Frequency hopping signal generation device and method
By integrating mutual injection semiconductor lasers and photoelectric feedback optimization systems, the problems of limited frequency points and difficult frequency tuning of frequency hopping signal generators in the prior art are solved, and high-purity, fast frequency hopping and large bandwidth signal generation is achieved, and it is suitable for high-speed communication and high-precision radar applications.
Patent Information
- Application Number
- CN202510188956.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-02-20
- Publication Date
- 2025-05-13
AI Technical Summary
In the prior art, frequency hopping signal generators have problems such as limited frequency points, difficult frequency tuning, complex device structure, high power consumption, expensive price, difficult integration, and poor frequency hopping signal quality, which cannot meet the needs of future high-speed communication and high-precision radar.
The integrated mutual injection semiconductor laser, optical beam splitter, first photodetector and frequency hopping feedback optimization system are adopted. The frequency hopping optical signal is divided into two beams through the optical beam splitter. The photoelectric conversion is directly realized by the first photodetector, and the signal optimization is performed through the frequency hopping feedback optimization system to form a feedback loop to improve signal purity.
It realizes the generation of frequency hopping signals with high purity, fast frequency hopping and large bandwidth. The device is exquisitely structured, easy to integrate, low cost and high flexibility, and can meet the needs of high-speed communication and high-precision radar.
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Figure CN119994633A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the field of microwave optoelectronic technology, and in particular to a frequency hopping signal generating device and method. Background Art
[0002] Frequency-hopping (FH) technology is widely used in radar, communication and other applications. In communication systems, the use of frequency-hopping technology can enhance network capacity, improve security and anti-interference capabilities. In radar systems, frequency-hopping microwave signals with large time-bandwidth products can increase radar detection accuracy. Traditional frequency-hopping source generation technology mainly relies on electronic equipment, and the generation method is mainly based on direct digital synthesizers or voltage-controlled oscillators in the electrical domain. However, these methods have an obvious drawback, that is, the frequency band and bandwidth of the generated frequency-hopping local oscillator source are limited, usually within 10 GHz, and due to the limitation of electronic bottlenecks, this drawback cannot be overcome through its own technical optimization. For future high-speed communications and high-precision radars, the frequency-hopping source generated by the above scheme is obviously not competent.
[0003] Microwave photonic technology can give full play to the characteristics of large bandwidth and strong resistance to electromagnetic interference of photonics, serve electronic technology, greatly improve the performance upper limit of electronic technology, break through the limitations of existing technologies, and has been widely studied. In 2014, Yao Jianping et al. proposed an optoelectronic oscillator technology based on an external modulator and a phase-shift grating to realize the frequency-hopping local oscillator source of high-purity and fast frequency-hopping microwave photonic technology. The realization of the frequency-hopping local oscillator in this scheme mainly depends on the change of polarization state, thereby realizing the hopping of microwave signals by changing the performance of microwave photonic filters. However, this scheme has the following two problems: first, the frequency hopping frequency is limited and can only change at two frequencies; second, the frequency hopping frequency is difficult to tune, mainly relying on the phase-shift grating. Once it is made, the response characteristics are difficult to tune. In recent years, there have also been reports on the generation of frequency-hopping local oscillator signals in the single-cycle oscillation state of optically injected semiconductor lasers. In 2016, Zhou Pei and others realized the generation of broadband frequency-hopping signals greater than 10 GHz based on a discrete light-injection semiconductor laser system by changing the voltage drive signal of the external modulator to control the intensity of the light signal injected into the slave laser. Compared with the above scheme, in principle, the frequency-hopping frequency can be arbitrarily controlled, which reflects great flexibility. However, this scheme has the following problems: First, the frequency-hopping signal generator is still based on a discrete light-injection semiconductor laser system, the device structure is complex, and an external modulator is required to change the intensity of the injected light signal, which has high power consumption, high price, and difficult integration; second, due to the influence of the inherent noise of the semiconductor laser, the frequency-hopping signal achieved by this technology has poor quality and high phase noise, and lacks corresponding phase noise improvement technology and means; third, the use of the polarization state controller increases the polarization sensitivity of the system, which is easily affected by external jitter, limiting its application scenarios. Summary of the invention
[0004] The purpose of the present invention is to overcome the deficiencies in the prior art and to provide a frequency hopping signal generating device and method, which have a compact structure, are easy to integrate, have low cost, and can generate a frequency hopping signal with high stability, high purity and large bandwidth.
