Magnetic control phonon frequency comb and generation device and method thereof

Abstract

The invention discloses a magnetic control phonon frequency comb and a generation device and method thereof, and belongs to the technical field of optical communication, a magnetostrictive resonator in a single mechanical mode is adopted to generate a phonon frequency comb under the driving of a double-pumping magnetic field, and the frequency comb positioned at a near-resonance pumping position is stably broadened along with the enhancement of a low-frequency pumping magnetic field, so that the frequency comb is converted into a frequency comb. And the phonon frequency combs which are close to half of the resonance pump frequency are switched for multiple times along with the enhancement of the low-frequency pumping magnetic field. The invention provides a phonon frequency comb based on a magnetostrictive macroresonator, and experiments prove that the phonon frequency comb is based on the magnetostrictive macroresonator. The basic telescopic mechanical mode forms a comb-shaped frequency spectrum under the action of a double-pumping magnetic field. According to the invention, a novel magnetic-mechanical frequency comb is provided for sensing, timing and metering application, and the size of the magnetostrictive mechanical resonator is in a macroscopic scale and reaches a centimeter level, so that the magnetostrictive mechanical resonator is convenient to manufacture; meanwhile, the device does not need precise electrode contact and expensive precise laser detection, and the application scene of the phonon frequency comb is greatly enhanced through the advantages.

Description

Technical Field

[0001] The present invention belongs to the technical field of optical communication, and particularly relates to a magnetically controlled phonon frequency comb and its generating device and method. Background Art

[0002] Optical frequency combs have had a huge impact, shaping various fields from metrology to astronomy. An optical frequency comb is a broadband spectrum composed of a series of discrete and equally spaced frequency components, which appears as an optical frequency sequence with equal frequency intervals in the frequency domain. Optical frequency combs mainly focus on the electromagnetic wave frequency band. When facing lower frequency bands, new systems need to be introduced to expand the frequency band. Phonons and photons both belong to bosons and have high similarity.

[0003] Phonon frequency combs, also known as acoustic or mechanical frequency combs, have been realized by driving electromechanical resonators based on the piezoelectric principle and cavity electromechanical devices based on Kerr-like nonlinearity. The phonon frequency combs generated by them require direct contact of electrodes or precise laser detection. Their complexity, the requirement for designing specific mode structures, very high threshold powers, and the possible need for additional laser sources limit the application of these systems.

[0004] So far, there has been no report on generating phonon frequency combs by using a magnetic field to manipulate magnetostrictive resonators. Magnetostrictive resonators have very strong fundamental vibration modes under a suitable bias static magnetic field. This mode is easily driven into a non-linear vibration state by a near-resonant pumping magnetic field. At this time, the additionally applied low-frequency pump interacts with the main vibration through the three-wave mixing mechanism, generating a series of equally spaced comb-shaped spectral lines. In addition, when the near-resonant pump drives the resonator into a period-doubling bifurcation vibration, the low-frequency vibration driven by the low-frequency pump also interacts with this period-doubling vibration, generating a set of combs centered on the period-doubling vibration. This phonon frequency comb will repeatedly switch between two comb-shaped modes by half the number of comb teeth as the low-frequency pump is enhanced. The precise manipulation of the half number of teeth of the phonon frequency comb based on a single mechanical mode has not been reported yet. Summary of the Invention

[0005] The technical problem solved by the present invention: Provide a magnetically controlled phonon frequency comb and its generating device and method.

[0006] Technical Solution: To solve the above technical problem, the technical solution adopted by the present invention is as follows:

[0007] A magnetically controlled phonon frequency comb uses a magnetostrictive resonator with a single mechanical mode to generate a comb-shaped spectrum through three-wave mixing under the drive of a double-pump magnetic field, thereby generating a phonon frequency comb.

[0008] Furthermore, a switchable phonon frequency comb is realized by suppressing period-doubling bifurcation, and this phonon frequency comb can switch the half number of teeth at a constant comb tooth spacing.

