A multi-microwave local oscillator source generating device based on micro-resonant cavity

Abstract

The present disclosure provides a multi-microwave local oscillator source generating device based on a micro-resonant cavity, characterized in that it includes: a beam splitter, used for performing beam splitting processing on a pump light to obtain a first pump light and a second pump light; a first micro-resonant cavity, used for performing four-wave mixing processing on the first pump light to obtain a first optical frequency comb, wherein the first optical frequency comb has a first frequency interval; a second micro-resonant cavity, used for performing four-wave mixing processing on the second pump light to obtain a second optical frequency comb, wherein the second optical frequency comb has a second frequency interval; and a photodetector, used for performing beat frequency processing on the first optical frequency comb and the second optical frequency comb to obtain a multi-microwave local oscillator source with a third frequency interval.

Description

Technical Field

[0001] The present disclosure relates to the field of integrated optoelectronics and microwave photons, and in particular to a multi-microwave local oscillator source generating device based on a micro-resonant cavity. Background Art

[0002] With the development of optoelectronics and microwave photonics technology, photonics technology is increasingly being used to assist microwave technology to solve problems that are difficult to solve with microwaves alone. For example, microwave technology is limited by the "electronic bottleneck" and is stretched in high-frequency and large-bandwidth applications. However, combined with photonics technology, the use of optical methods to generate, process and transmit microwave signals can greatly break through bandwidth limitations and expand microwaves to a wider range of applications. Integrated microwave photonics can meet people's needs for small, low-power, high-bandwidth microwave photonic devices, and therefore has attracted more and more attention from researchers.

[0003] In radar systems and satellite communication systems, channelized transmitters and channelized receivers are very important components. However, channelized transmitters and channelized receivers are bulky, power-hungry, and complex. Using the optical frequency comb of a micro-resonant cavity to generate multiple microwave local oscillator sources can reduce the size of channelized transmitters and receivers and simplify the system structure. Summary of the invention

[0004] In order to solve the above problems in the prior art, the present disclosure provides a multi-microwave local oscillator source generating device based on a micro-resonant cavity, which overcomes the limitations of traditional electronic technology in terms of weight, volume, bandwidth and electromagnetic compatibility.

[0005] The present disclosure provides a multi-microwave local oscillator source generating device based on a micro-resonant cavity, comprising: a beam splitter, used for performing beam splitting processing on a pump light to obtain a first pump light and a second pump light; a first micro-resonant cavity, used for performing four-wave mixing processing on the first pump light to obtain a first optical frequency comb, wherein the first optical frequency comb has a first frequency interval; a second micro-resonant cavity, used for performing four-wave mixing processing on the second pump light to obtain a second optical frequency comb, wherein the second optical frequency comb has a second frequency interval; and a photodetector, used for performing beat frequency processing on the first optical frequency comb and the second optical frequency comb to obtain a multi-microwave local oscillator source with a third frequency interval.

[0006] Furthermore, the first micro-resonant cavity and the second micro-resonant cavity are micro-ring resonant cavities, micro-disk resonant cavities, or micro-sphere resonant cavities.

[0007] Furthermore, the first microresonant cavity and the second microresonant cavity have different resonant cavity radii.

[0008] Furthermore, the first micro-resonant cavity and the second micro-resonant cavity are made of silicon, silicon nitride or any other nonlinear material.

[0009] Furthermore, the working bandwidth of the photodetector is smaller than the frequency comb interval of the optical frequency combs generated by the first microresonator and the second microresonator.

[0010] Furthermore, the device also includes: a narrow linewidth laser for providing pump light; and an optical amplifier for amplifying the power of the pump light and outputting it to the beam splitter.

[0011] Furthermore, the optical amplifier is a semiconductor optical amplifier or a fiber amplifier, the pump light power output by the optical amplifier is greater than the threshold power of the first microresonant cavity and the second microresonant cavity, and the gain wavelength range of the optical amplifier includes the laser wavelength output by the narrow linewidth laser.

[0012] Furthermore, the device also includes: a beam combiner, which is used to combine the first optical frequency comb and the second optical frequency comb to obtain an optical frequency comb, and output it to the photodetector.

[0013] Furthermore, the narrow linewidth laser, the optical amplifier, the first microresonant cavity and the second microresonant cavity are all arranged on a temperature controller, and each temperature controller is used to control the operating temperature of the narrow linewidth laser, the optical amplifier, the first microresonant cavity and the second microresonant cavity respectively.

[0014] Furthermore, the operating temperature of the narrow linewidth laser is 20-40°C, the operating temperature of the first microresonant cavity and the second microresonant cavity is 20-60°C, and the operating temperature of the optical amplifier is 25°C.