[0005] To achieve the above object, the present invention is implemented by adopting the following technical solutions: In one aspect, the present invention provides a frequency hopping signal generating device, comprising an integrated mutual injection semiconductor laser, an optical beam splitter, a first photodetector and a frequency hopping feedback optimization system; The integrated mutual injection semiconductor laser operates in a single cycle dynamic state, the output end of the integrated mutual injection semiconductor laser is connected to the input end of the optical beam splitter, and the output end of the optical beam splitter is respectively connected to the input end of the first photodetector and the input end of the frequency hopping feedback optimization system; The delay of the frequency hopping feedback optimization system is the same as the period of the frequency hopping signal, and the output end of the frequency hopping feedback optimization system is connected to the input end of the integrated mutual injection semiconductor laser; wherein the frequency hopping signal is the signal output by the first photodetector.
[0006] Optionally, the frequency hopping feedback optimization system includes a single-mode optical fiber, an optical amplifier, and a second photodetector; The output end of the optical beam splitter is connected to the input end of the optical amplifier through a single-mode optical fiber, the output end of the optical amplifier is connected to the input end of the second photodetector, and the output end of the second photodetector is connected to the input end of the integrated mutual injection semiconductor laser.
[0007] Optionally, an optical isolator is provided at the output end of the integrated mutual injection semiconductor laser; The integrated mutual injection semiconductor laser comprises a front laser region and a rear laser region, wherein the front laser region and the rear laser region are integrated on the same active layer and share the same ridge waveguide structure; The front laser region and the rear laser region are in a short-coupled mutual injection state, and electrical etching is provided between the front laser region and the rear laser region.
[0008] Optionally, an arbitrary waveform generator is also included; generating a voltage signal with periodically varying amplitude in the arbitrary waveform generator according to a frequency hopping pattern; The voltage signal with periodic amplitude variation is transmitted to the metal electrode of the integrated mutual injection semiconductor laser.
[0009] Optionally, the total photoelectric delay is equal to an integer multiple of the period of the voltage signal with periodic amplitude variation generated by the arbitrary waveform generator.
[0010] Optionally, the gain of the frequency hopping feedback optimization system includes the gain of the optical amplifier and the gain brought by the modulation response enhancement effect of the integrated mutual injection semiconductor laser operating in a single-cycle dynamic state.
[0011] Optionally, the ratio of the first frequency-hopping optical signal to the second frequency-hopping optical signal is 1:9; wherein the first frequency-hopping optical signal is the signal output by the optical beam splitter to the first photodetector, and the second frequency-hopping optical signal is the signal output by the optical beam splitter to the frequency-hopping feedback optimization system.
[0012] In another aspect, the present invention provides a method for generating a frequency hopping signal, using the device described in the first aspect, comprising: Generate single-cycle frequency-hopping optical signals by integrating mutual injection semiconductor lasers; Splitting the frequency-hopping optical signal into two beams through an optical beam splitter to obtain a first frequency-hopping optical signal and a second frequency-hopping optical signal; Performing photoelectric conversion on the first frequency-hopping optical signal by a first photodetector to obtain a frequency-hopping signal; The second frequency-hopping optical signal is frequency-hopped feedback optimized by a frequency-hopping feedback optimization system to obtain a frequency-hopping electrical signal, and the frequency-hopping electrical signal is fed back to an integrated mutual injection semiconductor laser; wherein the delay of the frequency-hopping feedback optimization system is the same as the period of the frequency-hopping signal.