[0009] Furthermore, when the near-resonant pump V p is low, the tooth pitch is equal to f s and the frequency comb tooth coverage band of f s steadily increases with the increase of the low-frequency pump V

[0010] Furthermore, when the near-resonant pump V p increases to the double-period vibration threshold of the first vibration mode, due to period-doubling bifurcation and three-wave mixing, as the low-frequency pump V s increases, an additional comb structure appears.

[0011] A device for generating a magneto-controlled phonon frequency comb, characterized in that it comprises a magnetostrictive resonator with dimensions of 15 mm × 4 mm × 25 μm, three induction coils respectively for sensing, low-frequency pumping and near-resonant pumping, an electromagnet, a function waveform generator, a lock-in amplifier and a power amplifier; the lock-in amplifier and the power amplifier apply a low-frequency magnetic field; the function waveform generator provides a sinusoidally varying field.

[0012] Furthermore, the induction coil converts the magnetic field excited by the resonator vibration into an electrical signal, inputs it into a vector network analyzer or a lock-in amplifier, and then performs time-domain and frequency-domain post-processing on the response measured by the lock-in amplifier to obtain the frequency-domain response of the resonator.

[0013] Furthermore, a driving magnetic field is applied longitudinally:

[0014] ,

[0015] wherein, H p represents the total applied driving magnetic field; H dc represents the static magnetic field applied longitudinally, applied by the electromagnet; h p is the sinusoidally varying field provided by the function waveform generator; f p is the frequency of the near-resonant pump V p ; t represents time. A low-frequency magnetic field is applied:

[0016] ,

[0017] The low-frequency magnetic field H s is applied through the lock-in amplifier and the power amplifier; f s represents the frequency of the low-frequency pump V s ; h s is the low-frequency sinusoidally varying field provided by the lock-in amplifier and the power amplifier; t represents time.

[0018] A method for generating a magnetically controlled phonon frequency comb, characterized in that: a magnetostrictive resonator with a single mechanical mode generates a phonon frequency comb under the drive of a dual-pump magnetic field, and the frequency comb located at the near-resonant pump broadens stably as the low-frequency pump magnetic field increases, while the phonon frequency comb located at half of the near-resonant pump frequency switches multiple times as the low-frequency pump magnetic field increases.

[0019] Further, in the PD bifurcation state, a low-frequency pump V is applied s , a comb-shaped spectrum appears at the near-resonant frequency, and the coverage band of this frequency comb increases with the increase of V s , and the frequency comb generated at continuously switches between two modes.

[0020] Further, mode , mode , where n is a positive integer; under the increase of the low-frequency pump magnetic field, the frequency comb switches between M1 and M2.

[0021] Beneficial effects: Compared with the prior art, the present invention has the following advantages:

[0022] The present invention discloses a device and method for generating a magnetically controlled phonon frequency comb based on a magnetostrictive mechanical resonator. A phonon frequency comb based on a magnetostrictive macroscopic resonator is proposed and experimentally demonstrated. The basic stretching mechanical mode undergoes three-wave mixing under the action of a dual-pump magnetic field, thereby forming a comb-shaped spectrum. In addition, a novel switchable phonon frequency comb by suppressing period-doubling bifurcation is proposed, and this phonon frequency comb can switch half the number of teeth at a constant comb tooth spacing. Experiments show that the formation, evolution, and switching of the phonon frequency comb in the period-doubling bifurcation state are related to the Duffing nonlinear mechanism.

