Generation device and generation method of soliton micro comb

Abstract

The invention provides a soliton micro-comb generation device and method, and relates to the technical field of laser. The soliton micro-comb generation device comprises a laser, a current controller, a first temperature controller, a phase shifter and an optical micro-cavity module, the laser is used for emitting a pump beam, and the pump beam enters the optical micro-cavity module through the phase shifter; after a pump light beam enters the optical microcavity module, an optical sideband is generated based on the four-wave mixing effect, the optical microcavity module reflects part of the pump light beam into an inner cavity of the laser, the phase shifter is used for adjusting the optical path between the laser and the optical microcavity module, and a soliton micro comb is generated and output in the optical microcavity module based on a self-injection locking mechanism. According to the soliton micro-comb generation device and method provided by the embodiment of the invention, the packaging difficulty of the generation device and the requirement on the precision of the device can be reduced, a soliton micro-comb light source can be conveniently deployed outside a laboratory, and the stability of the soliton micro-comb output by the generation device is improved.

Description

Technical Field

[0001] The present invention relates to the field of laser technology, and in particular to a device and method for generating a soliton micro-comb. Background Art

[0002] In recent years, the method of generating optical frequency combs based on optical microcavities has attracted great attention. The optical frequency combs generated are called soliton microcombs.

[0003] The current mainstream scheme for obtaining soliton microcombs using the self-injection locking method is to use a packaging process that directly couples the end faces of a semiconductor laser chip with an integrated photonic chip, so that the optical phase between the semiconductor laser chip and the integrated photonic chip is in a suitable range, and the appropriate current and temperature are set for the semiconductor laser chip to generate a soliton microcomb signal. This method has very strict requirements for the feedback optical phase conditions, and the packaging difficulty is extremely high. In addition, the packaged device will still change the coupling conditions and phase between the semiconductor laser chip and the integrated photonic chip end faces due to thermal effects or mechanical stress, resulting in unstable output of the soliton microcomb signal or even failure to generate a soliton microcomb. In addition, the parameters such as the central wavelength and repetition frequency of the soliton optical comb signal generated by this scheme cannot be continuously tuned, which limits the further application of soliton microcombs. Summary of the invention

[0004] The embodiments of the present invention provide a soliton micro-comb generating device and a generating method, which can reduce the packaging difficulty of the generating device and the requirements for device precision, and improve the stability of the soliton micro-comb output by the generating device.

[0005] In a first aspect, an embodiment of the present invention provides a soliton microcomb generating device, comprising a laser, a current controller, a first temperature controller and an optical microcavity module, wherein the optical microcavity module comprises an optical microcavity and a phase shifter, and an output end of the laser is coupled to an input end of the optical microcavity module;

[0006] The laser is used to emit a pump beam, and the pump beam is incident on the optical microcavity module through a phase shifter;

[0007] The current controller is electrically connected to the laser, and is used to modulate the size and waveform of the driving current output to the laser;

[0008] The laser is connected to a first temperature controller, and the first temperature controller is used to adjust the temperature of the laser;

[0009] The pump beam is incident on the optical microcavity module to produce a four-wave mixing effect. The optical microcavity module reflects part of the pump beam into the laser to produce a self-injection locking effect. The phase shifter is used to adjust the optical path between the laser and the optical microcavity so that a soliton microcomb is generated and output in the optical microcavity.

[0010] Optionally, the soliton microcomb generating device further comprises a spot converter, which is arranged on the optical path between the laser and the optical microcavity module, and is used to improve the coupling efficiency of the pump light beam coupled into the optical microcavity module.

[0011] Optionally, the soliton micro-comb generating device further comprises a beam splitter and a photodetector, the input end of the beam splitter is coupled to the output end of the optical micro-cavity module, and the beam splitter comprises a first output end and a second output end;

[0012] The beam splitter is used to split the soliton micro-comb into a first signal and a second signal, the first signal is output from the first output end, and the second signal is output from the second output end;

[0013] The input end of the photoelectric detector is connected to the first output end, and the photoelectric detector is used to detect the intensity and frequency of the first signal.

[0014] Optionally, the soliton micro-comb generating device further comprises an isolator and a filter;

[0015] The input end of the isolator is coupled with the output end of the optical microcavity module, and the isolator is used to make the soliton microcomb propagate unidirectionally;

[0016] The input end of the filter is coupled to the output end of the isolator, and the filter is used for filtering out the pump beam in the soliton micro-comb.