[0013] Compared with the prior art, the present invention has the following beneficial effects: 1. The present invention drives the integrated mutual injection semiconductor laser to work in a single-cycle dynamic state, and the generated single-cycle frequency hopping optical signal is divided into two by an optical beam splitter, wherein one frequency hopping optical signal is directly photoelectrically converted by a first photodetector, thereby obtaining the generation of a frequency hopping signal, and the other frequency hopping optical signal is purity-enhanced by a frequency hopping feedback optimization system, and electrically fed back to the integrated mutual injection semiconductor laser. Since a feedback loop is formed, the time delay of the feedback optimization system is exactly equal to the period of the frequency hopping signal, so that the frequency hopping signal can be optimized, and a high-purity, fast frequency hopping, and large-span fast frequency hopping signal can be generated, and the device has a compact structure, is easy to integrate, has low cost, and has high flexibility; 2. The present invention adopts an integrated mutual injection semiconductor laser to realize the generation of fast frequency hopping signals. The integrated mutual injection semiconductor laser highly integrates the discrete light injection semiconductor laser system, replaces the functions of the traditional external modulator, polarization controller, optical circulator, radio frequency filter and part of the electric radio frequency amplifier, and greatly simplifies the structure while reducing the volume, power consumption and cost; 3. The present invention divides the frequency-hopping optical signal into two beams through an optical beam splitter, wherein 90% of the optical signal is modulated back to the integrated mutual injection semiconductor laser through optical gain feedback. No electrical RF amplifier is used in the feedback modulation full link. The optical amplifier is used to provide partial gain and the modulation response enhancement gain provided by the single-cycle dynamic state of the integrated mutual injection semiconductor laser is used. This can achieve broadband gain that cannot be provided by the electrical RF amplifier. The difficult-to-tune RF filter function is replaced by the single-cycle modulation response enhancement characteristic of the integrated mutual injection semiconductor laser. The gain spectrum generated by the modulation response enhancement characteristic of the single-cycle dynamic state of the integrated mutual injection semiconductor laser is a high-gain narrowband. Therefore, in applications, the function of the RF filter can be achieved. 4. The present invention can realize the individual regulation of the front laser / rear laser on the integrated mutual injection semiconductor laser by controlling the bias current / voltage of the MHz order. By changing the current / voltage, the output light intensity and wavelength of the laser area can be changed, thereby changing the mutual injection parameters, including the detuning frequency and the coupling strength. The single cycle frequency realized based on the single cycle state is affected by the detuning frequency and the coupling strength, and can reach a signal frequency of 100 GHz, thereby realizing the generation of a frequency hopping signal with a bandwidth of 100 GHz, which greatly improves the anti-interference performance of the frequency hopping communication and the detection accuracy of the radar; 5. The present invention is based on a lightweight, miniaturized monolithic integrated mutual injection semiconductor laser combined with all-optical gain optoelectronic oscillator technology, which realizes the generation of large-span, high-purity, fast frequency-hopping signals for millimeter-wave radar applications. The implementation principle is simple, the structure is sophisticated, and it is suitable for popularization and use. BRIEF DESCRIPTION OF THE DRAWINGS
[0014] Figure 1 FIG. 1 is a schematic diagram of the structure of a frequency hopping signal generating device in one embodiment of the present invention; Figure 2 FIG. 1 is a schematic diagram showing the structure of a frequency hopping signal generating device in another embodiment of the present invention; Figure 3 The figure shows a schematic diagram of the spectrum generated by two loops when the frequency hopping signal generating device of the present invention starts oscillating in one embodiment; Figure 4 Shown Figure 3 Enlarged view of (a) in the middle; Figure 5 Shown Figure 3 Enlarged view of (b) in the middle; Figure 6 The figure shows a time-frequency diagram obtained by short-time Fourier transforming the timing waveform of the frequency-hopping signal generated by the frequency-hopping signal generating device in one embodiment of the present invention. DETAILED DESCRIPTION
[0015] The technical solution of the present invention is described in detail below through the accompanying drawings and specific embodiments. It should be understood that the embodiments of the present invention and the specific features in the embodiments are detailed descriptions of the technical solution of the present invention, rather than limitations on the technical solution of the present invention. The embodiments of the present invention and the technical features in the embodiments may be combined with each other unless there is a conflict.
[0016] The term "and / or" is only a description of the association relationship between related objects, indicating that there can be three relationships. For example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " generally indicates that the related objects are in an "or" relationship.
[0017] Example 1
[0018] like Figure 1 As shown, this embodiment introduces a frequency hopping signal generating device, including an arbitrary waveform generator, an integrated mutual injection semiconductor laser, an optical beam splitter, a first photodetector and a frequency hopping feedback optimization system, wherein the frequency hopping feedback optimization system includes a single-mode optical fiber, an optical amplifier, and a second photodetector.