[0015] The present invention provides a multi-microwave local oscillator source generating device based on a micro-resonant cavity, which uses a narrow linewidth laser as a pump source, excites two optical frequency combs with different repetition frequencies through two micro-resonant cavities, and then beats the two optical frequency combs through a photodetector, thereby finally realizing multi-microwave local oscillator sources with equal frequency intervals. The multi-microwave local oscillator sources generated by the device have a large bandwidth and can cover the S-Ku band. The entire device structure is highly integrated, small in size, and simple in structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] For a more complete understanding of the present disclosure and its advantages, reference will now be made to the following description taken in conjunction with the accompanying drawings, in which:

[0017] Figure 1 The structure diagram of a multi-microwave local oscillator source generating device based on a micro-resonant cavity according to an embodiment of the present disclosure is schematically shown;

[0018] Figure 2 The diagram schematically shows an optical frequency comb with different frequency intervals and a schematic diagram of beat frequency generation of multiple microwave local oscillator sources according to an embodiment of the present disclosure. DETAILED DESCRIPTION

[0019] Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings. However, it should be understood that these descriptions are exemplary only and are not intended to limit the scope of the present disclosure. In the following detailed description, for ease of explanation, many specific details are set forth to provide a comprehensive understanding of the embodiments of the present disclosure. However, it is apparent that one or more embodiments may also be implemented without these specific details. In addition, in the following description, descriptions of known structures and technologies are omitted to avoid unnecessary confusion of the concepts of the present disclosure.

[0020] The terms used herein are only for describing specific embodiments and are not intended to limit the present disclosure. The terms "comprise", "include", etc. used herein indicate the existence of the features, steps, operations and / or components, but do not exclude the existence or addition of one or more other features, steps, operations or components.

[0021] All terms (including technical and scientific terms) used herein have the meanings commonly understood by those skilled in the art, unless otherwise defined. It should be noted that the terms used herein should be interpreted as having a meaning consistent with the context of this specification, and should not be interpreted in an idealized or overly rigid manner.

[0022] Figure 1 The schematic diagram shows the structure of a multi-microwave local oscillator source generating device based on a micro-resonant cavity according to an embodiment of the present disclosure.

[0023] like Figure 1 As shown, the multi-microwave local oscillator source generating device based on the micro-resonant cavity includes:

[0024] The output end of the narrow linewidth laser 1 is connected to the input end of the optical amplifier 2 to provide pump light.

[0025] In the embodiment of the present disclosure, the narrow linewidth laser 1 can be a distributed Bragg reflector laser or a distributed feedback laser, and its output laser wavelength is tunable, and the wavelength tuning range covers the C band, and the corresponding output laser wavelength is 1549.1nm to 1551.3nm, the laser linewidth is 100kHz, and the signal-to-noise ratio is higher than 45dB. Among them, the pump light frequency output by the narrow linewidth laser 1 is f0.

[0026] The output end of the optical amplifier 2 is connected to the input end of the beam splitter 3 and is used to amplify the power of the pump light and then output it to the beam splitter 3 .

[0027] In the embodiments of the present disclosure, the optical amplifier 2 is a semiconductor optical amplifier or a fiber amplifier, and its saturated output power is greater than 100 mW. The pump light power outputted by the optical amplifier 2 is greater than the threshold power of the first micro-resonant cavity and the second micro-resonant cavity, so as to ensure that the pump light can generate sufficient four-wave mixing effect with the first micro-resonant cavity and the second micro-resonant cavity to generate an optical frequency comb, and its gain wavelength range includes the laser wavelength outputted by the narrow linewidth laser, that is, its operating band also covers the C band.

[0028] The beam splitter 3 has a first output end connected to the input end of the first microresonator 4 and a second output end connected to the input end of the second microresonator 5, and is used to split the pump light to obtain the first pump light and the second pump light, and output the first pump light and the second pump light to the first microresonator 4 and the second microresonator 5 respectively.

[0029] In the embodiment of the present disclosure, the beam splitter 3 may be a fiber beam splitter with a splitting ratio of 1:1 and an insertion loss lower than 1 dB.

[0030] The first microresonator 4 has an output end connected to a first input end of a beam combiner 6 and is used to perform four-wave mixing on the first pump light to obtain a first optical frequency comb, wherein the first optical frequency comb has a first frequency interval.

[0031] The second microresonator 5 has an output end connected to the second input end of the beam combiner 6 and is used to perform four-wave mixing on the second pump light to obtain a second optical frequency comb, wherein the second optical frequency comb has a second frequency interval.

