An octave light soliton generation system and method

Abstract

The embodiment of the application discloses an octave optical soliton generation system and method. The octave optical soliton generation system comprises a pump laser, an auxiliary laser, a first polarization controller, a second polarization controller, a tapered fiber and an optical microcavity; the pump laser is used for outputting pump light; the first polarization controller is used for adjusting the polarization state of the pump light in the tapered fiber; the auxiliary laser is used for outputting auxiliary light; the second polarization controller is used for adjusting the polarization state of the auxiliary light in the tapered fiber; the wavelength, power, polarization state of the pump light and auxiliary light and the distance between the tapered region and the optical microcavity are adjusted, so that the pump light generates four-wave mixing when transmitting in the optical microcavity, and an octave optical soliton is generated. The technical scheme of the embodiment of the application designs an octave soliton microcomb system by using an optical microcavity of an echo wall mode, and based on the system, an octave soliton microcomb with a bicolor dispersion wave and a 650GHz repetition frequency can be obtained.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of laser technology, in particular to a octave optical soliton generation system and method. BACKGROUND

[0002] Optical frequency comb is a spectrum composed of a series of optical spectral lines with equal frequency intervals, and each frequency of light in the frequency domain is called a "comb tooth", and the adjacent frequencies are strictly equally spaced. The supercontinuum generated by fiber nonlinear spectrum broadening can provide a octave of pulse laser coherent bandwidth, which is a key step to realize the self-reference scheme. The carrier envelope offset frequency (f ceo ) of the frequency comb can be measured by using the self-reference method. By measuring the offset frequency and the repetition frequency (f rep ), the optical frequency of all comb lines can be accurately determined by using the relationship v n =f ceo +nf rep , where n represents the respective comb line. Therefore, the optical comb can be used as a ruler for frequency measurement. Using this ruler, the optical period can be reliably and accurately calculated on the femtosecond (10 -15 s) time scale, which is necessary for realizing an optical atomic clock. In addition to optical atomic clocks and precision frequency measurement, optical combs are widely used in various emerging research fields, including attosecond pulse generation, ultraviolet and infrared (IR) spectroscopy, precision distance measurement, remote sensing, optical and microwave signal synthesis, and astronomical spectrometer calibration. These applications require higher accuracy in the control of frequency components and wideband spectral coverage in the optical comb.

[0003] At present, the octave soliton microcomb directly generated on-chip is only realized in a microring resonator, however, in order to meet the dispersion required for generating octave solitons, the size error of the sample microring width in the preparation process must be controlled within 10 nm, which puts higher requirements on the processing precision. SUMMARY

[0004] Embodiments of the present application provide a octave optical soliton generation system and method, which designs a octave soliton microcomb system by using an optical microcavity of an echo wall mode, and based on the system, a octave soliton microcomb (1013nm-2130nm) with a double dispersion wave and a 650GHz repetition frequency can be obtained. In addition, in the preparation process, the error of the microcavity diameter can be controlled to the order of microns, which reduces the requirements on the sample size preparation precision.

[0005] According to an aspect of the present application, a octave optical soliton generation system is provided, comprising a pump laser, an auxiliary laser, a first polarization controller, a second polarization controller, a tapered optical fiber and an optical microcavity.

[0006] The pump laser is configured to output pump light, the pump light being coupled into the tapered fiber from a first end of the tapered fiber;

[0007] The first polarization controller is in contact with a portion of the tapered fiber, the first polarization controller being configured to adjust a polarization state of the pump light in the tapered fiber;

[0008] The auxiliary laser is configured to output auxiliary light, the auxiliary light being coupled into the tapered fiber from a second end of the tapered fiber;

[0009] The second polarization controller is in contact with a portion of the tapered fiber, the second polarization controller being configured to adjust a polarization state of the auxiliary light in the tapered fiber;

[0010] A tapered region of the tapered fiber is coupled to the optical microcavity, the pump light and the auxiliary light being coupled into the optical microcavity from the tapered region, the optical microcavity being in an anomalous dispersion region and including at least one dispersive wave;

[0011] The wavelengths, powers, polarization states of the pump light and the auxiliary light, and a distance between the tapered region and the optical microcavity are adjusted such that the pump light undergoes four-wave mixing when propagating in the optical microcavity, generating octave light solitons.