[0019] The output end of the integrated mutual injection semiconductor laser is connected to the input end of the optical beam splitter, and the output end of the optical beam splitter is respectively connected to the input end of the first photodetector and the input end of the frequency hopping feedback optimization system; The input end and the output end of the frequency hopping feedback optimization system are connected in sequence to a single-mode optical fiber, an optical amplifier, and a second photodetector; The output end of the frequency hopping feedback optimization system is connected to the input end of the integrated mutual injection semiconductor laser; The output end of the optical beam splitter is connected to the input end of the optical amplifier through a single-mode optical fiber, the output end of the optical amplifier is connected to the input end of the second photodetector, and the output end of the second photodetector is connected to the input end of the integrated mutual injection semiconductor laser.
[0020] The integrated mutual injection semiconductor laser operates in a single-cycle dynamic state to generate a single-cycle frequency-hopping optical signal, and sends the frequency-hopping optical signal to an optical beam splitter; The optical beam splitter divides the frequency-hopping optical signal into two beams to obtain a first frequency-hopping optical signal and a second frequency-hopping optical signal, sends the first frequency-hopping optical signal to the first photodetector, and sends the second frequency-hopping optical signal to the optical amplifier through the single-mode optical fiber; The first photoelectric detector performs photoelectric conversion on the first frequency-hopping optical signal to obtain a frequency-hopping signal; The optical amplifier performs power amplification on the second frequency-hopping optical signal to obtain a third frequency-hopping optical signal, and sends the third frequency-hopping optical signal to the second photodetector; The second photodetector performs photoelectric conversion on the third frequency-hopping optical signal to obtain a frequency-hopping electrical signal, and feeds the frequency-hopping electrical signal back to the integrated mutual injection semiconductor laser.
[0021] The local oscillator of the fast frequency hopping signal is directly generated by the nonlinear dynamic state of the integrated mutual injection semiconductor laser. The driving current or driving voltage of the integrated mutual injection semiconductor laser is approximately linearly related to the single-cycle frequency of the single-cycle dynamic state, such as Figure 2 As shown, a voltage signal whose amplitude jumps periodically with time (such as Costas shape) is generated in the arbitrary waveform generator according to the frequency hopping pattern, and is transmitted to the metal electrode of the integrated mutual injection semiconductor laser through a DC wire, so that the Costas-shaped jump of frequency, that is, the generation of a frequency hopping signal, can be achieved. Moreover, since the response time of photons and electrons in the integrated mutual injection semiconductor laser is short, the generation of a fast frequency hopping signal with a frequency hopping rate of the MHz order of magnitude can be easily achieved.
[0022] The integrated mutual injection semiconductor laser operates in a single-cycle dynamic state by controlling the current, and the output frequency-hopping optical signal is divided into two beams by an optical beam splitter, wherein a 10% frequency-hopping optical signal directly passes through the first photodetector and is converted to realize the generation of the frequency-hopping signal. Since the feedback system is not introduced at this time, the signal purity of the frequency-hopping signal is low. The other 90% frequency-hopping optical signal passes through the single-mode optical fiber, the optical amplifier, and the second photodetector in sequence and is fed back to be directly modulated back to the integrated mutual injection semiconductor laser. This branch closed loop realizes the frequency-hopping signal photoelectric feedback optimization system to improve the quality of the first branch frequency-hopping signal. Since a feedback loop is formed, the time delay of the feedback optimization system is exactly equal to the period of the frequency-hopping signal, so that the frequency-hopping signal can be optimized, and a high-purity, fast-frequency-hopping, large-span fast-frequency-hopping signal can be generated. In addition, the device has a compact structure, is easy to integrate, has low cost, and is highly flexible.
[0023] The integrated mutual injection semiconductor laser is an integrated short-coupled mutual injection semiconductor laser system, which mainly includes two parts, the front laser area and the rear laser area. The front laser area and the rear laser area are integrated on the same active layer and share the same ridge waveguide structure. There is a 90° phase shift in the middle position of the front laser area and the rear laser area to ensure the single-mode lasing of each laser area. There is no optical isolator between the front laser area and the rear laser area, which is in a short-coupled mutual injection state. The front laser and the rear laser are electrically etched to ensure independent current tuning and reduce crosstalk. Therefore, the two laser areas are in a short-coupled mutual injection system. When the current of one of the laser areas changes, the corresponding mutual injection coupling strength and detuning frequency will also change. An optical isolator is provided at the light outlet, that is, the output end, of the integrated mutual injection laser.
