A deterministic single soliton microcavity optical frequency comb generation device and method

Abstract

The application relates to a deterministic single-soliton microcavity optical frequency comb generating device and method, which are used for solving the problem that the prior art cannot generate a single-soliton microcavity optical frequency comb deterministically. The system supports slow tuning single-soliton microcavity optical frequency comb generation and can generate a single-soliton microcavity optical frequency comb with a probability of 100%, thereby providing technical support for future commercial small-sized microcavity single-soliton sources. The application relates to a deterministic single-soliton microcavity optical frequency comb generating device, which comprises a narrow-line-width laser, an optical amplifier, an optical circulator, a polarization controller, a micro-ring resonant cavity, a spectrometer, an oscilloscope and a frequency spectrometer; the narrow-line-width laser is sequentially connected with the optical amplifier, the optical circulator, the polarization controller and the micro-ring resonant cavity; the spectrometer, the oscilloscope and the frequency spectrometer are connected with the micro-ring resonant cavity respectively. The device and the use method thereof can generate a single-soliton microcavity optical frequency comb with a probability of 100% and support slow tuning, and have high generation efficiency.

Description

TECHNICAL FIELD

[0001] The present application relates to an optical frequency comb generation system, in particular to a deterministic single soliton microcavity optical frequency comb generation device and method. BACKGROUND

[0002] Single soliton microcavity optical frequency comb plays an important role in many fields, such as parallel large-capacity optical communication, quantum optics, high-speed precision ranging, precision spectrum measurement, frequency synthesis and other fields. At present, microcavity single soliton optical comb is usually generated by fast frequency sweeping, power-kicking, phase modulation, injection locking, double-color laser pumping, and single soliton microcavity optical frequency comb has also been realized in various microcavity resonators, such as silicon nitride microcavity, aluminum nitride microcavity, and high refractive index difference doped glass microcavity. Limited by the strong thermal light effect in the microcavity, the above-mentioned microcavity single soliton optical comb generation method has a high requirement on the tuning speed, and requires professional personnel to realize the generation of single soliton, and cannot make the microcavity single soliton completely deterministic, and the completely deterministic generation of microcavity single soliton is still a problem.

[0003] At the same time, the excitation of single soliton microcavity optical frequency comb usually needs to go through a complex evolution process, which increases the complexity of experiment and debugging, so that the single soliton cannot be spontaneously and deterministically generated. SUMMARY

[0004] In order to solve the technical problem that the prior art cannot deterministically generate single soliton microcavity optical frequency comb, the present application provides a deterministic single soliton microcavity optical frequency comb generation device and method. The device supports the generation of slow-tuning single soliton microcavity optical frequency comb, and can generate single soliton microcavity optical frequency comb with 100% probability, providing technical support for future commercial small-sized single soliton microcavity optical frequency comb sources.

[0005] The present application optimizes the waveguide structure of the microcavity, realizes the frequency shift of the local resonant mode based on the different mode coupling effect in the microcavity, and enhances the local dispersion. Under the action of the local strong dispersion, the single soliton microcavity optical frequency comb can be completely deterministically generated, and the single soliton microcavity optical frequency comb can be directly excited from the Turing mode, and the slow-tuning single soliton microcavity optical frequency comb can be generated, which provides a new technical scheme for future high-efficiency integrated optical comb, and lays a foundation for future development of on-chip optical comb applications.

[0006] In order to achieve the above-mentioned purpose, the technical scheme of the present application is as follows:

[0007] A deterministic single soliton microcavity optical frequency comb generation device, characterized in that it comprises a spectrometer, an oscilloscope and a frequency spectrometer, and a narrow linewidth laser, an optical amplifier, an optical circulator, a polarization controller and a microcavity resonator connected in sequence.

[0008] The optical amplifier is used for amplifying the power of the output laser of the narrow linewidth laser to reach the power threshold required by the single soliton microcavity optical frequency comb; the optical circulator is used for ensuring the unidirectional transmission of the laser for power amplification; the polarization controller is used for adjusting the polarization mode of the laser output by the optical circulator, so that the polarization mode of the laser is the same as the polarization mode generated by the single soliton microcavity optical frequency comb to be generated; and the micro-ring resonant cavity is used for generating the single soliton optical frequency comb.

[0009] The optical spectrum analyzer, the oscilloscope and the frequency spectrum analyzer are connected with the micro-ring resonant cavity.

[0010] Further, the narrow linewidth laser is a pump light source with continuous tunable function or with piezoelectric tuning wavelength function.