[0012] Optionally, the apparatus further comprises a first circulator, a second circulator, a first coupler, a second coupler, a first photodetector, a second photodetector, a third photodetector, a fiber grating filter, a wavelength division multiplexer, an oscilloscope, a spectrum analyzer, and an optical spectrum analyzer;

[0013] A first end of the first circulator is connected to an output end of the first polarization controller, a second end of the first circulator is connected to the first end of the tapered fiber, a third end of the first circulator is connected to the first photodetector, and the first photodetector is connected to the oscilloscope;

[0014] The second end of the tapered fiber is connected to a first end of the first coupler, a second end of the first coupler is connected to the spectrum analyzer, a first end of the second circulator is connected to an output end of the second polarization controller, a second end of the second circulator is connected to a third end of the first coupler, the octave light solitons generated by the optical microcavity are received by the spectrum analyzer after passing through the first coupler, and the auxiliary light is transmitted to the tapered fiber after passing through the second circulator and the first coupler;

[0015] The third end of the second circulator is connected with the input end of the fiber grating filter, the output end of the fiber grating filter is connected with the input end of the wavelength division multiplexer, the output end of the wavelength division multiplexer is connected with the input end of the second coupler, the first output end of the second coupler is connected with the second photoelectric detector, the second output end of the second coupler is connected with the third photoelectric detector, the second photoelectric detector is connected with the oscilloscope, and the third photoelectric detector is connected with the spectrum analyzer.

[0016] Optionally, the system further comprises a first optical amplifier and a second optical amplifier, the first optical amplifier is configured to amplify the power of the pump light, and the second optical amplifier is configured to amplify the power of the auxiliary light.

[0017] Optionally, the first optical amplifier comprises a semiconductor optical amplifier or a fiber amplifier, and the second optical amplifier comprises a semiconductor optical amplifier or a fiber amplifier.

[0018] Optionally, the system further comprises a third coupler, a fourth coupler, a first power meter and a second power meter.

[0019] The input end of the third coupler is connected with the output end of the first polarization controller, the first output end of the third coupler is connected with the first power meter, and the second output end of the third coupler is connected with the first end of the first circulator.

[0020] The input end of the fourth coupler is connected with the output end of the second polarization controller, the first output end of the fourth coupler is connected with the second power meter, and the second output end of the fourth coupler is connected with the first end of the second circulator.

[0021] Optionally, the system further comprises a first attenuator and a second attenuator, the first attenuator is configured to control the attenuation of the pump light, and the second attenuator is configured to control the attenuation of the auxiliary light.

[0022] Optionally, the optical microcavity comprises any one of a micro-ring cavity, a micro-disk cavity, a micro-sphere cavity or a micro-column cavity.

[0023] Optionally, the cavity material of the optical microcavity comprises magnesium fluoride, barium fluoride, lithium niobate, aluminum nitride, silicon nitride or silicon carbide.

[0024] Optionally, the optical microcavity is prepared by a dry etching process.

[0025] According to another aspect of the present application, a method for generating octave optical solitons is provided, which comprises the following steps:

[0026] The pump laser outputs pump light, and the auxiliary laser outputs auxiliary light, and the pump light and the auxiliary light are coupled into the optical microcavity through the tapered region of the tapered optical fiber;

[0027] The wavelength, power, polarization state of the pump light and the auxiliary light and the distance between the cone region and the optical microcavity are adjusted so that four-wave mixing occurs when the pump light is transmitted in the optical microcavity to generate octave optical solitons.