[0024] By controlling the bias current / voltage, the front laser / rear laser on the integrated mutual injection semiconductor laser can be individually regulated. By changing the current, the output light intensity and wavelength of the laser area can be changed, thereby changing the mutual injection parameters, including the detuning frequency and the coupling strength. The single-cycle frequency achieved based on the single-cycle state is affected by the detuning frequency and the coupling strength, and can reach a signal frequency of hundreds of GHz, thereby realizing the generation of frequency-hopping signals with a bandwidth of hundreds of GHz, which greatly improves the anti-interference performance of frequency-hopping communication and the detection accuracy of radar.
[0025] The integrated mutual injection semiconductor laser highly integrates the discrete light injection semiconductor laser system, replacing the functions of the traditional external modulator, polarization controller, optical circulator, RF filter and part of the electrical RF amplifier, greatly simplifying the structure while reducing the size, power consumption and cost.
[0026] In the frequency hopping feedback optimization system, the optoelectronic feedback link transmits not a single-frequency optical / electrical frequency hopping signal, but a periodic fast frequency hopping optical / electrical signal. By controlling the delay of the optoelectronic feedback link to be consistent with the period of the generated frequency hopping signal (unpurified frequency hopping signal and purified frequency hopping signal), it is possible to ensure that the signal of the optoelectronic feedback link is consistent with the single-period dynamic state inside the integrated mutual injection semiconductor laser, thereby achieving sideband injection locking, ensuring phase synchronization, and achieving fast frequency hopping signal generation.
[0027] No electrical RF amplifier is used in the optoelectronic feedback link. An optical amplifier is used to provide partial gain, and the modulation response enhancement gain provided by the single-cycle dynamic state of the integrated mutual injection semiconductor laser is used. This can achieve broadband gain that the electrical RF amplifier cannot provide. The difficult-to-tune RF filter function is replaced by the single-cycle modulation response enhancement characteristic of the integrated mutual injection semiconductor laser. The gain spectrum generated by the modulation response enhancement characteristic of the single-cycle dynamic state of the integrated mutual injection semiconductor laser is a high-gain narrowband. Therefore, in applications, the function of the RF filter can be realized.
[0028] The total photoelectric delay of the single-mode optical fiber, the photodetector and the jumpers between the connectors is equal to an integer multiple of the period of the voltage signal whose amplitude output by the arbitrary waveform generator jumps periodically with time (such as Costas shape), which can ensure the frequency alignment of the photoelectric feedback link during the modulation of the integrated mutual injection semiconductor laser, thereby improving the purity of the frequency hopping signal.
[0029] The frequency hopping feedback optimization system includes a single-mode optical fiber, an optical amplifier, and a second photodetector. The photoelectric feedback delay consists of two parts: electrical delay and optical delay. The optical delay includes the transmission delay of the optical beam splitter and the single-mode optical fiber, the response delay of the optical amplifier and the second photodetector, and the electrical delay includes the signal radio frequency cable transmission feedback of the photoelectric feedback link to the integrated mutual injection semiconductor laser modulation port.
[0030] The improvement of frequency-hopping signal purity is based on the all-optical gain mechanism, which uses broadband optical amplifiers (THz level) to replace traditional narrowband electrical gain amplifiers (GHz level), thereby breaking through the limitations of traditional optoelectronic oscillators on the electrical bandwidth of feedback signals.
[0031] The gain provided by the optoelectronic feedback link comes entirely from optical gain, which includes the gain of the optical amplifier and the gain brought by the modulation response enhancement effect provided by the integrated mutual injection semiconductor laser working in a single-cycle dynamic state. This can greatly improve the efficiency of electro-optical modulation. Theoretically, the above optical gain does not have the narrow bandwidth limitation of an electrical RF amplifier, and can break through the frequency and bandwidth limitations of the signal generated by the traditional electrical optoelectronic oscillator.
[0032] This embodiment is based on a lightweight, miniaturized monolithic integrated mutual injection semiconductor laser combined with an all-optical gain optoelectronic oscillator technology, and realizes the generation of large-span, high-purity, fast frequency-hopping signals for millimeter-wave radar applications. The implementation principle is simple, the structure is sophisticated, and it is suitable for popularization and use.