[0011] Further, the optical amplifier is a semiconductor type or a fiber type amplifier.

[0012] The optical amplifier is specifically an erbium-doped fiber amplifier.

[0013] Further, the optical circulator is a fiber type circulator.

[0014] Further, the micro-ring resonant cavity is an arbitrary semiconductor type micro-ring resonant cavity.

[0015] A deterministic single soliton microcavity optical frequency comb generation method, which is characterized by comprising the following steps:

[0016] Step 1) measuring the dispersion inside the micro-ring resonant cavity to find a region with locally enhanced dispersion;

[0017] Step 2) setting the working wavelength of the pump light source so that the pump light source incident into the micro-ring resonant cavity releases optical information near the region with locally enhanced dispersion;

[0018] Step 3) setting the output power of the optical amplifier and adjusting the polarization state of the polarization controller, so that the polarization mode of the optical information incident into the micro-ring resonant cavity is the same as the polarization mode generated by the single soliton microcavity optical frequency comb to be generated;

[0019] Step 4) setting the sweep speed of the pump light source to find a descending power step, and after finding the descending power step, tuning the sweep range of the pump light source in real time, and keeping the wavelength of the pump light source on the power step;

[0020] Step 5) fine tuning the wavelength of the pump light source, when the oscilloscope monitors the generation of the single soliton microcavity optical frequency comb, and the optical spectrum analyzer displays the characteristic spectrum of the single soliton microcavity optical frequency comb, and the frequency spectrum analyzer displays a spectrum characteristic diagram without noise characteristics, the single soliton microcavity optical frequency comb is generated.

[0021] Further, in step 2), the working wavelength of the pump light source is set to 1556 nm.

[0022] Further, in step 3), the output power of the optical amplifier is set to 2.3 W.

[0023] Further, in step 4), the sweep speed of the pump light source is set to 1 nm / s.

[0024] Compared with the prior art, the application has the following beneficial effects:

[0025] 1, the application and the generation of the single soliton microcavity optical frequency comb are based on the technical scheme of fast sweep, therefore, the application can be compatible with the current single soliton microcavity optical frequency comb generation scheme, can realize strong local dispersion generation through optimization of the microcavity structure, and has great flexibility.

[0026] 2, the device and the use method thereof can realize 100% generation of the single soliton microcavity optical frequency comb, and support slow tuning, and have high generation efficiency.

[0027] 3, the method provided by the application, the optical comb in the microcavity does not need to evolve into the single soliton microcavity optical frequency comb through a complex process, and the single soliton can be excited only through a simple Turing mode, so that the single soliton microcavity optical frequency comb is convenient to control.

[0028] 4, in the application, when the single soliton microcavity optical frequency comb is generated, the power in the microcavity does not change significantly, and the thermal-optic effect in the micro-ring resonant cavity can be overcome. BRIEF DESCRIPTION OF DRAWINGS

[0029] Figure 1 It is a schematic diagram of the system structure of the application;

[0030] Figure 2 It is a dispersion diagram of the micro-ring resonant cavity in the embodiment of the application;

[0031] Figure 3 It is a power diagram of the micro-ring resonant cavity in the embodiment of the application;

[0032] Figure 4 It is a characteristic spectrum diagram of the single soliton microcavity optical frequency comb in the embodiment of the application;

[0033] Figure 5 It is a frequency spectrum characteristic diagram of the single soliton microcavity optical frequency comb in the embodiment of the application.

[0034] Wherein, the reference signs are as follows:

[0035] 1-narrow linewidth laser, 2-optical amplifier, 3-optical circulator, 4-polarization controller, 5-micro-ring resonant cavity, 6-optical spectrum instrument, 7-oscilloscope, 8-spectrum instrument. DETAILED DESCRIPTION

[0036] The application will be further described in conjunction with the drawings and specific embodiments.

[0037] Referring to Figure 1 A deterministic single soliton microcavity optical frequency comb generating device, comprising a narrow linewidth laser 1, an optical amplifier 2, an optical circulator 3, a polarization controller 4, a micro ring resonant cavity 5, a spectrometer 6, an oscilloscope 7, and a frequency spectrometer 8 connected in sequence by a single mode optical fiber.

[0038] The narrow linewidth laser 1 is connected in sequence by the optical amplifier 2, the optical circulator 3, the polarization controller 4, and the micro ring resonant cavity 5.

[0039] The micro ring resonant cavity 5 is directly connected with the spectrometer 6, the oscilloscope 7, and the frequency spectrometer 8, respectively.

