CN204349204U - For control device and the optical-electronic oscillator control system of optical-electronic oscillator - Google Patents

Abstract

The utility model discloses a control device for a photoelectric oscillator and a photoelectric oscillator control system. Wherein, the control device includes: a phase shifter, connected with the injection source, for phase shifting the second signal; an acquisition unit, connected with the output terminal of the photoelectric oscillator, used for collecting the output signal of the photoelectric oscillator and coupling out The feedback signal; the mixer is connected with the phase shifter and the acquisition unit respectively, and is used for phase discrimination of the second signal after the phase shift and the feedback signal; the servo module is connected with the mixer and the photoelectric oscillator respectively , for controlling the phase of the output signal of the photoelectric oscillator to be locked on the second signal according to the phase-discriminated signal. The utility model solves the problem of low long-term stability of the photoelectric oscillator in the prior art, and achieves the effect of controlling the long-term stability of the OEO output signal.

Description

Control device for photoelectric oscillator and photoelectric oscillator control system

technical field

The utility model relates to the field of optoelectronics, in particular to a control device for an optoelectronic oscillator and a control system for the optoelectronic oscillator.

Background technique

Ultrastable oscillators are at the heart of electronic communication systems. High-quality microwave oscillators play an important role in optical communication, satellite communication, microwave communication, and high-precision measurement. Traditional microwave sources are generally obtained by multiple frequency multiplication of crystal oscillators, but as the number of frequency multiplication increases, the phase noise (short-term stability) will become larger and larger, that is to say, the phase noise will increase with the increase of the carrier frequency. And increase. The utility model of the Opto-Electronic Oscillator (OEO for short) solves this problem. The phase noise of OEO based on fiber delay does not increase with the increase of the oscillation frequency, and it is a high-quality ultra-stable microwave and millimeter wave oscillation source. optional. The basic principle is that the continuous light emitted by the laser is modulated by the intensity of the oscillating signal by the electro-optic modulator, and then transmitted to the front end of the photodetector through the optical fiber. It is fed back to the electrical input terminal of the modulator, and then the next cycle is performed, and the frequency point that satisfies the Barkhausen oscillation condition (the open-loop gain is greater than 1, and the difference is an integer multiple of 2π) finally forms a stable oscillation signal.

Under the condition that other device performance indicators remain unchanged, the phase noise of OEO is inversely proportional to the square of the fiber delay. The longer the optical fiber, the lower the phase noise, but the free spectral range will be smaller and smaller (the free spectral range corresponding to 1km SMF fiber is about 200kHz), and it is impossible to find such a high-Q narrow-band filter in the microwave frequency band. Dispersion is effectively suppressed. The injection locking method is an effective way to suppress spurs: a stable microwave signal is injected into the long fiber ring OEO, and the frequency of the injected signal is controlled so that it is consistent with the corresponding frequency of a certain mode when the long fiber ring OEO oscillates alone, which can make the long fiber ring OEO This mode signal of the optical fiber ring OEO gains an advantage in "mode competition", and then suppresses other modes, and finally realizes single-mode output.

Due to the high temperature sensitivity of the glass communication optical fiber, the delay of the optical fiber will also change with the stable change, so that the frequency of the oscillating signal will drift. Not only that, but other external disturbances will destroy its long-term stability. This results in low long-term stability of the photoelectric oscillator. At this stage, constant temperature control and shock absorption are commonly used at home and abroad to control the long-term stability of OEO. This method has a complicated structure and consumes a lot of energy; some researchers also use the method of compensating for optical fiber delay fluctuations in the optical domain. .

Aiming at the problem of low long-term stability of the optoelectronic oscillator in the prior art, no effective solution has been proposed yet.

Utility model content

The main purpose of the utility model is to provide a control device for a photoelectric oscillator and a photoelectric oscillator control system to solve the problem of low long-term stability of the photoelectric oscillator in the prior art.