[0028] An octave optical soliton generation system provided by an embodiment of the present invention includes a pump laser, an auxiliary laser, a first polarization controller, a second polarization controller, a tapered optical fiber, and an optical microcavity. The pump laser outputs pump light, which is coupled into the tapered optical fiber from a first end of the tapered optical fiber. The first polarization controller contacts a portion of the tapered optical fiber, and the polarization state of the pump light in the tapered optical fiber is adjusted by the polarization controller. The auxiliary laser outputs auxiliary light, which is coupled into the tapered optical fiber from a second end of the tapered optical fiber. The second polarization controller contacts a portion of the tapered optical fiber, and the polarization state of the auxiliary light in the tapered optical fiber is adjusted by the polarization controller. The tapered region of the tapered optical fiber is coupled to the optical microcavity, and the pump light and the auxiliary light are coupled into the optical microcavity from the tapered region. The optical microcavity is in an anomalous dispersion region and includes at least one dispersive wave. By adjusting the wavelength, power, and polarization state of the pump light and the auxiliary light, as well as the distance between the tapered region and the optical microcavity, four-wave mixing occurs when the pump light is transmitted in the optical microcavity, generating octave optical solitons. The technical solution of the present invention utilizes a whispering gallery mode optical microcavity to design a cross-octave soliton microcomb system. This system can produce an octave-band soliton microcomb (1013nm-2130nm) with dual-dispersive waves and a repetition rate of 650GHz. Furthermore, during the fabrication process, the microcavity diameter error can be controlled to the micron level, which reduces the requirements for sample size preparation precision.

[0029] It should be understood that the content described in this section is not intended to identify the key or important features of the embodiments of the present invention, nor is it intended to limit the scope of the present invention. Other features of the present invention will become readily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] 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.

[0031] Figure 1 A schematic structural diagram of an octave optical soliton generation system provided by an embodiment of the present invention;

[0032] Figure 2 A structural schematic diagram of an optical microcavity provided by an embodiment of the present application;

[0033] Figure 3 A schematic diagram of a result of dispersion simulation of a TE00 mode of the size microcavity by a finite element analysis method;

[0034] Figure 4 A schematic diagram of a step-shaped transmission spectrum collected by an oscilloscope;

[0035] Figure 5 A schematic diagram of a soliton microcomb spectrum across an octave collected by a spectrometer;

[0036] Figure 6 A schematic diagram of a comparison of low-frequency noise and floor noise of a chaotic state and a single soliton state optical comb measured by a frequency spectrum;

[0037] Figure 7 A structural schematic diagram of another octave optical soliton generation system provided by an embodiment of the present application;

[0038] Figure 8 A structural schematic diagram of still another octave optical soliton generation system provided by an embodiment of the present application;

[0039] Figure 9 A flow schematic diagram of an octave optical soliton generation method provided by an embodiment of the present application. DETAILED DESCRIPTION

[0040] In order to enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative efforts shall fall within the scope of protection of the present application.

[0041] It should be noted that the terms "first", "second", and the like in the specification and claims of the present application and the above-described drawings are used to distinguish similar objects, and do not necessarily indicate a specific order or a chronological sequence. It should be understood that the data thus used can be interchanged under appropriate circumstances, so that the embodiments of the present application described herein can be implemented in an order other than that illustrated or described herein. In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion, for example, a process, method, system, product or device that includes a series of steps or units does not necessarily have to be limited to those steps or units clearly listed, but can include other steps or units that are not clearly listed or inherent to the process, method, product or device.