[0017] In a second aspect, an embodiment of the present invention provides a method for generating a soliton micro-comb, which is applicable to a device for generating a soliton micro-comb provided in any embodiment of the present invention, and the generating method comprises:

[0018] The laser is started, and the laser outputs a pump beam;

[0019] The pump beam is coupled into the optical microcavity module after passing through the phase shifter, and the first temperature controller and the current controller are adjusted to make the optical microcavity module produce nonlinear phenomena;

[0020] Recording the driving current {I 0 , I 1 , I 2 , ...};

[0021] Adjust the drive current from Increment to adjusting the first temperature controller and the phase shifter so that the output of the optical microcavity module presents a soliton step characteristic signal;

[0022] Determine the current value corresponding to the target soliton state;

[0023] The driving current is set to the current value corresponding to the target soliton state.

[0024] Optionally, after the optical microcavity module outputs a soliton step characteristic signal, the method further comprises:

[0025] If the step characteristic signal corresponding to the target soliton state is missing, the first temperature controller is adjusted until the step characteristic signal corresponding to the target soliton state appears.

[0026] Optionally, until a step characteristic signal corresponding to the target soliton state appears, the method further includes:

[0027] Adjust the first temperature controller until the line width of the step characteristic signal corresponding to the target soliton state is the longest, and record the temperature T of the first temperature controller at this time. 0 ;

[0028] Adjust the temperature of the first temperature controller to T 0 .

[0029] Optionally, after setting the driving current to a current value corresponding to the target soliton state, the method further includes:

[0030] When the jitter of the power of the soliton state signal acquired by the photodetector exceeds a preset threshold, the current controller is adjusted to stabilize the output power of the target soliton state signal.

[0031] Optionally, after setting the driving current to a current value corresponding to the target soliton state, the method further includes:

[0032] When the level of the step signal acquired by the photodetector changes, the phase shifter is adjusted to enable the generating device to output the target soliton state signal again.

[0033] Optionally, adjust the drive current from Increment to After adjusting the first temperature controller and the phase shifter so that the output of the optical microcavity module presents a soliton step characteristic signal, the method further includes:

[0034] If the optical microcavity module cannot output the soliton step characteristic signal, the drive current is adjusted from Increment to The first temperature controller and the phase shifter are adjusted until the output of the optical microcavity module presents a soliton step characteristic signal, wherein I n For {I 0 , I 1 , I 2 , ...} except I 0 Any item other than .

[0035] A soliton microcomb generating device provided by an embodiment of the present invention introduces an independently tunable phase shifter so that the optical path between a laser and an optical microcavity is adjustable. The phase of a self-injected pump light beam can be changed by adjusting the optical path between the laser and the optical microcavity, so that the soliton state of the soliton microcomb can be accurately locked, and the stability of the output soliton state can be improved. When the generating device is affected by the external environment, the output of the soliton state of the soliton microcomb can be stabilized by adjusting the phase shifter, thereby reducing the packaging difficulty of the generating device and the requirements for device precision, and improving the stability of the soliton microcomb output by the generating device.

[0036] It should be understood that the contents described in this section are not intended to identify the key or important features of the embodiments of the present invention, nor are they intended to limit the scope of the present invention. Other features of the present invention will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0038] Figure 1 It is a structural schematic diagram of a soliton micro-comb generating device provided by an embodiment of the present invention;

[0039] Figure 2 is a schematic structural diagram of another soliton micro-comb generating device provided by an embodiment of the present invention;

[0040] Figure 3 is a relationship diagram between power and frequency offset of a soliton micro-comb provided by an embodiment of the present invention;

[0041] Figure 4 is a relationship diagram between power and frequency offset of another soliton microcomb provided by an embodiment of the present invention;

[0042] Figure 5 is a relationship diagram between power and frequency offset of another soliton micro-comb provided by an embodiment of the present invention;

[0043] Figure 6 is a schematic structural diagram of another soliton micro-comb generating device provided by an embodiment of the present invention;

[0044] Figure 7 is a schematic structural diagram of another soliton micro-comb generating device provided by an embodiment of the present invention;

[0045] Figure 8is a schematic structural diagram of another soliton micro-comb generating device provided by an embodiment of the present invention;

[0046] Fig. 9 is a schematic structural diagram of another soliton micro-comb generating device provided by an embodiment of the present invention;

[0047] Fig.10 is a schematic structural diagram of another soliton micro-comb generating device provided by an embodiment of the present invention;

[0048] Fig.11 is a flow chart of a method for generating a soliton micro-comb provided by an embodiment of the present invention;

[0049] Fig.12 It is a flow chart of another method for generating a soliton micro-comb provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0050] In order to enable those skilled in the art to better understand the present solution, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0051] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0052] Currently, the devices that use the self-injection locking method to obtain soliton micro-combs have very strict requirements on feedback phase conditions and are extremely difficult to package. The packaged devices will still cause the coupling conditions and phases of the laser chip and the integrated photonic chip end faces to change due to thermal effects or mechanical stress, resulting in unstable soliton micro-comb signal output or even the inability to generate soliton micro-combs.