[0023] The discovery of the present invention provides a novel magneto-mechanical frequency comb for sensing, timing, and metrology applications. The magnetostrictive mechanical resonator used has a macroscopic scale size, reaching the centimeter level, so it is convenient to manufacture; at the same time, the device of the present invention does not require precise electrode contact, nor expensive precise laser detection, and these advantages greatly enhance the application scenarios of the phonon frequency comb. Description of the Drawings

[0024] Figure 1 is a conceptual diagram of the formation and evolution of a magneto-acoustic phonon frequency comb;

[0025] Figure 2 is the experimental setup of a magneto-mechanical phonon frequency comb;

[0026] Figure 3 In (a), the first mechanical resonance frequency of the resonator and S are measured under static magnetic fields H of different intensities dc , 11Reflection coefficient values, and the green dashed line represents the bias static magnetic field corresponding to subsequent experiments .(b) Measured S spectrum of the resonator at 11 . The inset shows a numerical finite element simulation of the first vibration mode, and the color represents the stress distribution. (c) Contour plot of the mechanical resonator response when increasing the pump voltage V p at near-resonant frequencies. The color bar represents the amplitude in dBV. (d) Three typical spectral lines extracted from (c), namely single-period oscillation at low-frequency pump voltage , bias static magnetic field , PD bifurcation and chaos .

[0027] Figure 4 is the variation of the spectrum with the intensity of the low-frequency pump voltage V s when the resonator is in the period-doubling bifurcation vibration state.

[0028] Figure 5 In (a), continuous-scan spectrogram at half of the near-resonant pump frequency (75 kHz). (b) Three arrows in the figure mark the changes in the amplitudes of three comb teeth. . Two background colors represent the regions where the M1 and M2 modes exist respectively.

[0029] Figure 6 is the evolution of the comb structure at half of the near-resonant pump frequency (75 kHz) measured at different low-frequency pump voltages under detuning. . (b), (d), (f) are the amplitude changes of the three teeth marked by the three arrows in (a), (c), (e) respectively. . Two background colors represent the regions where the M1 and M2 modes exist respectively. Detailed implementation manners

[0030] The following further clarifies the present invention in conjunction with specific embodiments. The embodiments are implemented on the premise of the technical solution of the present invention. It should be understood that these embodiments are only used to illustrate the present invention and not to limit the scope of the present invention.

[0031] Embodiment 1

[0032] This embodiment provides a magneto-controlled phonon frequency comb. A magnetostrictive resonator with a single mechanical mode generates a comb-shaped spectrum through three-wave mixing under the drive of a dual-pump magnetic field, thereby generating a phonon frequency comb.

[0033] The switchable phonon frequency comb is realized by suppressing period-doubling bifurcation, and the phonon frequency comb can switch the number of half teeth at a constant comb tooth spacing. When the near-resonant pump V pWhen it is low, the tooth pitch is equal to f s The frequency comb tooth coverage band of s increases steadily with the increase of the low-frequency pump V p When the near-resonant pump V s increases to the double-period vibration threshold of the first vibration mode, due to period-doubling bifurcation and three-wave mixing, with the increase of the low-frequency pump V

[0034] As Figure 1 shown, it is a mechanical system with a single vibration mode f 0 By applying two pump magnetic fields, namely a near-resonant pump V with a frequency of f p (≈f 0 ) and a weaker low-frequency pump V with a frequency of f p and f s respectively, the system will enter the nonlinear dynamic region. s

[0035] When the near-resonant pump V p is low, the tooth coverage band of the frequency comb with a tooth pitch equal to f s increases steadily with the increase of the low-frequency pump V s This frequency comb is described in the form of where mf p represents the order and center of the m-th comb, and n and f s represent the n-th tooth and the tooth pitch of the comb, as shown by the dashed box in Figure 1

[0036] When the near-resonant pump V p increases to the double-period vibration threshold of the first vibration mode, due to period-doubling bifurcation and three-wave mixing, with the increase of the low-frequency pump V s an additional comb structure appears, which is described as (Spectrum 2). Continuing to increase the low-frequency pump V p under a constant near-resonant pump V s , the comb structure converts to (Spectrum 4), accompanied by a short-term superposition (Spectrum 3). During this process, the coverage band of the phonon frequency comb centered on f p increases steadily.