[0042] Figure 1 This is a schematic diagram of the structure of an octave optical soliton generation system provided by an embodiment of the present invention. Figure 1 The octave optical soliton generation system includes a pump laser 11, an auxiliary laser 12, a first polarization controller 21, a second polarization controller 22, a tapered optical fiber 30 and an optical microcavity 40; the pump laser 11 is used to output pump light, and the pump light is coupled into the tapered optical fiber 30 from the first end of the tapered optical fiber 30; the first polarization controller 21 is in contact with a part of the tapered optical fiber 30, and the first polarization controller 21 is used to adjust the polarization state of the pump light in the tapered optical fiber 30; the auxiliary laser 12 is used to output auxiliary light, and the auxiliary light is coupled into the tapered optical fiber 30 from the second end of the tapered optical fiber 30; the second polarization controller 22 is in contact with a part of the tapered optical fiber 30, and the second polarization controller 22 is used to adjust the polarization state of the auxiliary light in the tapered optical fiber 30; the tapered region of the tapered optical fiber 30 ( Figure 1 The optical microcavity 40 is coupled with the pump light and the auxiliary light from the tapered region. The pump light and the auxiliary light are coupled into the optical microcavity 40 from the tapered region. The optical microcavity 40 is in the anomalous dispersion region and includes at least one dispersive wave. The wavelength, power, and polarization state of the pump light and the auxiliary light, as well as the distance between the tapered region and the optical microcavity 40 are adjusted so that four-wave mixing occurs when the pump light is transmitted in the optical microcavity, thereby generating octave-band optical solitons.

[0043] The pump laser 11 and the auxiliary laser 12 can be the same type of laser. The optical microcavity 40 is an on-chip integrated device, which can be integrated on a silicon wafer as a substrate. Optionally, the optical microcavity includes but is not limited to any one of a micro-ring core cavity, a micro-disk cavity, a micro-sphere cavity or a micro-column cavity. Optionally, the cavity material of the optical microcavity includes magnesium fluoride, barium fluoride, lithium niobate, aluminum nitride, silicon nitride or silicon carbide. Taking the micro-disk cavity as an example, Figure 2 Schematic diagram of the structure of the optical microcavity provided by the embodiment of the present invention. Figure 2 The optical microcavity 40 includes a substrate 41, a support pillar 42 located on one side of the substrate 41, and a microdisk cavity 43. The optical microcavity 40 is located in the anomalous dispersion region and includes at least one dispersive wave. For example, in one embodiment, a silicon oxide microdisk cavity with the following dimensions was used: 1.39 μm thick, 32.3° tilt angle, and 102.3 μm diameter. Figure 3 This is a schematic diagram of the dispersion simulation results of the TE00 mode of a micro-disk cavity of this size using the finite element analysis method. The TE00 mode of the sample under this structure has a small anomalous dispersion (D2>0) and has a double dispersion wave to obtain a larger spectral bandwidth under a given pump power and detuning.

[0044] It is understandable that in order to generate optical solitons with an octave frequency, it is necessary to precisely control the dispersion of the optical microcavity. int ) is defined as the following formula:

[0045]

[0046] where ω and ω pump respectively represent the frequency of the optical comb mode and the frequency of the pump mode, D1 represents the free spectral range of the optical microcavity, D2 and D3 are high order dispersion terms, and μ is the relative mode number between the optical comb mode and the pump mode. By designing the dispersion of the optical microcavity, the optical comb can be made to generate a dispersive wave (D int at ω = 0), which can broaden the spectrum of the optical comb and increase the power of the comb teeth.

[0047] The light transmitted in the tapered fiber 30 generates an evanescent field in the taper region, realizing the coupling between the optical microcavity 40 and the tapered fiber 30, and the taper region can be obtained by fiber fusion tapering. By adjusting the states of the first polarization controller 21 and the second polarization controller 22, the coupling efficiencies of the pump light and the optical microcavity 40 and the auxiliary light and the optical microcavity 40 can be adjusted, respectively, wherein the first polarization controller 21 and the second polarization controller 22 can be a three-ring or embedded polarization controller, and the embodiments of the present application are not limited thereto.