[0053] In order to solve the above problems, an embodiment of the present invention provides a soliton micro-comb generating device. Figure 1is a schematic diagram of the structure of a soliton micro-comb generating device provided by an embodiment of the present invention, with reference to Figure 1 The soliton microcomb generating device includes a laser 101, a current controller 102, a first temperature controller 103 and an optical microcavity module 105, wherein the optical microcavity module 105 includes an optical microcavity 1051 and a phase shifter 104, wherein the output end of the laser 101 is coupled with the input end of the phase shifter 104, and the output end of the phase shifter 104 is coupled with the input end of the optical microcavity module 105; the laser 101 is used to emit a pump beam, and the pump beam is incident on the optical microcavity module 105 through the phase shifter 104; the current controller 102 is electrically connected to the laser 101, The current controller 102 is used to modulate the size and waveform of the driving current output to the laser 101; the laser 101 is connected to the first temperature controller 102, and the first temperature controller 102 is used to adjust the temperature of the laser 101; the pump beam is incident on the optical microcavity module to generate a four-wave mixing effect, and the optical microcavity module 105 reflects part of the pump beam into the laser 101 to generate a self-injection locking effect, and the phase shifter 104 is used to adjust the optical path between the laser 101 and the optical microcavity 1051, so that a soliton microcomb is generated and output in the optical microcavity 1051.

[0054] Optionally, the laser 101 includes but is not limited to a distributed feedback laser (DFB) or a distributed Bragg reflector (DBR), and the wavelength of the pump beam output by the laser 101 is 1550nm, 1064nm, 980nm, 785nm or 532nm. The current controller 102 uses a programmable constant current source to provide a driving current, and the current controller 102 can provide a sinusoidal current signal, a triangular current signal and a pulse current signal, and can also provide a low-noise DC signal. The phase shifter 104 includes but is not limited to a temperature controller, a piezoelectric ceramic, a plated resistance wire integrated waveguide or an optical fiber. The optical microcavity module 105 includes an optical microcavity and a coupling device, and the optical microcavity includes all optical microcavities with a whispering gallery structure, for example, an optical microcavity in the form of a discrete device prepared from an alkali metal fluoride crystal or fused quartz, and an integrated photonic chip optical microcavity prepared from silicon nitride, lithium niobate, aluminum nitride or silicon.

[0055] refer to Figure 1, after the pump beam emitted by the laser 101 passes through the phase shifter 104 and enters the optical microcavity 1051, the frequency and phase of the pump beam need to meet the phase matching conditions of four-wave mixing, and only then will the soliton microcomb be generated in the optical microcavity 1051. The frequency and power of the pump beam are affected by temperature and driving current. When the driving current of the laser 101 increases, the power of the pump beam increases accordingly. If the driving current of the laser 101 decreases, the power of the pump beam decreases accordingly. When the temperature of the laser 101 increases, the frequency of the pump beam decreases accordingly. When the temperature of the laser 101 decreases, the frequency of the pump beam increases accordingly. Therefore, to generate a soliton microcomb, it is necessary to adjust the size of the driving current output by the current controller 102 and the first temperature controller 103 so that the frequency of the pump beam matches that of the optical microcavity and meets the phase matching conditions. When the driving current and the temperature of the laser 101 are adjusted to appropriate sizes, the optical microcavity 1051 will output a soliton microcomb. At the same time, the optical microcavity 1051 will reflect part of the pump beam to the light-emitting end face of the laser 101. The pump beam reflected to the laser 101 will trigger the self-injection locking mechanism to lock the soliton state of the soliton microcomb. By adjusting the optical path between the laser 101 and the optical microcavity 1051 through the phase shifter 104, the phase of the pump beam reflected to the light-emitting end face of the laser 101 can be changed, thereby realizing the tuning of the soliton state output by the generating device. In addition, there will be slight noise in the driving current output by the current controller 102. By adjusting the phase shifter 104, the influence of the noise of the driving current on the soliton state output by the generating device can be offset, thereby making the soliton state output by the generating device more stable.

