kind of microwave source phase noise measurement method and system |
| CN108964797A (en) * | 2018-06-15 | 2018-12-07 | 浙江大学 | A kind of microwave signal source phase noise automatic measuring system and method based on frequency-discrimination method |
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