[0048] The specific octave soliton generation process is as follows:

[0049] The powers of the pump laser and the auxiliary laser are adjusted, so that the pump light and the auxiliary light are operated at low power, and the laser frequency is scanned at a speed of 245 MHz / ms;

[0050] The center wavelength of the pump laser is adjusted, and the mode generating the octave optical comb is found as the pump mode (TE00). In this embodiment, the pump mode corresponds to a wavelength of 1543.7 nm;

[0051] The center wavelength of the auxiliary laser is adjusted, and the TM00 mode is found as the auxiliary mode. In this embodiment, the TM00 mode has the best effect of compensating for the power jump when a soliton is generated in the cavity, and the corresponding wavelength is 1561.6 nm;

[0052] The polarizations of the pump light and the auxiliary light and the coupling between the optical microcavity and the taper region are continuously adjusted until the pump mode and the auxiliary mode are in the critical coupling state, and the critical coupling state refers to the state that the lowest point of the transmission peak is 0 by adjusting the coupling position of the fiber and the microcavity and the polarization state of the pump light and the auxiliary light;

[0053] The powers of the pump light and the auxiliary light are increased;

[0054] The frequency scanning of the auxiliary laser is turned off, the wavelength of the auxiliary laser is adjusted to the blue detuning of the auxiliary mode, the wavelength of the auxiliary light is gradually increased until the step-shaped transmission spectrum appears on the oscilloscope, and if it cannot appear, the power of the auxiliary light is further increased;

[0055] The frequency scanning of the pump laser is closed, the pump light is at the blue detuning of the pump mode, the wavelength of the pump light is slowly adjusted to the step, and then the power of the pump light is further increased until a octave soliton micro comb is generated.

[0056] wherein, Figure 4 It is a schematic diagram of the step-shaped transmission spectrum collected by an oscilloscope, and the stepwise decrease of the comb tooth power indicates the generation of solitons. Figure 5 It is a schematic diagram of the spectrum of a cross-octave soliton micro comb collected by a spectrum analyzer, and the inset is a spectrum diagram of a short-wave dispersion wave amplification, and the envelope curve is a sech 2 Fitting curve. Figure 6 It is a schematic diagram of the comparison of low-frequency noise and noise floor of the chaotic state and single soliton state optical comb measured by a spectrum analyzer, and the noise and noise floor of the single soliton state are equivalent, while the chaotic state has a significant protrusion in 0-0.5GHz.

[0057] The technical scheme of the embodiment of the present application comprises: outputting pump light by a pump laser, coupling the pump light into a tapered optical fiber from a first end of the tapered optical fiber; contacting a first polarization controller with a part of the tapered optical fiber, and adjusting the polarization state of the pump light in the tapered optical fiber through the polarization controller; outputting auxiliary light by an auxiliary laser, coupling the auxiliary light into the tapered optical fiber from a second end of the tapered optical fiber; contacting a second polarization controller with a part of the tapered optical fiber, and adjusting the polarization state of the auxiliary light in the tapered optical fiber through the polarization controller; coupling a tapered region of the tapered optical fiber with an optical microcavity, coupling the pump light and the auxiliary light into the optical microcavity from the tapered region, and the optical microcavity is in an anomalous dispersion region and comprises at least one dispersion wave; adjusting the wavelength, power, polarization state of the pump light and the auxiliary light, and the distance between the tapered region and the optical microcavity, so that four-wave mixing occurs when the pump light is transmitted in the optical microcavity, and a octave optical soliton is generated. The technical scheme of the embodiment of the present application designs a cross-octave soliton micro comb system by using an optical microcavity of an echo wall mode, and based on the system, a cross-octave soliton micro comb (1013nm-2130nm) with double dispersion waves and a 650GHz repetition frequency can be obtained. In addition, the error of the microcavity diameter is controlled in the order of microns during preparation, which reduces the requirement for the preparation precision of the sample size.