[0037] Embodiment 2

[0038] This embodiment provides a device for generating a magneto-controlled phonon frequency comb. The architecture of the device is as shown in Figure 2 ​​As shown, the device includes a magnetostrictive resonator with dimensions of 15 mm × 4 mm × 25 μm, three induction coils for sensing, low-frequency pumping, and near-resonant pumping respectively, an electromagnet for applying a static magnetic field, a function waveform generator, a lock-in amplifier, and a power amplifier. Among them, the three induction coils are arranged outside the resonator along the length from the inside to the outside for sensing, low-frequency pumping, and near-resonant pumping respectively. A low-frequency magnetic field is applied through the lock-in amplifier and the power amplifier; the function waveform generator provides a sinusoidally varying field.

[0039] The resonator in this embodiment uses the AYFA-M model iron-based amorphous alloy material (Metglas) of Qingdao Yunlu Advanced Materials Technology Co., Ltd. as the raw material. It is processed and cut using a fiber laser device, and the fabricated resonator has dimensions of 15 mm × 4 mm × 25 μm.

[0040] As Figure 2 shown, three coils are arranged outside the resonator along the length from the inside to the outside for sensing, low-frequency pumping, and near-resonant pumping respectively. A driving magnetic field is applied longitudinally:

[0041] ,

[0042] where H p represents the total applied driving magnetic field; H dc represents the static magnetic field applied longitudinally by the electromagnet; h p is the sinusoidally varying field provided by the function waveform generator; f p is the frequency of the near-resonant pump V p ; t represents time.

[0043] Another low-frequency magnetic field is:

[0044] ,

[0045] The low-frequency magnetic field H s is applied through the lock-in amplifier and the power amplifier; f s represents the frequency of the low-frequency pump V s ; h s is the low-frequency sinusoidally varying field provided by the lock-in amplifier and the power amplifier; t represents time.

[0046] The induction coil converts the magnetic field excited by the resonator vibration into an electrical signal and inputs it into a vector network analyzer (VNA) or a lock-in amplifier. Using LabView software, the response measured by the lock-in amplifier is post-processed in the time domain and the frequency domain to obtain the frequency domain response of the mechanical resonator.

[0047] Embodiment 3

[0048] This embodiment provides a method for generating a magnetically controlled phonon frequency comb. A magnetostrictive resonator with a single mechanical mode generates a phonon frequency comb under the drive of a dual-pump magnetic field. The frequency comb near the near-resonant pump steadily broadens as the low-frequency pump magnetic field increases, while the phonon frequency comb at half of the near-resonant pump frequency undergoes multiple switches as the low-frequency pump magnetic field increases.

[0049] Place the resonator inside a solenoid connected to VNA - PORT1, and measure the resonant frequency and vibration amplitude of the resonator under different axial static magnetic fields. The resonant frequency f of the longitudinal vibration 0 is related to the Young's modulus of the Metglass material of the resonator, and the value of the Young's modulus can be changed by applying a static magnetic field. The experimental results are as Figure 3 (a) shows that as the magnetic field increases, the resonant frequency increases from 145 kHz to 159 kHz. When the external magnetic field is in the range of 10 - 20 Oe, the resonant frequency changes rapidly with the magnetic field.

[0050] The present invention selects the magnetic field to which the resonator is sensitive to external environmental changes, that is, 14.3 Oe, as the bias magnetic field for subsequent experiments. The present invention extracts the S 11 reflection coefficient spectrum, as Figure 3 (b), and it can be seen that the mechanical quality factor of the first mechanical mode is 109. Figure 3 The inset in (b) shows the numerical finite element simulation of this vibration mode.