[0056] Figure 2 is a schematic diagram of the structure of another soliton micro-comb generating device provided by an embodiment of the present invention, combined with Figure 1 and Figure 2 As shown, the phase shifter 104 can be arranged on the optical path between the laser 101 and the optical microcavity 1051 , or the phase shifter 104 can be connected to the optical microcavity 1051 . Both of these arrangements can adjust the optical path between the laser 101 and the optical microcavity 1051 .

[0057] A soliton microcomb generating device provided by an embodiment of the present invention introduces an independently tunable phase shifter so that the optical path between a laser and an optical microcavity is adjustable. The phase of a self-injected pump light beam can be changed by adjusting the optical path between the laser and the optical microcavity, so that the soliton state of the soliton microcomb can be accurately locked, and the stability of the output soliton state can be improved. When the generating device is affected by the external environment, the output of the soliton state of the soliton microcomb can be stabilized by adjusting the phase shifter, thereby reducing the packaging difficulty of the generating device and the requirements for device precision, and improving the stability of the soliton microcomb output by the generating device.

[0058] Figure 3is a relationship diagram between power and frequency offset of a soliton microcomb provided by an embodiment of the present invention,

[0059] Figure 4 is a relationship diagram between power and frequency offset of another soliton microcomb provided by an embodiment of the present invention, Figure 5 is another relationship diagram between the power and frequency offset of a soliton microcomb provided by an embodiment of the present invention, combined with Figure 1 , Figure 2 , Figure 3 , Figure 4 and Figure 5 As shown, the frequency offset is used to reflect the relative size of the frequency of the soliton microcomb. Figure 3 The soliton microcomb in the quartz crystal has a complete step structure. Figure 4 The first-level step structure of the soliton microcomb is missing. Figure 5 The third-level step structure of the soliton microcomb is missing, and each step structure corresponds to a soliton state. The frequency offset of the soliton microcomb corresponds to the driving current amplitude of the laser 101. By fixing the driving current value at a position corresponding to a soliton state, the generating device can output the corresponding soliton state signal. If the step structure of the target soliton state is missing or too short, the optical path between the laser 101 and the optical microcavity module 105 can be adjusted by the phase shifter 104 to change the phase of the pump light beam reflected to the light-emitting end face of the laser 101, thereby adjusting the step structure length corresponding to the target soliton state, that is, tuning the central wavelength and repetition frequency of the soliton microcomb.

[0060] Figure 6 is a schematic diagram of the structure of another soliton micro-comb generating device provided by an embodiment of the present invention, with reference to Figure 6 The soliton micro-comb generating device also includes a spot converter 106 , which is arranged on the optical path between the laser 101 and the optical micro-cavity module 105 . The spot converter is used to improve the coupling efficiency of the pump light beam coupled into the optical micro-cavity module 105 .

[0061] refer to Figure 6 The spot converter 106 can match the laser spot of the pump beam with the spot size at the incident end of the optical microcavity module 105, thereby improving the coupling efficiency of the pump beam into the optical microcavity module 105 and reducing the loss of the pump beam. Optionally, the spot converter 106 includes a microlens, a silicon optical waveguide with a special structural design (such as an inverted cone), or a special end-face optical fiber (such as a wedge-shaped optical fiber or a coated lens optical fiber).

[0062] Figure 7 is a schematic diagram of the structure of another soliton micro-comb generating device provided by an embodiment of the present invention, with reference to Figure 7The soliton micro-comb generating device also includes a beam splitter 107 and a photodetector 108. The input end of the beam splitter 107 is coupled with the output end of the optical micro-cavity module 105. The beam splitter 107 includes a first output end and a second output end. The beam splitter 107 is used to split the soliton micro-comb into a first signal S1 and a second signal S2. The first signal S1 is output from the first output end, and the second signal S2 is output from the second output end. The input end of the photodetector 108 is connected to the first output end, and the photodetector 108 is used to detect the intensity and frequency of the first signal S1. Optionally, the photodetector 108 is connected to an acquisition card, and the acquisition card is used to store the data detected by the photodetector 108.