In order to achieve the above purpose, according to an aspect of the embodiment of the present utility model, a control device for a photoelectric oscillator is provided. Wherein, the photoelectric oscillator is connected with the injection source, and the injection source is used to output the first signal and the second signal to the photoelectric oscillator, and the control device for the photoelectric oscillator according to the utility model includes: a phase shifter, and The injection source is connected to phase-shift the second signal; the acquisition unit is connected to the output terminal of the photoelectric oscillator and used to collect the feedback signal coupled from the output signal of the photoelectric oscillator; the mixer is connected to the phase-shift The detector and the acquisition unit are connected respectively for phase discrimination of the second signal after phase shift and the feedback signal; the servo module is connected with the mixer and the photoelectric oscillator respectively for controlling the photoelectricity according to the signal after phase discrimination The oscillator's output signal is phase locked to the second signal.

Further, the photoelectric oscillator has a built-in voltage-controlled phase shifter, the servo module is connected to the voltage-controlled phase shifter, and the servo module is used to control the phase locking of the output signal of the photoelectric oscillator by changing the voltage of the voltage-controlled phase shifter. on the second signal.

Further, the servo module is also used to amplify the phase-discriminated signal, and control the voltage fluctuation of the phase-discriminated feedback signal to just cover the phase shift range of 0-360 degrees of the voltage-controlled phase shifter.

Further, the control device also includes: a first microwave amplifier, connected between the phase shifter and the mixer, for amplifying the phase-shifted second signal; a second microwave amplifier, connected between the acquisition unit and the mixer Between the frequency converters, it is used to amplify the feedback signal.

Further, the control device further includes: a low-pass filter connected between the mixer and the servo module, and used for low-pass filtering the phase-discriminated signal.

Further, the angle at which the phase shifter shifts the phase of the second signal is 90 degrees.

In order to achieve the above purpose, according to another aspect of the embodiments of the present utility model, a photoelectric oscillator control system is provided. According to the utility model, the photoelectric oscillator control system includes: an injection source, used to output the first signal and a second signal; a photoelectric oscillator, connected with the injection source, used to receive the first signal, and obtain an output from the first signal Signal; control device, the control device is the control device provided above, connected to the injection source and the photoelectric oscillator, and used to control the phase locking of the output signal to the second signal.

Further, the photoelectric oscillator includes a first photoelectric oscillator and a second photoelectric oscillator, the output end of the first photoelectric oscillator is connected to the input end of the second photoelectric oscillator, and the control device includes a first control device and a second control device device, wherein the first control device is respectively connected to the injection source and the first photoelectric oscillator, and is used to control the phase locking of the output signal of the first photoelectric oscillator to the second signal; the first control device is connected to the first photoelectric oscillator The output terminals of the oscillator are respectively connected to the second photoelectric oscillator, and are used to control the phase locking of the output signal of the second photoelectric oscillator to the output signal of the first photoelectric oscillator.

According to the embodiment of the present invention, the signal of the injection source is divided into two parts, one part is injected into the OEO, while ensuring the low phase noise (short-term stability) of the OEO oscillating signal, its single-mode output is guaranteed, and the other part is used as a reference signal, through mixing The long-term stability of the OEO output signal is controlled by frequency detection and phase detection, thereby solving the problem of low long-term stability of the photoelectric oscillator in the prior art, and achieving the effect of controlling the long-term stability of the OEO output signal.

Description of drawings

The accompanying drawings constituting a part of this application are used to provide a further understanding of the utility model, and the schematic embodiments of the utility model and their descriptions are used to explain the utility model, and do not constitute an improper limitation of the utility model. In the attached picture:

1 is a schematic diagram of a control device for a photoelectric oscillator according to an embodiment of the present invention; and

Fig. 2 is a schematic diagram of a photoelectric oscillator control system according to an embodiment of the present invention.

Detailed ways

It should be noted that, in the case of no conflict, the embodiments in the present application and the features in the embodiments can be combined with each other. The utility model will be described in detail below with reference to the accompanying drawings and in conjunction with the embodiments.

In order to enable those skilled in the art to better understand the solution of the utility model, the technical solution in the embodiment of the utility model will be clearly and completely described below in conjunction with the accompanying drawings in the embodiment of the utility model. Obviously, the described The embodiments are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present utility model, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts shall fall within the protection scope of the present utility model.