[0033] Example 2
[0034] Based on the same inventive concept as that of Embodiment 1, this embodiment introduces a method for generating a frequency hopping signal, including: A bias voltage with a Costas-like periodic amplitude variation is applied to the integrated mutual injection semiconductor laser, so that the integrated mutual injection semiconductor laser operates in a single-cycle state to generate a single-cycle state optical signal with a Costas-like frequency hopping.
[0035] The single-cycle nonlinear dynamic state is a nonlinear dynamic effect generated in an integrated mutual injection semiconductor laser. When the Bragg wavelengths of the front / rear laser regions are similar, their lasing wavelengths are controlled by current, and under the condition of mutual injection, the two laser regions of the integrated mutual injection semiconductor laser will enter the single-cycle state at the same time; when the frequency-hopping single-cycle state optical signal enters the photoelectric detector for photoelectric conversion, a frequency-hopping signal can be obtained, and its hopping mode is the same as the bias current or voltage mode that drives the integrated mutual injection semiconductor laser, which is also similar to the Costas shape, and the microwave frequency output at each moment, that is, the single-cycle oscillation frequency is equal to the difference in the frequency of the frequency-hopping optical signals output by the front and rear laser regions under the mutual injection state.
[0036] Through the optical beam splitter, 1 / 10 of the frequency-hopping optical signal output by the integrated mutual injection semiconductor laser is used to generate a frequency-hopping signal through the first photodetector. At this time, the purity of the frequency-hopping signal is low because the frequency modulation feedback optimization system is not introduced; 9 / 10 of the optical signal output by the integrated mutual injection semiconductor laser is transmitted over a long distance through a single-mode optical fiber, and power amplified through an optical amplifier, and input into the second photodetector to obtain a frequency-hopping electrical signal, which is fed back and directly modulated to the integrated mutual injection semiconductor laser; since a feedback loop is formed and the feedback loop delay is made exactly equal to the period of the frequency-hopping signal, the frequency-hopping signal can be optimized.
[0037] The integrated mutual injection semiconductor laser has a single-cycle dynamic state inside, which can suppress the damped oscillation inside the integrated mutual injection semiconductor laser and improve the modulation response of the integrated mutual injection semiconductor laser at the single-cycle frequency.
[0038] Therefore, when the delay of the optoelectronic feedback link is adjusted to be consistent with the period of the frequency hopping drive signal / pattern, the RF frequency modulated to the integrated mutual injection semiconductor laser is exactly equal to the frequency difference of the output optical signal of the integrated mutual injection semiconductor laser at that moment, thereby obtaining a modulation response enhancement, and based on the sideband injection locking effect, the phase locking of the two output optical signals is achieved. Based on this effect, in this embodiment, gain and phase locking can be provided to the optoelectronic feedback link at the same time, thereby improving the purity of the output frequency hopping signal.
[0039] By inputting a square wave signal with a period of 1us, the output can be Figure 3 The output waveform shown shows a periodic change, and the repetition period corresponds to the period of the input square wave signal. Figure 3 Some time domain waveforms in Figure 4 , 5 As shown in the figure, in each repetition cycle, the time interval between adjacent peaks at the start and end of each cycle in the first half of the time is 54.55 ps, and the interval between adjacent peaks at the start and end of each cycle in the second half of the time is 100.33 ps, corresponding to single-cycle oscillations of 18.33 GHz and 9.967 GHz, respectively. Of course, it can be found that when the optical signal oscillates at different frequencies, its oscillation amplitude is different, which is mainly due to the dynamic competition between the two oscillating cavity modes in the single-cycle dynamic state under the condition of integrated mutual injection.
[0040] Performing a short-time Fourier transform on the time domain waveform, we can get the following Figure 6 The frequency-time variation curve shown in the figure has different colors corresponding to different power intensities. It can be found from the figure that the output time domain signal oscillates at two fixed frequencies, and its corresponding time distribution is exactly the same as the above analysis. Figure 4 ,5 , it can also be found that the switching time from high frequency to low frequency is about 124.4 ps, and the switching time from low frequency to high frequency is 65.8 ps. Therefore, it can be determined that the high-speed frequency switching characteristics based on the single-cycle oscillation effect of the integrated mutual injection semiconductor laser have a switching time of 124.2 ps, and the corresponding switching frequency is about 8 GHz. This parameter shows that under the condition that the modulation frequency is less than the switching frequency, the integrated mutual injection semiconductor laser can achieve fast and stable switching between different single-cycle signals.