[0058] Figure 7 It is a structural schematic diagram of another octave optical soliton generation system provided by the embodiment of the present application. Figure 7Optionally, the octave light soliton generation system further comprises a first circulator 51, a second circulator 52, a first coupler 61, a second coupler 62, a first photodetector 71, a second photodetector 72, a third photodetector 73, a fiber grating filter 80, a wavelength division multiplexer 90, an oscilloscope 100, a spectrum analyzer 101, and a spectrometer 102; the first end of the first circulator 51 is connected with the output end of the first polarization controller 21, the second end of the first circulator 51 is connected with the first end of the tapered fiber 30, the third end of the first circulator 52 is connected with the first photodetector 71, and the first photodetector 71 is connected with the oscilloscope 100; the second end of the tapered fiber 30 is connected with the first end of the first coupler 61, the second end of the first coupler 62 is connected with the spectrometer 102, the first end of the second circulator 52 is connected with the output end of the second polarization controller 22, the second end of the second circulator 52 is connected with the third end of the first coupler 61, the octave light soliton generated by the optical microcavity 40 is received by the spectrometer 102 after passing through the first coupler 61, and the auxiliary light is transmitted to the tapered fiber 30 after passing through the second circulator 52 and the first coupler 61; the third end of the second circulator 52 is connected with the input end of the fiber grating filter 80, the output end of the fiber grating filter 80 is connected with the input end of the wavelength division multiplexer 90, the output end of the wavelength division multiplexer 90 is connected with the input end of the second coupler 62, the first output end of the second coupler 62 is connected with the second photodetector 72, the second output end of the second coupler 62 is connected with the third photodetector 73, the second photodetector 72 is connected with the oscilloscope 100, and the third photodetector 73 is connected with the spectrum analyzer 101.

[0059] It can be understood that, in order to verify whether the octave light soliton generation system provided by the embodiment of the present application generates octave light solitons, tests need to be carried out, and whether octave light solitons are generated is determined by observing the time domain waveform of the oscilloscope 100, the spectrum of the spectrum analyzer 101, and the spectrum measured by the spectrometer 102.

[0060] Figure 8 A structure schematic diagram of still another octave light soliton generation system provided by the embodiment of the present application is shown in FIG. 6. Figure 8 Optionally, the octave light soliton generation system further comprises a first optical amplifier 13 and a second optical amplifier 14, the first optical amplifier 13 is used for amplifying the power of the pump light, and the second optical amplifier 14 is used for amplifying the power of the auxiliary light.

[0061] In practice, the power of the pump light output by the pump laser 11 and the power of the auxiliary light output by the auxiliary laser 12 can be small and cannot reach the threshold power for exciting the octave optical soliton, and therefore, a corresponding optical amplifier can be arranged to amplify the power of the pump light and the auxiliary light to be above the threshold power. Optionally, the first optical amplifier 13 comprises a semiconductor optical amplifier or a fiber amplifier, and the second optical amplifier 14 comprises a semiconductor optical amplifier or a fiber amplifier, which can be selected according to actual conditions in practice, and the embodiments of the present application do not make any limitation in this regard.

[0062] With reference to the foregoing description of the octave optical soliton generation system, Figure 8 Optionally, the octave optical soliton generation system further comprises a third coupler 63, a fourth coupler 64, a first power meter 65 and a second power meter 66. The input end of the third coupler 63 is connected with the output end of the first polarization controller 21, the first output end of the third coupler 63 is connected with the first power meter 65, and the second output end of the third coupler 63 is connected with the first end of the first circulator 51. The input end of the fourth coupler 64 is connected with the output end of the second polarization controller 22, the first output end of the fourth coupler 64 is connected with the second power meter 66, and the second output end of the fourth coupler 64 is connected with the first end of the second circulator 52. The first power meter 65 and the second power meter 66 are respectively used to monitor the power of the pump light and the auxiliary light.

[0063] Optionally, the octave optical soliton generation system further comprises a first attenuator 15 and a second attenuator 16. The first attenuator 15 is used to control the attenuation of the pump light, and the second attenuator 16 is used to control the attenuation of the auxiliary light.

[0064] Optionally, the optical microcavity is prepared by a dry etching process. The machining size precision of the optical microcavity required by the embodiments of the present application only needs to reach the order of microns, the dry etching process has strong repeatability, and the size of the optical microcavity is controllable.