[0032] In the embodiment of the present disclosure, the first micro-resonant cavity 4 and the second micro-resonant cavity 5 have different resonant cavity radii and different free spectral regions to ensure the generation of multiple local oscillator source signals. The first micro-resonant cavity 4 and the second micro-resonant cavity 5 can be micro-ring resonant cavities, micro-disk resonant cavities, or micro-sphere resonant cavities, and the pump light output by the beam splitter 3 is respectively input into the first micro-resonant cavity 4 and the second micro-resonant cavity 5 through optical fiber coupling. For example, the first micro-resonant cavity 4 and the second micro-resonant cavity 5 are micro-ring resonant cavities, which are made of silicon nitride material. The frequency intervals of the optical frequency combs generated by the first micro-resonant cavity 4 and the second micro-resonant cavity 5 are different. The frequency interval of the first optical frequency comb generated by the first micro-resonant cavity 4 is recorded as f1, and the frequency interval of the second optical frequency comb generated by the second micro-resonant cavity 5 is recorded as f2.

[0033] Among them, the first optical frequency comb and the second optical frequency comb have one comb tooth that completely overlaps, and this comb tooth is the pump light with a frequency of f0. Then the frequencies of the first optical frequency comb are f0, f0+f1, f0+2f1, ..., f0+nf1; the frequencies of the second optical frequency comb are f0, f0+f2, f0+2f2, ..., f0+nf2.

[0034] In other embodiments of the present disclosure, the first micro-resonant cavity 4 and the second micro-resonant cavity 5 may also be made of silicon or any other nonlinear material, and the resonant cavity radius is preferably 100 μm to 200 μm.

[0035] The output end of the beam combiner 6 is connected to the input end of the photodetector 7 , and is used to combine the first optical frequency comb and the second optical frequency comb to obtain an optical frequency comb, and output it to the photodetector 7 .

[0036] In the embodiment of the present disclosure, the combiner 6 may be a fiber optic splitter with an insertion loss lower than 1 dB.

[0037] The photoelectric detector 7 is used to beat the optical frequency comb beam combined by the beam combiner 6 to obtain a multi-microwave local oscillator source with a third frequency interval.

[0038] In the embodiment of the present disclosure, the working band of the photodetector 7 also covers the C band, and the responsivity is greater than 0.5A / W. Figure 2 As shown, the frequencies of the multi-microwave local oscillator sources at the third frequency interval obtained after the photoelectric detector 7 beats the frequency are f1-f2, 2(f1-f2), 3(f1-f2), ..., n(f1-f2).

[0039] In the embodiment of the present disclosure, in order to prevent the occurrence of high-order harmonics, the working bandwidth of the photodetector 7 is smaller than the frequency comb interval of the optical frequency comb generated by the first microresonator 4 and the second microresonator 5 .

[0040] According to the embodiment of the present disclosure, in order to make each component reach the optimal operating temperature and the output optical frequency comb has a better quality, the narrow linewidth laser 1, the optical amplifier 2, the first micro-resonant cavity 4 and the second micro-resonant cavity 5 are all arranged on a temperature controller, and each temperature controller is used to control the operating temperature of the narrow linewidth laser 1, the optical amplifier 2, the first micro-resonant cavity 4 and the second micro-resonant cavity 5. Among them, through theoretical simulation and experimental testing, the optimal operating temperature of the narrow linewidth laser 1 is 20-40°C, the optimal operating temperature of the optical amplifier 2 is 25°C, and the optimal operating temperature of the first micro-resonant cavity 4 and the second micro-resonant cavity 5 is 20-60°C.

[0041] like Figure 2 The figure shows the schematic diagram of optical frequency combs with different frequency intervals and beat frequency generation of multiple microwave local oscillator sources. Figure 2As shown, the first micro-resonant cavity 4 and the second micro-resonant cavity 5 generate an optical frequency comb under the action of four-wave mixing between the pump light and the micro-resonant cavity, and use different comb teeth of two optical frequency combs with different frequency intervals to perform difference frequency beat frequency to generate multi-microwave local oscillator signals, thereby realizing multi-channel RF signal forwarding, which can well meet the needs of new satellite communication systems and can be well applied in dense wavelength division multiplexing systems.

[0042] It should be noted that the device structure provided in the above embodiment does not constitute a limitation on the present device. The number, shape and size of the devices in the device may be modified according to actual conditions, and the configuration of the devices may be more complicated.