[0063] refer to Figure 7 , the photodetector 108 can convert the first signal S1 into an electrical signal. Exemplarily, the photodetector 108 is a photodiode, and the changes in the frequency and intensity of the first signal S1 can be converted into changes in the photodiode current. The electrical signal output by the photodetector 108 is proportional to the light intensity of the first signal S1. In the generation and locking stages of the soliton micro-comb, the different states of the soliton micro-comb can be determined by observing the photodetector 108. The first signal S1 is a detection signal, which is used to be input to the photodetector 108. The second signal S2 is the final output signal.

[0064] Optionally, the soliton micro-comb generating device further comprises an optical amplifier, the input end of the optical amplifier is coupled to the second output end, and the optical amplifier is used to amplify the second signal S2. Exemplarily, the optical amplifier comprises a semiconductor optical amplifier (SOA) or an erbium doped fiber application amplifier (EDFA).

[0065] Figure 8 is a schematic diagram of the structure of another soliton micro-comb generating device provided by an embodiment of the present invention, with reference to Figure 8 The phase shifter 104 includes a piezoelectric module 109 , which is connected to the optical microcavity module 105 . The piezoelectric module 109 is used to move the optical microcavity module 105 to adjust the optical path between the laser 101 and the optical microcavity module 105 .

[0066] refer to Figure 8 Exemplarily, the piezoelectric module 109 includes a piezoelectric ceramic sheet and a piezoelectric controller. The piezoelectric ceramic sheet is connected to the optical microcavity module 105. The piezoelectric controller controls the piezoelectric ceramic sheet to deform by applying voltage signals of different magnitudes to the piezoelectric ceramic sheet, thereby driving the optical microcavity module 105 to move, so that the distance between the optical microcavity module 105 and the laser 101 changes, thereby changing the optical path between the laser 101 and the optical microcavity module 105.

[0067] Fig. 9 is a schematic diagram of the structure of another soliton micro-comb generating device provided by an embodiment of the present invention, with reference to Fig. 9 The phase shifter 104 includes a second temperature controller 110 and a thermosensitive waveguide 111, wherein a first end of the thermosensitive waveguide 111 is coupled to an output end of the laser 101, and a second end of the thermosensitive waveguide 111 is coupled to an input end of the optical microcavity module 105; the second temperature controller 110 is connected to the thermosensitive waveguide 111, and the second temperature controller 110 is used to adjust the temperature of the thermosensitive waveguide 111 to adjust the optical path between the laser 101 and the optical microcavity module 105.

[0068] refer to Fig. 9 , the pump beam passes through the spot converter 106 and the thermosensitive waveguide 111 in sequence and is coupled into the optical microcavity module 105. The second temperature controller 110 can heat the thermosensitive waveguide 111, causing the thermosensitive waveguide 111 to undergo thermal expansion and thermorefractive refraction. The thermal expansion will cause the size of the thermosensitive waveguide 111 to change, and the thermorefractive refraction will cause the refractive index of the thermosensitive waveguide 111 to the same wavelength laser to change, thereby changing the size and refractive index of the thermosensitive waveguide 111, thereby changing the optical path of the pump beam in the thermosensitive waveguide 111, that is, changing the optical path between the laser 101 and the optical microcavity module 105. Exemplarily, the thermosensitive waveguide 111 includes an integrated waveguide plated with a resistance wire, and the second temperature controller 110 includes a voltage source, which applies a voltage to the resistance wire, and the heat generated by the resistance wire can be transferred to the integrated waveguide, thereby heating the integrated waveguide.

[0069] Optionally, the thermosensitive waveguide comprises an optical fiber. Exemplarily, the optical fiber comprises a fused-tapered optical fiber, and the material of the optical fiber is silica.

[0070] Fig.10 is a schematic diagram of the structure of another soliton micro-comb generating device provided by an embodiment of the present invention, with reference to Fig.10 , the device for generating the soliton microcomb also includes an isolator 113 and a filter 112; the input end of the isolator 113 is coupled to the output end of the optical microcavity module 105, and the isolator 113 is used to make the soliton microcomb propagate unidirectionally; the input end of the filter 112 is coupled to the output end of the optical microcavity module 105, and the filter 112 is used to filter out the pump beam in the soliton microcomb. The filter 112 is used to prevent the photodetector 108 from receiving the pump beam, thereby improving the detection accuracy of the photodetector 108. Exemplarily, the filter 112 includes but is not limited to a fiber Bragg grating, a thin film filter, or an Add-Drop structure whispering gallery optical microcavity. The isolator 113 can prevent the soliton microcomb from being reflected or scattered by subsequent optical devices and then returning to the optical microcavity module 105, thereby ensuring the unidirectional propagation of the soliton microcomb.