It should be noted that the terms "first" and "second" in the specification and claims of the present utility model and the above drawings are used to distinguish similar objects, but not necessarily used to describe a specific order or sequence . It should be understood that the data so used may be interchanged under appropriate circumstances in order to facilitate the embodiments of the invention described herein. Furthermore, the terms "comprising" and "having", as well as any variations thereof, are intended to cover a non-exclusive inclusion, e.g. a system, product or device comprising a series of elements need not be limited to those elements explicitly listed, but may include other components not expressly listed or inherent to the system, product or equipment.

The embodiment of the utility model provides a control device for a photoelectric oscillator. The control device can be used in a photoelectric oscillator, which can be a photoelectric oscillator injected into a microwave source once, or a photoelectric oscillator injected into a microwave source twice.

FIG. 1 is a schematic diagram of a control device for an optoelectronic oscillator according to an embodiment of the present invention. As shown in Figure 1, the photoelectric oscillator 20 is connected with the injection source 10, and the photoelectric oscillator 20 can be a long optical fiber ring OEO, and the injection source 10 is used to output the first signal to the photoelectric oscillator 20, and output the second signal, Wherein, the signal output by the injection source 10 is divided into two parts, one part is the first signal to realize the injection locking of the long optical fiber ring OEO, and the other part is the second signal as a stable reference signal and the output signal of the OEO, that is, the output signal of the optical fiber ring Conduct phase identification.

As shown in FIG. 1 , the control device includes a phase shifter 301 , an acquisition unit (not shown in the figure), a mixer 302 and a servo module 303 . The phase shifter 301 is connected with the injection source 10 and used for phase shifting the second signal. The collection unit is connected to the output terminal of the photoelectric oscillator 20 through the port 2, and is used for collecting the feedback signal coupled from the output signal of the photoelectric oscillator 20. The mixer 302 is connected with the phase shifter 301 and the acquisition unit respectively, and is used for performing phase discrimination on the phase-shifted second signal and the feedback signal; the servo module 303 is connected with the mixer 302 and the photoelectric oscillator 20 respectively, It is used to control the phase of the output signal of the photoelectric oscillator 20 to be locked on the second signal according to the phase-discriminated signal.

Preferably, the phase shifter is used to shift the phase of the second signal by 90 degrees, so as to perform phase detection processing on it through the mixer. Then, the voltage signal after phase discrimination can be fed back to the voltage control terminal of the voltage-controlled phase shifter in the OEO loop, and the phase of the output signal can be controlled through the phase shift of the voltage-controlled phase shifter until the output signal is consistent with the reference signal, that is, the first The two signals are synchronized, and finally a stable output signal is obtained. Preferably, the main function of the servo module includes two parts, one part amplifies the weak voltage signal in the phase-discriminated signal, and the other part manages the feedback voltage in the phase-discriminated signal to ensure that its value fluctuation just covers OEO The phase shift range of the voltage-controlled phase shifter in the loop is 0-360 degrees.

According to the embodiment of the present invention, the signal of the injection source is divided into two parts, one part is injected into the OEO, while ensuring the low phase noise (short-term stability) of the OEO oscillating signal, its single-mode output is guaranteed, and the other part is used as a reference signal, through mixing The long-term stability of the OEO output signal is controlled by frequency detection and phase detection, thereby solving the problem of low long-term stability of the photoelectric oscillator in the prior art, and achieving the effect of controlling the long-term stability of the OEO output signal.

Compared with the traditional OEO stability control device, the signal processing part of the utility model is all carried out in the electrical domain, which overcomes the complexity of the optical domain control system and has higher control precision.

Preferably, the photoelectric oscillator 20 has a built-in voltage-controlled phase shifter, and the servo module 303 is connected to the voltage-controlled phase shifter, and the servo module 303 is used to control the output signal of the photoelectric oscillator by changing the voltage of the voltage-controlled phase shifter phase locked to the second signal. The servo module 303 controls the phase of the output signal by changing the voltage of the voltage-controlled phase shifter, and finally makes the phase of the output signal locked to the reference signal to achieve stable output.

Preferably, the control device further includes: a first microwave amplifier 304, connected between the phase shifter 301 and the mixer 302, for amplifying the phase-shifted second signal; a second microwave amplifier 305, connected between Between the acquisition unit and the mixer 302, used for amplifying the feedback signal.

