Wavelength meter based on microcavity soliton optical frequency comb and method for measuring wavelength of to-be-measured light beam

Abstract

The present disclosure provides a wavelength meter based on a microcavity soliton optical frequency comb, configured to measure the wavelength of a to-be-measured light beam, comprising: a forming unit configured to form a microcavity soliton optical frequency comb, comprising: a light source branch configured to emit a first light beam; an auxiliary branch configured to emit an auxiliary light beam; a microcavity connected with the light source branch and the auxiliary branch respectively, and the first light beam and the auxiliary light beam form a microcavity soliton optical frequency comb in the microcavity, wherein the forming unit adjusts the repetition frequency of the microcavity soliton optical frequency comb by adjusting the auxiliary light beam; a to-be-measured unit connected with the forming unit, configured to combine the to-be-measured light beam with the microcavity soliton optical frequency comb; a measurement unit connected with the to-be-measured unit, configured to measure the beat frequency signal of the to-be-measured light beam and the microcavity soliton optical frequency comb, and calculate the wavelength of the to-be-measured light beam based on the beat frequency signal and the repetition frequency of the microcavity soliton optical frequency comb.

Description

Technical Field

[0001] This disclosure relates to the field of microcavity soliton optical frequency comb technology, and in particular to a wavelength meter based on a microcavity soliton optical frequency comb and a method for measuring the wavelength of a beam to be measured. Background Technology

[0002] The measurement of light beam wavelength has been widely used in fields such as length, speed, and angle measurement, and has become an important measurement parameter in precision metrology and precision mechanics. Therefore, research on the accurate measurement of light beam wavelength is of great significance.

[0003] However, current wavelength meters used to detect the wavelength of light beams are complex in structure, expensive to manufacture, and not conducive to integration. Summary of the Invention

[0004] To at least partially overcome the technical defects of at least one or other inventions mentioned above, at least one embodiment of this disclosure proposes a wavelength meter based on a microcavity soliton optical frequency comb and a method for measuring the wavelength of a beam to be measured. By setting a forming unit, multiple microcavity soliton optical frequency combs with different repetition frequencies can be formed for measuring the wavelength of the beam to be measured.

[0005] According to one aspect of the present invention, a wavelength meter based on a microcavity soliton optical frequency comb is provided, configured to measure the wavelength of a beam under test, comprising: a forming unit configured to form a microcavity soliton optical frequency comb, including: a light source branch configured to emit a first beam; an auxiliary branch configured to emit an auxiliary beam; a microcavity connected to the light source branch and the auxiliary branch respectively, wherein the first beam and the auxiliary beam form the microcavity soliton optical frequency comb within the microcavity, wherein the forming unit adjusts the repetition frequency of the microcavity soliton optical frequency comb by adjusting the auxiliary beam; a test unit connected to the forming unit, configured to combine the beam under test with the microcavity soliton optical frequency comb; and a measurement unit connected to the test unit, configured to measure the beat frequency signal of the beam under test and the microcavity soliton optical frequency comb, and calculate the wavelength of the beam under test based on the beat frequency signal and the repetition frequency of the microcavity soliton optical frequency comb.

[0006] In some embodiments, the light source branch includes: a first light source configured to emit a first light beam; and a first circulator disposed between the first light source and the microcavity, configured to allow the first light beam to enter the microcavity in a circumferential manner.

[0007] In some embodiments, the light source branch further includes: a first amplifier connected to the first light source and configured to amplify the power of the first beam; and a first polarization controller disposed between the first amplifier and the first circulator and configured to control the polarization of the first beam from the first amplifier.

[0008] In some embodiments, the auxiliary branch includes: a second light source configured to emit an auxiliary beam; and a second circulator disposed between the second light source and the microcavity, configured to allow the auxiliary beam to enter the microcavity in a circumferential manner and to transmit the microcavity soliton frequency comb to the unit under test.