[0071] Optionally, the generating device further comprises a polarization-maintaining optical fiber, which is connected to an optical device in the generating device and is used to transmit an optical signal. The polarization-maintaining optical fiber can keep the polarization of the optical signal unchanged, thereby improving the coherent signal-to-noise ratio.

[0072] Based on the same inventive concept, an embodiment of the present invention provides a method for generating a soliton micro-comb, which is applicable to a device for generating a soliton micro-comb provided in any embodiment of the present invention. Fig.11 is a flow chart of a method for generating a soliton micro-comb provided by an embodiment of the present invention, with reference to Fig.11 , the generation methods include:

[0073] S101, start the laser, and the laser outputs a pump beam.

[0074] Specifically, combined Fig.10 and Fig.11 As shown, firstly, the light output direction of the laser 101 is aligned with the incident end face of the optical microcavity module 105, and then the laser is started. When the output light intensity of the optical microcavity module 105 reaches the maximum value, it means that the coupling efficiency of the pump light beam coupled into the optical microcavity module 105 is the maximum, and the laser 101 and the optical microcavity module 105 are aligned.

[0075] S102, the pump light beam is coupled into the optical microcavity module after passing through the phase shifter, and the first temperature controller and the current controller are adjusted to make the optical microcavity module produce nonlinear phenomena.

[0076] Specifically, combined Fig.10 and Fig.11 As shown, the temperature of the laser 101 is adjusted to T by adjusting the first temperature controller 103. 0 , and then the current controller 102 controls the driving current to increase monotonically from 0 at a certain step speed, and observes whether the photodetector 108 detects a new frequency. If the photodetector 108 detects a light beam with a frequency different from the pump light beam, it means that the optical microcavity module 105 has a nonlinear phenomenon. It is further understood that the soliton microcomb generation device includes a filter 112, which can filter out the pump light. Therefore, when the optical power received by the photodetector 108 is greater than 0, it can be directly determined that the optical microcavity module 105 has a nonlinear phenomenon.

[0077] S103, recording the driving current {I 0 , I 1 , I 2 , ...}.

[0078] Specifically, the driving current I when all optical microcavity modules 105 produce nonlinear phenomena is recorded, and is recorded as a collection {I 0 , I 1 , I2 , ...}.

[0079] S104, adjust the drive current from Increment to The first temperature controller and the phase shifter are adjusted so that the output of the optical microcavity module presents a soliton step characteristic signal.

[0080] Specifically, combined Fig.10 and Fig.11 As shown, since the soliton microcomb is a series of electromagnetic waves within a certain frequency range, the driving current needs to be scanned within a certain amplitude so that the generating device outputs a complete soliton microcomb. By adjusting the current controller 102, the driving current is set to the frequency F 0 、Center current I 0 , amplitude ΔI 0 A triangular wave frequency sweep current signal, such as a frequency F 0 =10Hz, amplitude ΔI 0 =10mA, the driving current value is to The first temperature controller 103 and the phase shifter 104 are simultaneously adjusted until the optical microcavity module 105 outputs a soliton step characteristic signal. At this time, the soliton step characteristic signal may have a missing or too short step structure corresponding to the target soliton state. For example, for example Figure 4 In the step structure shown in FIG. 1 , a first step structure is missing. At this time, the first temperature controller 103 is controlled to gradually lower the temperature of the laser 101, so that a first step structure can appear. Figure 5 In the step structure shown, the length of the first step structure is too short. In this case, the first temperature controller 103 is controlled to gradually increase the temperature of the laser 101, so that the first step structure can be extended.

[0081] S105. Determine the current value corresponding to the target soliton state.

[0082] Specifically, combined Fig.10 and Fig.11 As shown, illustratively, Figure 3 The frequency offset of the soliton microcomb in to The current value between them corresponds to each other, thereby determining the current value corresponding to the target soliton state.

[0083] S106, setting the driving current to a current value corresponding to the target soliton state.

[0084] Specifically, combined Fig.10 and Fig.11As shown, the driving current is set to the current value corresponding to the target soliton state, and the generating device can output the target soliton state. It can be understood that the longer the step structure is in the direction of the frequency offset, the larger the corresponding driving current range is, and the corresponding soliton state can be obtained as long as the driving current is within this range. If the frequency of the soliton state is offset during the process of outputting the target soliton state, the frequency of the output soliton state can be adjusted to the center frequency of the target soliton state by adjusting the phase shifter 104 to ensure that even if the frequency of the soliton state is offset to a certain extent, the output soliton state can be maintained in the target soliton state.