Specifically, the first microwave amplifier is used to amplify the reference signal (second signal), and the second microwave amplifier is used to amplify the feedback signal to saturate the mixer and suppress amplitude noise of the mixer.

Preferably, the control device further includes: a low-pass filter 306, connected between the mixer 302 and the servo module 303, for low-pass filtering the phase-discriminated signal. The low-pass filter 306 is used to perform low-pass filtering on the phase-detected baseband signal to suppress high-frequency components after frequency mixing.

Specifically, the phase shifter is used to shift the phase of the reference signal, that is, the second signal by 90 degrees, to achieve the purpose of frequency mixing and phase discrimination; the microwave amplifier is used to amplify the reference signal and the feedback signal to saturate the mixer and suppress the frequency of the mixer. Amplitude noise; using a mixer to achieve 90-degree phase-shifted microwave reference source and feedback signal phase discrimination; using a low-pass filter to achieve low-pass filtering on the baseband signal after phase discrimination to suppress high-frequency components after mixing; The main function of the servo module includes two parts, one part amplifies the weak voltage signal, and the other part manages the feedback voltage to ensure that its value fluctuation just covers the phase shift range of 0-360 degrees of the voltage-controlled phase shifter in the OEO ring.

The injection source signal is divided into two parts, one part is connected to the phase shifter of the control device through port 1 to achieve a 90-degree phase shift; the other part is injected into the long optical fiber ring OEO, and injection locking is performed on one of the oscillation modes to suppress the growth of other modes. A single-mode output with low phase noise is realized, and the output signal is coupled to a part of the feedback signal, which is connected to the mixer of the stability control device through port 2. The two-way orthogonal signals are phase-detected in the mixer. After passing through the low-pass filter, the feedback signal is amplified in the servo module. After adjustment, it is connected to the voltage-controlled phase shifter in the long optical fiber ring through port 3. By changing The phase of the output signal is controlled by the voltage of the phase device, and finally the phase of the output signal is locked to the reference signal to achieve stable output.

From a structural point of view, the control device involved in the utility model can be regarded as a three-port device, port 1 is connected to the reference signal, port 2 is connected to the feedback signal, and port 3 is used as an output port to connect to the long optical fiber ring OEO built-in voltage-controlled phase shifter.

The embodiment of the utility model provides a photoelectric oscillator control system. The photoelectric oscillator control system includes: an injection source, a photoelectric oscillator and a control device.

The injection source is used to output the first signal and the second signal. The photoelectric oscillator is connected with the injection source for receiving the first signal and obtaining an output signal from the first signal. The control device is the control device provided in the above-mentioned embodiments of the present utility model, and the control device is respectively connected with the injection source and the photoelectric oscillator, and is used for controlling the phase locking of the output signal to the second signal.

Specifically, for the working principle of the control system in the embodiment of the present invention, reference may be made to the description of the control device in the above embodiments, and details are not repeated here.

According to the embodiment of the present invention, the signal of the injection source is divided into two parts, one part is injected into the OEO, while ensuring the low phase noise (short-term stability) of the OEO oscillating signal, its single-mode output is guaranteed, and the other part is used as a reference signal, through mixing The long-term stability of the OEO output signal is controlled by frequency detection and phase detection, thereby solving the problem of low long-term stability of the photoelectric oscillator in the prior art, and achieving the effect of controlling the long-term stability of the OEO output signal.

The control device can not only control the stability of the primary injection-locked OEO, but also realize the stability control of the secondary or even more injection-locked OEO.

Fig. 2 is a schematic diagram of a photoelectric oscillator control system according to an embodiment of the present invention. As shown in Figure 2, the optoelectronic oscillator comprises a first optoelectronic oscillator (i.e. long optical fiber ring OEO1) and a second optoelectronic oscillator (long optical fiber ring OEO2), the output terminal of the first optoelectronic oscillator is connected to the second optoelectronic oscillator The input terminal is connected, and the control device includes a first control device and a second control device, wherein the first control device is respectively connected with the injection source and the first photoelectric oscillator, and is used to control the phase of the output signal of the first photoelectric oscillator Locking on the second signal; the first control device is connected to the output terminal of the first photoelectric oscillator and the second photoelectric oscillator respectively, and is used to control the phase locking of the output signal of the second photoelectric oscillator to the first photoelectric oscillator on the output signal. Wherein, the output signal of the second photoelectric oscillator is the final output signal.