[0051] Set the driving frequency f p to 150 kHz near f 0 and gradually increase the pump voltage V p , and the mechanical resonator will undergo period-doubling (PD) bifurcation until chaos. Figure 3 (c) is the measured spectrum sweep in the frequency - pump voltage V p plane. Initially, only a peak at is observed. When the pump voltage increases to more than 9 V, PD bifurcation occurs, and the response peak corresponds to , where m is a positive integer. Further increase the pump voltage to 20 V, and the resonant cavity enters the chaotic region. The typical spectra of the periodic motion, PD bifurcation, and chaotic state extracted from 3(c) are as Figure 3 (d) shows, corresponding to V p = 5 V, 15 V, and 30 V respectively.

[0052] Next, under the PD bifurcation state, apply a low - frequency pump V s with f s = 200 Hz. Figure 4 For different V sThe measured spectrum under [conditions]. Note that a comb spectrum appears at near-resonant frequencies, described as f p ±nf s . And the coverage band of this frequency comb increases with the increase of V s . And the frequency comb generated at f p / 2 continuously switches between two modes, mode , mode , where n is a positive integer. The tooth widths of M1 and M2 are the same, but the main peaks are 100 Hz apart. At the junction of M1 and M2, there is a short-lived mixed comb wave . Figure 5 (a) is the corresponding figure, where Figure 4 . Different dashed lines correspond to . It can be found that under this external parameter, the frequency comb switches between M1 and M2 multiple times. In addition, when there is a small detuning between f Figure 4 and f p and f 0 , due to the asymmetry of the tooth amplitudes and their attenuation rates, the number of teeth is asymmetric. In Figure 5 (a), when , the amplitudes of the teeth on the high-frequency side are larger and the number of teeth is more. The present invention extracts the amplitude changes of three teeth as shown in Figure 5 (a) and marks them with arrows (75kHz, 75.1kHz, 74.9kHz) in Figure 5 (b). The results show that when the f p / 2 component (corresponding to M1) is suppressed, the f p / 2 + f s / 2 (corresponding to M2) component increases. When the values of the two components are equal, modes M1 and M2 are superimposed.

[0053] To confirm the conditions for generating the comb and mode switching at the PD bifurcation, the present invention tunes the resonant cavity in the bifurcation state. The Duffing phenomenon shows that at a relatively large V p voltage, the frequency response will be skewed, and the multi-valuedness of the response curve will cause a jump phenomenon. When the near-resonant pump voltage V p = 10 V and the low-frequency pump voltage V s = 0, the response results near f p / 2 of the system are as shown in Figure 6 (a). When f p is from 148.8 to 155.3 kHz, the PD bifurcation occurs. As shown by the blue spectrum line in Figure 6 (b), when V s = 0, the amplitude of the f p / 2 component (δ = 0) of the response varies with f pchanges accordingly, showing a typical spring softening effect: f p starts to increase slowly from 148 kHz and jumps from –104 (noise) to –61 dBV at f p = 148.8 kHz, and then gradually decreases to the noise. The present invention also extracts the amplitude changes of the components on both sides of f p / 2. It can be seen in the present invention that these components do not respond without applying a low-frequency pumping magnetic field.

[0054] Figure 6 (c) is the frequency comb evolution diagram when V s = 200 mV. It can be found that the frequency comb switches between M1 and M2. As shown in Figure 6 (d), the amplitudes of the components δ = 0, ±0.1 change with f p . The intensity of the component (corresponding to M1) is exchanged with the intensity of the component (corresponding to M2). When V s = 400 mV, as shown in Figure 6 (e) and (f), the switching frequency of the phonon frequency comb is higher. Generally speaking, with the enhancement of the low-frequency pumping, the spring softening effect generated by the PD bifurcation effect is destroyed.