[0085] Fig.12 is a flow chart of another method for generating a soliton micro-comb provided by an embodiment of the present invention, with reference to Fig.12 , the generation methods include:

[0086] S201, start the laser, and the laser outputs a pump beam.

[0087] S202, the pump light beam is coupled into the optical microcavity module after passing through the phase shifter, and the first temperature controller and the current controller are adjusted to make the optical microcavity module produce nonlinear phenomena.

[0088] S203, recording the driving current {I 0 , I 1 , I 2 , ...}.

[0089] S204, adjust the drive current from Increment to The first temperature controller and the phase shifter are adjusted so that the output of the optical microcavity module presents a soliton step characteristic signal.

[0090] S205, if the optical microcavity module cannot output the soliton step characteristic signal, adjust the driving current from Increment to The first temperature controller and the phase shifter are adjusted until the output of the optical microcavity module presents a soliton step characteristic signal, wherein I n For {I 0 , I 1 , I 2 , ...} except I 0 Any item other than .

[0091] If the drive current is to When the optical microcavity module cannot output the soliton step characteristic signal, other driving currents that can make the optical microcavity module produce nonlinear phenomena can be selected, that is, the driving current is adjusted from Increment to I n For {I0 , I 1 , I 2 , ...} except I 0 and adjust the first temperature controller and the phase shifter again, so that the output of the optical microcavity module presents a soliton step characteristic signal.

[0092] If the optical microcavity module still cannot output the soliton step characteristic signal, it is necessary to 0 , I 1 , I 2 , ...}, and adjust the first temperature controller and the phase shifter accordingly, and repeat this process until the output of the optical microcavity module presents a soliton step characteristic signal.

[0093] S206 , if the step characteristic signal corresponding to the target soliton state is missing, adjust the first temperature controller until the step characteristic signal corresponding to the target soliton state appears.

[0094] After the optical microcavity module outputs a soliton step characteristic signal, the step characteristic signal corresponding to the target soliton state may be missing. When the step characteristic signal corresponding to the target soliton state is missing, the step characteristic signal corresponding to the target soliton state can be made to appear by adjusting the first temperature controller.

[0095] S207, adjusting the first temperature controller until the line width of the step characteristic signal corresponding to the target soliton state is the longest, and recording the temperature T of the first temperature controller at this time 0 .

[0096] There is a corresponding relationship between the frequency of the step characteristic signal and the driving current value. The longer the line width of the step characteristic signal corresponding to the target soliton state, the larger the range of the driving current value that can be output for the target soliton state. Therefore, when the line width of the step characteristic signal corresponding to the target soliton state is the longest, the accuracy requirement for the driving current value is the lowest.

[0097] S208, adjusting the temperature of the first temperature controller to T 0 .

[0098] The temperature of the first temperature controller is adjusted to T 0 , which can maximize the range of driving current values ​​of the output target soliton state and make the output target soliton state more stable.

[0099] S209, determining a current value corresponding to the target soliton state.

[0100] S210, setting the driving current to a current value corresponding to the target soliton state.

[0101] S211 . When the jitter of the power of the soliton state signal acquired by the photodetector exceeds a preset threshold, the current controller is adjusted to stabilize the output power of the target soliton state signal.

[0102] Specifically, the preset threshold is a value used to determine whether the power of the soliton state signal is stable. When the jitter of the power of the soliton state signal exceeds the preset threshold, it means that the power of the soliton state signal is unstable at this time, and the driving current may have jitter or noise. It is necessary to stabilize the driving current by adjusting the current controller to keep the power of the output soliton state signal stable.

[0103] S212. When the level of the step signal acquired by the photodetector changes, the phase shifter is adjusted to enable the generating device to output the target soliton state signal again.

[0104] Specifically, each step signal in the soliton step characteristic signal corresponds to a soliton state. When the number of step signals in the soliton step characteristic signal corresponding to the soliton state signal obtained by the photodetector changes, it indicates that the soliton state of the soliton state signal output by the generating device has changed. This may be caused by a jump in the driving current output by the current controller or a change in the external temperature. At this time, the generating device can re-output the target soliton state by adjusting the phase shifter.