[0009] In some embodiments, the auxiliary branch further includes: a second amplifier connected to the second light source and configured to amplify the power of the auxiliary beam; and a second polarization controller disposed between the second amplifier and the second circulator and configured to control the polarization of the auxiliary beam from the second amplifier.

[0010] In some embodiments, the unit under test includes: a modulator, through which the beam under test is modulated and emitted; and a beam splitter, disposed between the modulator and the auxiliary branch and connected to the measurement unit, configured to combine the beam under test from the modulator and the microcavity soliton optical frequency comb into a combined beam.

[0011] In some embodiments, the measurement unit includes: a photodetector connected to the unit under test and configured to convert the optical signal of the combined beam into an electrical signal; and an analysis unit connected to the photodetector and configured to calculate the wavelength of the beam under test based on the electrical signal.

[0012] In some embodiments, the microcavity includes a whispering-gallery pattern microcavity.

[0013] According to another aspect of the present invention, a method for measuring the wavelength of a beam under test using the aforementioned wavelength meter is provided, comprising: controlling the light source branch and the auxiliary branch to emit a first beam and the auxiliary beam into the microcavity, respectively; repeatedly adjusting the frequency of the auxiliary beam emitted by the auxiliary branch to adjust the repetition frequency of the microcavity soliton optical frequency comb; determining the absolute value of the number of comb teeth of the microcavity soliton optical frequency comb that beats the beam under test based on the relationship between the repetition frequency and the beat frequency signal; confirming the positive and negative values ​​of the number of comb teeth and the beat frequency signal based on the frequency of the beam under test emitted after modulation by the modulator; and determining the wavelength of the beam under test based on the number of comb teeth of the microcavity soliton optical frequency comb that beats the beam under test.

[0014] According to embodiments of this disclosure, by emitting an auxiliary beam through an auxiliary branch, thermal effects within the microcavity can be suppressed. A microcavity soliton optical frequency comb is formed within the microcavity using an auxiliary first beam. Furthermore, the repetition frequency of the microcavity soliton optical frequency comb can be changed by altering the frequency of the auxiliary beam. In other words, multiple microcavity soliton optical frequency combs with different repetition frequencies can be formed by providing a forming unit. Therefore, when measuring the wavelength of a beam under test, it is not necessary to use a forming device for multiple microcavity soliton optical frequency combs to measure the wavelength of the beam under test. Attached Figure Description

[0015] Figure 1 A schematic diagram of a wavelength meter based on a microcavity soliton optical frequency comb according to an embodiment of the present disclosure is shown.

[0016] Figure 2 A schematic diagram of a microcavity optical frequency comb formed by a forming unit according to an embodiment of the present disclosure is shown.

[0017] Figure 3 A flowchart illustrating a method for measuring the wavelength of a beam under test using the above-described wavelength meter according to an embodiment of the present disclosure is shown; and

[0018] Figure 4 The illustration shows a comparison diagram of the microcavity soliton optical frequency comb before and after adjusting the repetition frequency according to an embodiment of the present disclosure.

[0019] Explanation of reference numerals in the attached figures

[0020] 1: Forming unit;

[0021] 11: Light source branch 11;

[0022] 111: First light source 111;

[0023] 112: First circulator 112;

[0024] 113: First amplifier 113;

[0025] 114: First polarization controller 114;

[0026] 12: Auxiliary branch 12;

[0027] 121: Second light source 121;

[0028] 122: Second circulator 122;

[0029] 123: Second amplifier 123;

[0030] 124: Second polarization controller 124;

[0031] 13: Microcavity 13;

[0032] 2: Unit to be tested 2;

[0033] 21: Modulator 21;

[0034] 22: Beam splitter 22;

[0035] 3: Measurement Unit 3;

[0036] 31: Photodetector 31;

[0037] 32: Analysis Unit. Detailed Implementation

[0038] To make the objectives, technical solutions, and advantages of this disclosure clearer, the following detailed description is provided in conjunction with specific embodiments and the accompanying drawings. However, the invention can be implemented in different forms and should not be construed as being limited to the embodiments set forth herein. Rather, providing these embodiments will make the disclosure thorough and complete, and will fully convey the scope of the invention to those skilled in the art. In the drawings, for clarity, the dimensions and relative dimensions of layers and regions may be exaggerated, and the same reference numerals denote the same elements throughout.