[0055] In summary, the present invention uses a magnetostrictive resonator with a single mechanical mode to generate a phonon frequency comb under the drive of a dual-pumping magnetic field. The frequency comb located at the near-resonance pump broadens stably with the enhancement of the low-frequency pumping magnetic field, while the phonon frequency comb located at half of the near-resonance pump frequency switches multiple times with the enhancement of the low-frequency pumping magnetic field. This invention not only proposes a device and method for generating a magnetically controlled phonon frequency comb, but also the mode switching operation of this frequency comb can be extended to other nonlinear devices, enriching the means of precisely controlling the frequency comb.

[0056] The above is only the preferred embodiment of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and refinements can be made, and these improvements and refinements should also be regarded as the protection scope of the present invention.​

Claims

1. A magnetically controlled phonon frequency comb, characterized in that: A magnetostrictive resonator with a single mechanical mode undergoes three-wave mixing under the drive of a dual pump magnetic field to form a comb spectrum, thereby generating a phonon frequency comb.

2. The magnetically controlled phonon frequency comb according to claim 1, characterized in that: A switchable phonon frequency comb is realized by suppressing period-doubling bifurcation, which can switch the number of half teeth at a constant comb tooth spacing.

3. The magnetically controlled phonon frequency comb according to claim 1, characterized in that: When the near-resonant pump V p When it is lower, the tooth spacing is equal to f s The frequency comb teeth cover the frequency band with the low frequency pump V s The increase is growing steadily.

4. The magnetically controlled phonon frequency comb according to claim 2, characterized in that: When the near-resonant pump V p When the double period vibration threshold of the first vibration mode is reached, due to period doubling bifurcation and three-wave mixing, with the low-frequency pump V s With the increase of , additional comb-like structures appear.

5. A device for generating a magnetically controlled phonon frequency comb according to any one of claims 1 to 4, characterized in that: It includes a magnetostrictive resonator, three induction coils used for sensing, low-frequency pumping and near-resonance pumping, an electromagnet, a function waveform generator, a phase-locked amplifier and a power amplifier; the phase-locked amplifier and the power amplifier apply a low-frequency magnetic field; the function waveform generator provides a near-resonance sinusoidal variation field.

6. The device for generating a magnetically controlled phonon frequency comb according to claim 5, characterized in that: The induction coil converts the magnetic field excited by the resonator vibration into an electrical signal, which is input into a vector network analyzer or a lock-in amplifier. The response measured by the lock-in amplifier is then post-processed in the time and frequency domains to obtain the frequency domain response of the resonator.

7. The device for generating a magnetically controlled phonon frequency comb according to claim 6, characterized in that: Apply the driving magnetic field longitudinally: ， Among them, H p represents the total driving magnetic field applied; H dc represents the longitudinal static magnetic field, applied by the electromagnet; h p The sinusoidal changing field provided by the function waveform generator; f p For near-resonant pumping V p The frequency of t represents the time. Apply a low frequency magnetic field: ， Low frequency magnetic field H s Apply through a lock-in amplifier and a power amplifier; f s Indicates low frequency pump V s The frequency of s A low-frequency sinusoidal field provided to the lock-in amplifier and power amplifier; t represents time.

8. A method for generating a magnetically controlled phonon frequency comb according to any one of claims 1 to 4, characterized in that: A magnetostrictive resonator with a single mechanical mode generates a phonon frequency comb under the drive of a dual pump magnetic field. The frequency comb located near the resonant pump steadily broadens as the low-frequency pump magnetic field increases, while the phonon frequency comb located at half the near-resonant pump frequency switches multiple times as the low-frequency pump magnetic field increases.

9. The method for generating a magnetically controlled phonon frequency comb according to claim 8, characterized in that: In the PD bifurcation state, a low-frequency pump V is applied s , a comb spectrum appears near the resonance frequency, and the frequency band covered by the frequency comb increases with V s increases with the increase of The frequency comb generated at continuously switches between the two modes.

10. The method for generating a magnetically controlled phonon frequency comb according to claim 9, characterized in that: model ,model , where n is a positive integer; under the enhancement of the low-frequency pump magnetic field, the frequency comb switches between M1 and M2.

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