[0065] Figure 9 A flowchart of an octave optical soliton generation method provided by the embodiments of the present application is shown in the figure. The octave optical soliton generation method outputs octave optical solitons by using any one of the octave optical soliton generation systems provided by the above embodiments, with reference to the foregoing description of the octave optical soliton generation system, Figure 9 The octave optical soliton generation method comprises the following steps:

[0066] S110, the pump laser outputs pump light, and the auxiliary laser outputs auxiliary light. The pump light and the auxiliary light are coupled into the optical microcavity through the taper region of the tapered fiber.

[0067] S120, the wavelength, power, polarization state of the pump light and the auxiliary light, and the distance between the taper region and the optical microcavity are adjusted, so that the pump light generates four-wave mixing when transmitting in the optical microcavity, and the octave optical soliton is generated.

[0068] Wherein, the octave soliton generation process provided by the embodiment of the application is as follows:

[0069] The power of the pump laser and the auxiliary laser is adjusted, so that the pump light and the auxiliary light run at low power, and the laser frequency is scanned at a speed of 245MHz / ms;

[0070] The center wavelength of the pump laser is adjusted, and a mode generating an octave comb is found as a pump mode (TE00), and in the embodiment, the pump mode corresponds to a wavelength of 1543.7nm;

[0071] The center wavelength of the auxiliary laser is adjusted, and a TM00 mode is found as an auxiliary mode, and in the embodiment, the TM00 mode has the best effect of compensating for the power jump when a soliton is generated in the cavity, and the corresponding wavelength is 1561.6nm;

[0072] The polarization of the pump light and the auxiliary light and the coupling between the optical microcavity and the taper region are continuously adjusted, until the pump mode and the auxiliary mode are in a proper coupling state, and the proper coupling state refers to a state in which the coupling position of the fiber and the microcavity and the polarization state of the pump light and the auxiliary light are adjusted, so that the lowest point of the transmission peak is 0;

[0073] The power of the pump light and the auxiliary light is increased;

[0074] The frequency scanning of the auxiliary laser is turned off, the wavelength of the auxiliary laser is adjusted to the blue detuning of the auxiliary mode, the wavelength of the auxiliary light is gradually increased until a step-shaped transmission spectrum appears on the oscilloscope, and if it cannot appear, the power of the auxiliary light is further increased;

[0075] The frequency scanning of the pump laser is turned off, the pump light is at the blue detuning of the pump mode, the wavelength of the pump light is slowly adjusted to the step, and then the power of the pump light is further increased until an octave soliton microcomb is generated.

[0076] The above specific embodiments do not constitute a limitation on the protection scope of the application. Those skilled in the art should understand that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modification, equivalent replacement and improvement made within the spirit and principles of the application should be included in the protection scope of the application.

Claims

1. An octave optical soliton generation system, characterized in that: The invention comprises a pump laser, an auxiliary laser, a first polarization controller, a second polarization controller, a tapered optical fiber and an optical microcavity; The pump laser is used to output pump light, and the pump light is coupled into the tapered optical fiber from the first end of the tapered optical fiber; The first polarization controller is in contact with a partial area of ​​the tapered optical fiber, and the first polarization controller is used to adjust the polarization state of the pump light in the tapered optical fiber; The auxiliary laser is used to output auxiliary light, and the auxiliary light is coupled into the tapered optical fiber from the second end of the tapered optical fiber; The second polarization controller is in contact with a partial area of ​​the tapered optical fiber, and the second polarization controller is used to adjust the polarization state of the auxiliary light in the tapered optical fiber; The tapered region of the tapered optical fiber is coupled to the optical microcavity, the pump light and the auxiliary light are coupled into the optical microcavity from the tapered region, and the optical microcavity is in the anomalous dispersion region and includes a bichromatic dispersion wave; The wavelength, power, and polarization state of the pump light and the auxiliary light, as well as the distance between the tapered region and the optical microcavity, are adjusted so that four-wave mixing occurs when the pump light is transmitted in the optical microcavity, generating octave-band optical solitons. During the preparation of the optical microcavity, the error in the microcavity diameter is controlled to be on the micron level, and the wavelength range of the octave-band optical solitons is 1013 nm-2130 nm.