[0043] It will be appreciated by those skilled in the art that the features described in the various embodiments and / or claims of the present disclosure may be combined and / or combined in a variety of ways, even if such combinations and / or combinations are not explicitly described in the present disclosure. In particular, the features described in the various embodiments and / or claims of the present disclosure may be combined and / or combined in a variety of ways without departing from the spirit and teachings of the present disclosure. All of these combinations and / or combinations fall within the scope of the present disclosure.

[0044] Although the present disclosure has been shown and described with reference to specific exemplary embodiments of the present disclosure, it should be understood by those skilled in the art that various changes in form and details may be made to the present disclosure without departing from the spirit and scope of the present disclosure as defined by the appended claims and their equivalents. Therefore, the scope of the present disclosure should not be limited to the above-mentioned embodiments, but should be determined not only by the appended claims, but also by the equivalents of the appended claims.

Claims

1. A multi-microwave local oscillator source generating device based on a micro-resonant cavity, characterized in that: include: A narrow linewidth laser, an optical amplifier, a beam splitter, a first micro-resonant cavity, a second micro-resonant cavity, a beam combiner, and a photodetector; The output end of the narrow linewidth laser is connected to the input end of the optical amplifier to provide pump light; The output end of the optical amplifier is connected to the input end of the beam splitter, and is used to amplify the power of the pump light and output it to the beam splitter; The first output end of the beam splitter is connected to the input end of the first microresonant cavity, and the second output end is connected to the input end of the second microresonant cavity, and is used to split the pump light to obtain the first pump light and the second pump light, and output the first pump light and the second pump light to the first microresonant cavity and the second microresonant cavity respectively; The output end of the first microresonator is connected to the first input end of the beam combiner, and is used to perform four-wave mixing on the first pump light to obtain a first optical frequency comb, wherein the first optical frequency comb has a first frequency interval; The output end of the second microresonator is connected to the second input end of the beam combiner, and is used to perform four-wave mixing on the second pump light to obtain a second optical frequency comb, wherein the second optical frequency comb has a second frequency interval; The output end of the beam combiner is connected to the input end of the photodetector, and is used to combine the first optical frequency comb and the second optical frequency comb to obtain an optical frequency comb, and output it to the photodetector; The photoelectric detector is used to beat the optical frequency comb after being combined by the beam combiner to obtain a multi-microwave local oscillator source with a third frequency interval.

2. The multi-microwave local oscillator source generating device based on a micro-resonant cavity according to claim 1 is characterized in that: The first micro-resonant cavity and the second micro-resonant cavity are micro-ring resonant cavities, micro-disk resonant cavities, or micro-sphere resonant cavities.

3. The multi-microwave local oscillator source generating device based on a micro-resonant cavity according to claim 2 is characterized in that: The first microresonant cavity and the second microresonant cavity have different resonant cavity radii.

4. The multi-microwave local oscillator source generating device based on a micro-resonant cavity according to claim 1 is characterized in that: The first micro-resonant cavity and the second micro-resonant cavity are made of silicon, silicon nitride or any other nonlinear material.

5. The multi-microwave local oscillator source generating device based on a micro-resonant cavity according to claim 1 is characterized in that: The operating bandwidth of the photodetector is smaller than the frequency comb interval of the optical frequency combs generated by the first microresonator and the second microresonator.

6. The multi-microwave local oscillator source generating device based on a micro-resonant cavity according to claim 1 is characterized in that: The optical amplifier is a semiconductor optical amplifier or a fiber amplifier, the pump light power output by the optical amplifier is greater than the threshold power of the first microresonant cavity and the second microresonant cavity, and the gain wavelength range of the optical amplifier includes the laser wavelength output by the narrow linewidth laser.

7. The multi-microwave local oscillator source generating device based on a micro-resonant cavity according to claim 1 is characterized in that: The device also includes: A beam combiner is used to combine the first optical frequency comb and the second optical frequency comb to obtain an optical frequency comb, and output it to the photodetector.

8. The multi-microwave local oscillator source generating device based on a micro-resonant cavity according to claim 1 is characterized in that: The narrow linewidth laser, the optical amplifier, the first microresonant cavity and the second microresonant cavity are all arranged on a temperature controller, and the temperature controller is used to control the operating temperature of the narrow linewidth laser, the optical amplifier, the first microresonant cavity and the second microresonant cavity respectively.

9. The multi-microwave local oscillator source generating device based on a micro-resonant cavity according to claim 8, characterized in that: The operating temperature of the narrow linewidth laser is 20-40°C, the operating temperature of the first microresonant cavity and the second microresonant cavity is 20-60°C, and the operating temperature of the optical amplifier is 25°C.

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