Another embodiment, as shown in FIG. 2 , uses two control devices (a first control device and a second control device) to control the stability of the secondary injection-locked OEO. The phase noise of the long fiber ring OEO output signal is related to the phase noise of the injected signal. The lower the phase noise of the injected signal, the better the lower phase noise output of the long fiber ring OEO. Multiple injections are used to further reduce the phase noise of the injected signal. . Figure 2 shows the secondary injection-locked OEO structure. A stable injection source is used to inject and lock the long optical fiber ring OEO1, combined with a stability control device to achieve a stable, single-mode, low-phase-noise secondary injection source, and then the injection-locked long The optical fiber ring OEO2, combined with the second stability control device, finally achieves a stable, single-mode, and lower phase noise output signal.

The above are only preferred embodiments of the utility model, and are not intended to limit the utility model. For those skilled in the art, the utility model can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present utility model shall be included in the protection scope of the present utility model.

Claims (8)

1. A control device for an optoelectronic oscillator, characterized in that the optoelectronic oscillator is connected to an injection source, and the injection source is used to output a first signal to the optoelectronic oscillator and output a second signal , wherein the control device includes: a phase shifter, connected to the injection source, for phase shifting the second signal; an acquisition unit connected to the output terminal of the optoelectronic oscillator and used to acquire the feedback signal coupled from the output signal of the optoelectronic oscillator; a mixer, connected to the phase shifter and the acquisition unit respectively, and used for performing phase discrimination on the phase-shifted second signal and the feedback signal; A servo module, connected to the mixer and the photoelectric oscillator, is used to control the phase of the output signal of the photoelectric oscillator to be locked to the second signal according to the phase-discriminated signal. 2. The control device according to claim 1, wherein the photoelectric oscillator has a built-in voltage-controlled phase shifter, the servo module is connected to the voltage-controlled phase shifter, and the servo module is used for The phase of the output signal of the photoelectric oscillator is controlled to be locked on the second signal by changing the voltage of the voltage-controlled phase shifter. 3. The control device according to claim 2, wherein the servo module is also used to amplify the signal after phase detection, and control the magnitude of the voltage fluctuation of the feedback signal after phase detection to just cover the voltage Control the phase shift range of the phase shifter from 0 to 360 degrees. 4. The control device according to claim 1, wherein the control device further comprises: a first microwave amplifier, connected between the phase shifter and the mixer, and used to amplify the phase-shifted second signal; The second microwave amplifier is connected between the acquisition unit and the mixer, and is used for amplifying the feedback signal. 5. The control device according to claim 1, wherein the control device further comprises: A low-pass filter, connected between the mixer and the servo module, is used for low-pass filtering the phase-discriminated signal. 6 . The control device according to claim 1 , characterized in that, the angle at which the phase shifter shifts the phase of the second signal is 90 degrees. 7. A photoelectric oscillator control system, characterized in that, comprising: an injection source for outputting the first signal and the second signal; an optoelectronic oscillator, connected to the injection source, for receiving the first signal, and obtaining an output signal from the first signal; A control device, the control device is the control device according to any one of claims 1 to 6, which is respectively connected to the injection source and the photoelectric oscillator, and is used to control the phase locking of the output signal at the above the second signal. 8. The photoelectric oscillator control system according to claim 7, wherein the photoelectric oscillator comprises a first photoelectric oscillator and a second photoelectric oscillator, the output terminal of the first photoelectric oscillator is connected to the The input end of the second photoelectric oscillator is connected, and the control device includes a first control device and a second control device, wherein, The first control device is respectively connected to the injection source and the first photoelectric oscillator, and is used to control the phase locking of the output signal of the first photoelectric oscillator to the second signal; The first control device is respectively connected to the output terminal of the first photoelectric oscillator and the second photoelectric oscillator, and is used to control the phase locking of the output signal of the second photoelectric oscillator to the first on the output signal of the optoelectronic oscillator.