2. The octave optical soliton generation system according to claim 1, characterized in that: It also includes a first circulator, a second circulator, a first coupler, a second coupler, a first photodetector, a second photodetector, a third photodetector, a fiber grating filter, a wavelength division multiplexer, an oscilloscope, a spectrometer, and a spectrometer; The first end of the first circulator is connected to the output end of the first polarization controller, the second end of the first circulator is connected to the first end of the tapered optical fiber, the third end of the first circulator is connected to the first photodetector, and the first photodetector is connected to the oscilloscope; The second end of the tapered optical fiber is connected to the first end of the first coupler, the second end of the first coupler is connected to the spectrometer, the first end of the second circulator is connected to the output end of the second polarization controller, and the second end of the second circulator is connected to the third end of the first coupler. The octave optical soliton generated by the optical microcavity is received by the spectrometer after passing through the first coupler, and the auxiliary light is transmitted to the tapered optical fiber after passing through the second circulator and the first coupler. The third end of the second circulator is connected to the input end of the fiber Bragg grating filter, the output end of the fiber Bragg grating filter is connected to the input end of the wavelength division multiplexer, the output end of the wavelength division multiplexer is connected to the input end of the second coupler, the first output end of the second coupler is connected to the second photodetector, the second output end of the second coupler is connected to the third photodetector, the second photodetector is connected to the oscilloscope, and the third photodetector is connected to the spectrometer.

3. The octave optical soliton generation system according to claim 1, characterized in that: The system further includes a first optical amplifier and a second optical amplifier. The first optical amplifier is used to amplify the power of the pump light, and the second optical amplifier is used to amplify the power of the auxiliary light.

4. The octave optical soliton generation system according to claim 3, characterized in that: The first optical amplifier includes a semiconductor optical amplifier or a fiber amplifier, and the second optical amplifier includes a semiconductor optical amplifier or a fiber amplifier.

5. The octave optical soliton generation system according to claim 2, characterized in that: Also included is a third coupler, a fourth coupler, a first power meter, and a second power meter; The input end of the third coupler is connected to the output end of the first polarization controller, the first output end of the third coupler is connected to the first power meter, and the second output end of the third coupler is connected to the first end of the first circulator; The input end of the fourth coupler is connected to the output end of the second polarization controller, the first output end of the fourth coupler is connected to the second power meter, and the second output end of the fourth coupler is connected to the first end of the second circulator.

6. The octave optical soliton generation system according to claim 1, characterized in that: The system further comprises a first attenuator and a second attenuator, wherein the first attenuator is used to control the attenuation of the pump light, and the second attenuator is used to control the attenuation of the auxiliary light.

7. The octave optical soliton generation system according to claim 1, characterized in that: The optical microcavity includes any one of a microring core cavity, a microdisk cavity, a microsphere cavity or a microcolumn cavity.

8. The octave optical soliton generation system according to claim 1, characterized in that: The cavity material of the optical microcavity includes magnesium fluoride, barium fluoride, lithium niobate, aluminum nitride, silicon nitride or silicon carbide.

9. The octave optical soliton generation system according to claim 1, characterized in that: The optical microcavity is prepared by using a dry etching process.

10. A method for generating octave optical solitons, characterized in that: The octave optical soliton generation system according to any one of claims 1 to 9 is used to output octave optical solitons, comprising: The pump laser outputs pump light, and the auxiliary laser outputs auxiliary light, and the pump light and the auxiliary light are coupled into the optical microcavity through the tapered region of the tapered optical fiber; The wavelength, power, polarization state of the pump light and the auxiliary light and the distance between the cone region and the optical microcavity are adjusted so that four-wave mixing occurs when the pump light is transmitted in the optical microcavity to generate octave optical solitons.

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