[0040] In the device, the narrow linewidth laser 1 uses a tunable narrow linewidth laser to provide a seed source for the optical amplifier 2. Specifically, a pump light source with continuous tunable function is used as a signal light source, with a line width of 100 kHz and an output wavelength of 1556 nm, which can be controlled through an instrument interface. In other embodiments, a laser with piezoelectric tuning function can also be selected.

[0041] The optical amplifier 2 specifically uses an erbium-doped fiber amplifier. The erbium-doped fiber amplifier amplifies the optical signal output by the narrow linewidth laser 1, so that the power of the optical signal can meet the power threshold condition required for the generation of a single soliton microcavity optical frequency comb. The power amplified optical signal enters the optical circulator 3, the polarization controller 4, and the micro ring resonant cavity 5 in sequence.

[0042] The polarization controller 4 and the optical circulator 3 are high-power optical devices that can withstand 10 W.

[0043] The optical circulator 3 is a fiber type circulator, which is used to ensure that the power amplified optical signal is transmitted in one direction, avoiding its influence on the working state of the narrow linewidth laser 1 and the optical amplifier 2. The circulator is used to protect the experimental optical system and avoid damage to the optical amplifier and the laser by reflected light. In other embodiments, an isolator that can withstand high power can also be used.

[0044] The polarization controller 4 is used to adjust the polarization state of the power amplified optical signal incident on the micro ring resonant cavity 5, to ensure that the polarization state mode of the optical information emitted by the pump light source incident on the micro ring resonant cavity 5 is the same as that of the single soliton microcavity optical frequency comb.

[0045] The micro ring resonant cavity 5 generates a single soliton optical frequency comb under the control of the optical signal output by the polarization controller 4.

[0046] The local dispersion of the micro-ring resonant cavity 5 is greatly enhanced, which can enhance the local negative dispersion or adjust the positive dispersion to be negative dispersion, and a semiconductor micro-cavity or an echo wall mode micro-cavity can be selected. Specifically, the micro-ring resonant cavity 5 has a specific grating or defect structure, which can assist in adjusting the local dispersion of the micro-ring resonant cavity 5 and enhancing the local dispersion. Through the enhanced local dispersion condition, the evolution process of the optical frequency comb in the micro-ring resonant cavity 5 is affected. The micro-ring resonant cavity 5 is any semiconductor micro-ring resonant cavity, wherein the micro-ring resonant cavity 5 can be tuned through thermal tuning or piezoelectric tuning. In the embodiment, a high refractive index difference doped glass micro-ring resonant cavity of up and down channel type is used, and the micro-ring resonant cavity is packaged with a thermistor, a temperature sensor and a temperature regulator in a metal shell.

[0047] The optical spectrum analyzer 6, the oscilloscope 7 and the spectrum analyzer 8 are used to monitor the single soliton micro-cavity optical frequency comb generation and monitor the spectral characteristics thereof; wherein the optical spectrum analyzer 6 is used to monitor the characteristic spectrum of the single soliton micro-cavity optical frequency comb, the oscilloscope 7 is used to monitor whether the single soliton micro-cavity optical frequency comb is generated, and the spectrum analyzer 8 is used to monitor whether the characteristic spectrum has power oscillation and noise.

[0048] The functions of the above components in the system of the present application are as follows:

[0049] The use process of the single soliton micro-cavity optical frequency comb generation device is as follows:

[0050] 1) The dispersion inside the micro-ring resonant cavity 5 is measured to find the region with enhanced local dispersion, as shown in the following figure: Figure 2

[0051] 2) All instruments and equipment are turned on, the working wavelength of the pump light source is set to 1556 nm, and the pump light source is set to release optical information near the region with enhanced local dispersion;

[0052] 3) The output power of the optical amplifier 3 is set to 2.3 W, the polarization state of the polarization controller 4 is adjusted, and the polarization state of the optical information emitted by the pump light source is made to be the same as the polarization state of the single soliton micro-cavity optical frequency comb;

[0053] 4) The sweep speed of the pump light source is set to 1 nm / s, and the power step of the power drop of the output light field is found, as shown in the following figure: Figure 3 After the power step is found, the sweep range of the pump light source is tuned in real time, and the wavelength of the pump light source is stopped on the power step;

[0054] 5) The wavelength of the pump light source is finely adjusted, and when the optical spectrum analyzer 6 shows the characteristic spectrum of the single soliton micro-cavity optical frequency comb as shown in the following figure: Figure 4 When the oscilloscope 7 monitors that the single soliton micro-cavity optical frequency comb is generated, and when the image displayed by the spectrum analyzer 8 has no noise as shown in the following figure: Figure 5 , the single soliton micro-cavity optical frequency comb is generated. ​

[0055] In summary, the present application provides a single soliton microcavity optical frequency comb generation method and device. When a single soliton is generated, the power in the microcavity does not change significantly, which can overcome the thermal-optic effect in the microcavity. Moreover, the present application has the advantages of simple operation and can realize the deterministic generation of a single soliton microcavity optical frequency comb, which provides strong support for the future development of on-chip optical comb applications.