[0105] The above specific implementations do not constitute a limitation on the protection scope of the present invention. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modification, equivalent substitution and improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A soliton micro-comb generating device, characterized in that: It comprises a laser, a current controller, a first temperature controller and an optical microcavity module, wherein the optical microcavity module comprises an optical microcavity and a phase shifter, and the output end of the laser is coupled with the input end of the optical microcavity module; The laser is used to emit a pump beam, and the pump beam is incident on the optical microcavity module through the phase shifter; The current controller is electrically connected to the laser, and the current controller is used to modulate the size and waveform of the driving current output to the laser; The laser is connected to the first temperature controller, and the first temperature controller is used to adjust the temperature of the laser; The pump beam is incident on the optical microcavity module to generate a four-wave mixing effect. The optical microcavity module reflects part of the pump beam into the laser to generate a self-injection locking effect. The phase shifter is used to adjust the optical path between the laser and the optical microcavity so that a soliton microcomb is generated and output in the optical microcavity.

2. The soliton micro-comb generating device according to claim 1, characterized in that: It also includes a spot converter, which is arranged on the optical path between the laser and the optical microcavity module, and is used to improve the coupling efficiency of the pump light beam coupled into the optical microcavity module.

3. The soliton micro-comb generating device according to claim 1, characterized in that: It also includes a beam splitter and a photodetector, wherein the input end of the beam splitter is coupled to the output end of the optical microcavity module, and the beam splitter includes a first output end and a second output end; The beam splitter is used to split the soliton micro-comb into a first signal and a second signal, the first signal is output from the first output end, and the second signal is output from the second output end; The input end of the photodetector is connected to the first output end, and the photodetector is used to detect the intensity and frequency of the first signal.

4. The soliton micro-comb generating device according to claim 1, characterized in that: Also includes isolators and filters; The input end of the isolator is coupled to the output end of the optical microcavity module, and the isolator is used to make the soliton microcomb propagate unidirectionally; The input end of the filter is coupled to the output end of the isolator, and the filter is used to filter out the pump light beam in the soliton micro-comb.

5. A method for generating a soliton micro-comb, characterized in that: The device for generating a soliton micro-comb according to any one of claims 1 to 4, wherein the generating method comprises: Starting a laser, wherein the laser outputs a pump beam; The pump beam is coupled into the optical microcavity module after passing through the phase shifter, and the first temperature controller and the current controller are adjusted to cause the optical microcavity module to produce nonlinear phenomena; Recording the driving current {I0, I1, I2, ...} when the optical microcavity module produces a nonlinear phenomenon; Adjust the drive current from Increment to adjusting the first temperature controller and the phase shifter so that the output of the optical microcavity module presents a soliton step characteristic signal; Determine the current value corresponding to the target soliton state; The driving current is set to a current value corresponding to the target soliton state.

6. The method for generating a soliton micro-comb according to claim 5, characterized in that: After the optical microcavity module outputs a soliton step characteristic signal, the method further includes: If the step characteristic signal corresponding to the target soliton state is missing, the first temperature controller is adjusted until the step characteristic signal corresponding to the target soliton state appears.

7. The method for generating a soliton micro-comb according to claim 6, characterized in that: After the step characteristic signal corresponding to the target soliton state appears, the method further includes: Adjusting the first temperature controller until the laser pump current range corresponding to the target soliton state is maximum, and recording the temperature T0 of the first temperature controller at this time; The temperature of the first temperature controller is adjusted to T0.

8. The method for generating a soliton micro-comb according to claim 5, characterized in that: After setting the driving current to a current value corresponding to the target soliton state, the method further includes: When the jitter of the power of the soliton state signal acquired by the photodetector exceeds a preset threshold, the current controller is adjusted to stabilize the output power of the target soliton state signal.

9. The method for generating a soliton micro-comb according to claim 5, characterized in that: After setting the driving current to a current value corresponding to the target soliton state, the method further includes: When the level of the step signal acquired by the photodetector changes, the phase shifter is adjusted to enable the generating device to output the target soliton state signal again.

10. The method for generating a soliton micro-comb according to claim 5, characterized in that: Adjust the drive current from Increment to After adjusting the first temperature controller and the phase shifter so that the output of the optical microcavity module presents a soliton step characteristic signal, the method further includes: If the optical microcavity module cannot output the soliton step characteristic signal, the driving current is adjusted from Increment to and adjusting the first temperature controller and the phase shifter until the optical microcavity module outputs the soliton step characteristic signal, wherein I n is any item in {I0, I1, I2, ...} except I0.

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