[0039] Hereinafter, embodiments of the present invention 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 invention. In the following detailed description, numerous specific details are set forth to provide a thorough understanding of the embodiments of the invention for ease of explanation. However, it will be apparent that one or more embodiments may be practiced without these specific details. Furthermore, descriptions of well-known structures and techniques are omitted in the following description to avoid unnecessarily obscuring the concept of the invention.

[0040] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the invention. The terms “comprising,” “including,” etc., as used herein indicate the presence of the stated features, steps, operations, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, or components.

[0041] All terms used herein (including technical and scientific terms) have the meanings commonly understood by those skilled in the art, unless otherwise defined. It should be noted that the terms used herein are to be interpreted in a manner consistent with the context of this specification, and not in an idealized or overly rigid way.

[0042] To facilitate understanding of the technical solutions of this invention by those skilled in the art, the following technical terms are explained below.

[0043] When using expressions such as "at least one of A, B, and C," the expression should generally be interpreted in accordance with the meaning commonly understood by a person skilled in the art (e.g., "a system having at least one of A, B, and C" should include, but is not limited to, systems having A alone, having B alone, having C alone, having A and B, having A and C, having B and C, and / or having A, B, and C, etc.). Similarly, when using expressions such as "at least one of A, B, or C," the expression should generally be interpreted in accordance with the meaning commonly understood by a person skilled in the art (e.g., "a system having at least one of A, B, or C" should include, but is not limited to, systems having A alone, having B alone, having C alone, having A and B, having A and C, having B and C, and / or having A, B, and C, etc.).

[0044] Figure 1 A schematic diagram of a wavelength meter based on a microcavity soliton optical frequency comb according to an embodiment of the present disclosure is shown. Figure 2 A schematic diagram of a microcavity soliton optical frequency comb generated by a wavelength meter based on a microcavity soliton optical frequency comb according to an embodiment of the present disclosure is shown.

[0045] like Figure 1 and Figure 2 As shown, this disclosure provides a wavelength meter based on a microcavity soliton optical frequency comb. The wavelength meter is configured to measure the wavelength of a beam under test and includes a forming unit 1, a test unit 2, and a measuring unit 3.

[0046] Specifically, forming unit 1 is configured to form a microcavity soliton optical frequency comb, including a light source branch 11, an auxiliary branch 12, and a microcavity 13. Unit 2 under test (UTP) is connected to forming unit 1 and configured to combine the test beam with the microcavity soliton optical frequency comb. Measurement unit 3 is connected to UTP 2 and configured to measure the beat frequency signals of the test beam and the microcavity soliton optical frequency comb, and calculate the wavelength of the test beam based on the beat frequency signals and the repetition frequency of the microcavity soliton optical frequency comb.

[0047] In detail, the light source branch 11 is configured to emit a first beam. The auxiliary branch 12 is configured to emit an auxiliary beam. The microcavity 13 is connected to both the light source branch 11 and the auxiliary branch 12, and the first beam and the auxiliary beam form a microcavity soliton optical frequency comb within the microcavity 13. The forming unit 1 adjusts the repetition frequency of the microcavity soliton optical frequency comb by adjusting the auxiliary beam. The microcavity 13 can be a whispering-gallery mode microcavity 13, which has third-order nonlinearity and anomalous dispersion, and can perform cascaded four-wave mixing.