Claims

1. A deterministic single soliton microcavity optical frequency comb generation method, characterized in that, The single soliton microcavity optical frequency comb is generated by a deterministic single soliton microcavity optical frequency comb generation device, wherein: The deterministic single soliton microcavity optical frequency comb generation device comprises a spectrum analyzer (6), an oscilloscope (7) and a frequency spectrum analyzer (8), and a narrow linewidth laser (1), an optical amplifier (2), an optical circulator (3), a polarization controller (4) and a micro ring resonator (5) connected in sequence; The optical amplifier (2) is used to amplify the power of the output laser of the narrow linewidth laser (1) to reach the power threshold required for the generation of the single soliton microcavity optical frequency comb; the optical circulator (3) is used to ensure the unidirectional transmission of the power-amplified laser; the polarization controller (4) is used to adjust the polarization state mode of the laser output by the optical circulator (3) so that the polarization state mode of the laser is the same as that of the single soliton microcavity optical frequency comb to be generated; and the micro ring resonator (5) is used to generate the single soliton optical frequency comb. The spectrum analyzer (6), the oscilloscope (7) and the frequency spectrum analyzer (8) are connected with the micro ring resonator (5). The deterministic single soliton microcavity optical frequency comb generation device generates a single soliton microcavity optical frequency comb, comprising the following steps: Step 1) measuring the dispersion inside the micro ring resonator (5) to find the region with locally enhanced dispersion; Step 2) setting the working wavelength of the pump source so that the optical information incident into the micro ring resonator (5) is released near the region with locally enhanced dispersion; Step 3) setting the output power of the optical amplifier (2) and adjusting the polarization state of the polarization controller (4) so that the polarization state mode of the optical information incident into the micro ring resonator (5) is the same as that of the single soliton microcavity optical frequency comb to be generated; and the single soliton microcavity optical frequency comb is excited through the Turing mode; Step 4) setting the sweep speed of the pump source so that the falling power step is found, and after the falling power step is found, the sweep range of the pump source is tuned in real time, and the wavelength of the pump source is always stopped on the power step; Step 5) fine-tuning the wavelength of the pump source, and when the single soliton microcavity optical frequency comb is generated and the characteristic spectrum of the single soliton microcavity optical frequency comb is displayed by the oscilloscope (7) and the spectrum analyzer (6), and the frequency spectrum characteristic diagram displayed by the frequency spectrum analyzer (8) has no noise characteristics, the single soliton microcavity optical frequency comb is generated.

2. The deterministic single soliton microcavity optical frequency comb generation method according to claim 1, wherein in step 2), the working wavelength of the pump source is set to 1556 nm.

3. The deterministic single soliton microcavity optical frequency comb generation method according to claim 2, wherein in step 3), the output power of the optical amplifier (2) is set to 2.3 W.

4. The deterministic single soliton microcavity optical frequency comb generation method according to claim 3, wherein in step 4), the sweep speed of the pump source is set to 1 nm / s. The narrow linewidth laser (1) is a pump source with continuous tunable function or piezoelectric tuning wavelength function.

6. The deterministic single soliton microcavity optical frequency comb generation method according to claim 5, wherein the optical amplifier (2) is a semiconductor type or fiber type amplifier. ​ 5. The deterministic single soliton microcavity optical frequency comb generation method of claim 4, wherein: ​ ​ ​ 7. The deterministic single soliton microcavity optical frequency comb generation method according to claim 5, characterized in that: The optical amplifier (2) is an erbium-doped fiber type amplifier.

8. The deterministic single soliton microcavity optical frequency comb generation method according to claim 6, characterized in that: The optical circulator (3) is a fiber type circulator.

9. The deterministic single soliton microcavity optical frequency comb generation method according to claim 8, characterized in that: The micro-ring resonator (5) is an arbitrary semiconductor type micro-ring resonator.

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