[0041] The embodiments of the present invention are described above in conjunction with the accompanying drawings, but the present invention is not limited to the above-mentioned specific implementation methods. The above-mentioned specific implementation methods are merely illustrative and not restrictive. Under the enlightenment of the present invention, ordinary technicians in this field can also make many forms without departing from the scope of protection of the purpose of the present invention and the claims, which all fall within the protection of the present invention.
Claims
1. A frequency hopping signal generating device, characterized in that: It includes an integrated mutual injection semiconductor laser, an optical beam splitter, a first photodetector and a frequency hopping feedback optimization system; The integrated mutual injection semiconductor laser operates in a single cycle dynamic state, the output end of the integrated mutual injection semiconductor laser is connected to the input end of the optical beam splitter, and the output end of the optical beam splitter is respectively connected to the input end of the first photodetector and the input end of the frequency hopping feedback optimization system; The delay of the frequency hopping feedback optimization system is the same as the period of the frequency hopping signal, and the output end of the frequency hopping feedback optimization system is connected to the input end of the integrated mutual injection semiconductor laser; wherein the frequency hopping signal is the signal output by the first photodetector.
2. The frequency hopping signal generating device according to claim 1, characterized in that: The frequency hopping feedback optimization system includes a single-mode optical fiber, an optical amplifier and a second photodetector; The output end of the optical beam splitter is connected to the input end of the optical amplifier through a single-mode optical fiber, the output end of the optical amplifier is connected to the input end of the second photodetector, and the output end of the second photodetector is connected to the input end of the integrated mutual injection semiconductor laser.
3. The frequency hopping signal generating device according to claim 1, characterized in that: An optical isolator is provided at the output end of the integrated mutual injection semiconductor laser; The integrated mutual injection semiconductor laser comprises a front laser region and a rear laser region, wherein the front laser region and the rear laser region are integrated on the same active layer and share the same ridge waveguide structure; The front laser region and the rear laser region are in a short-coupled mutual injection state, and electrical etching is provided between the front laser region and the rear laser region.
4. The frequency hopping signal generating device according to claim 1, characterized in that: Also included is an arbitrary waveform generator; generating a voltage signal with periodically varying amplitude in the arbitrary waveform generator according to a frequency hopping pattern; The voltage signal with periodic amplitude variation is transmitted to the metal electrode of the integrated mutual injection semiconductor laser.
5. The frequency hopping signal generating device according to claim 4, characterized in that: The total photoelectric delay is equal to an integer multiple of the voltage signal with periodic amplitude variation generated by the arbitrary waveform generator.
6. The frequency hopping signal generating device according to claim 2, characterized in that: The gain of the frequency hopping feedback optimization system includes the gain of the optical amplifier and the gain brought by the modulation response enhancement effect of the integrated mutual injection semiconductor laser working in a single-cycle dynamic state.
7. The frequency hopping signal generating device according to claim 1, characterized in that: The ratio of the first frequency-hopping optical signal to the second frequency-hopping optical signal is 1:9; wherein the first frequency-hopping optical signal is the signal output by the optical beam splitter to the first photodetector, and the second frequency-hopping optical signal is the signal output by the optical beam splitter to the frequency-hopping feedback optimization system.
8. A method for generating a frequency hopping signal, using the device according to any one of claims 1 to 7, characterized in that: include: Generate single-cycle frequency-hopping optical signals by integrating mutual injection semiconductor lasers; Splitting the frequency-hopping optical signal into two beams through an optical beam splitter to obtain a first frequency-hopping optical signal and a second frequency-hopping optical signal; Performing photoelectric conversion on the first frequency-hopping optical signal by a first photodetector to obtain a frequency-hopping signal; The second frequency-hopping optical signal is frequency-hopped feedback optimized by a frequency-hopping feedback optimization system to obtain a frequency-hopping electrical signal, and the frequency-hopping electrical signal is fed back to an integrated mutual injection semiconductor laser; wherein the delay of the frequency-hopping feedback optimization system is the same as the period of the frequency-hopping signal.