[0048] According to embodiments of this disclosure, by emitting an auxiliary beam through an auxiliary branch 12, thermal effects within the microcavity 13 can be suppressed. A microcavity soliton optical frequency comb is formed within the microcavity 13 by assisting the first beam. Furthermore, the repetition frequency of the microcavity soliton optical frequency comb can be changed by altering the frequency of the auxiliary beam. In other words, multiple microcavity soliton optical frequency combs with different repetition frequencies can be formed by providing the forming unit 1. Therefore, when measuring the wavelength of a beam under test, it is not necessary to use a forming device for multiple microcavity soliton optical frequency combs to measure the wavelength of the beam under test.

[0049] In some embodiments, the light source branch 11 includes a first light source 111, a first circulator 112, a first amplifier 113, and a first polarization controller 114.

[0050] Specifically, a first light source 111 is configured to emit a first beam. A first circulator 112 is disposed between the first light source 111 and the microcavity 13 and is configured to allow the first beam to enter the microcavity 13 in a circumferential manner. A first amplifier 113 is connected to the first light source 111 and is configured to amplify the power of the first beam. A first polarization controller 114 is disposed between the first amplifier 113 and the first circulator 112 and is configured to control the polarization of the first beam from the first amplifier 113. The first light source 111 may be a tunable pumped light source, such as an on-chip semiconductor light source.

[0051] In some embodiments, the auxiliary branch 12 includes a second light source 121, a second circulator 122, a second amplifier 123, and a second polarization controller 124.

[0052] Specifically, the second light source 121 is configured to emit an auxiliary beam. A second circulator 122 is disposed between the second light source 121 and the microcavity 13, configured to allow the auxiliary beam to enter the microcavity 13 in a circumferential manner and to transmit the microcavity soliton frequency comb to the unit under test 2. A second amplifier 123 is connected to the second light source 121 and configured to amplify the power of the auxiliary beam. A second polarization controller 124 is disposed between the second amplifier 123 and the second circulator 122, configured to control the polarization of the auxiliary beam from the second amplifier 123. The second light source 121 can be a tunable pumped light source. The first amplifier 113 and the second amplifier 123 can be fiber amplifiers, used to amplify the power of the first beam and the auxiliary beam.

[0053] The first polarization controller 114 and the second polarization controller 124 can be fiber optic polarization controllers, which can be used to control the polarization of the first beam and the auxiliary beam. The first circulator 112 and the second circulator 122 can be fiber optic circulators, which can be used to transmit the first beam and the auxiliary beam to the microcavity 13 in a loop.

[0054] In some embodiments, the unit under test 2 includes a modulator 21 and a beam splitter 22.

[0055] Specifically, the beam to be tested is modulated by modulator 21 and then emitted. Beam splitter 22 is disposed between modulator 21 and auxiliary branch 12 and connected to measurement unit 3, and is configured to combine the beam to be tested from modulator 21 and microcavity soliton optical frequency comb into a combined beam. Beam splitter 22 can be an optical fiber beam splitter 22.

[0056] In some embodiments, the measurement unit 3 includes a photodetector 31 and an analysis unit 32.

[0057] Specifically, photodetector 31 is connected to the unit under test 2 and is configured to convert the optical signal of the combined beam into an electrical signal. Analysis unit 32 is connected to photodetector 31 and is configured to calculate the wavelength of the beam under test based on the electrical signal. Analysis unit 32 may include a real-time spectrum analyzer, which can be used for real-time detection of electrical signals.

[0058] In some embodiments, the microcavity 13 includes a whispering-gallery pattern microcavity 13.

[0059] Figure 3 A flowchart illustrating a method for measuring the wavelength of a beam under test using the above-described wavelength meter according to an embodiment of the present disclosure is shown. Figure 4 The illustration shows a comparison diagram of the microcavity soliton optical frequency comb before and after adjusting the repetition frequency according to an embodiment of the present disclosure.

[0060] like Figure 3 As shown, the method 300 may include performing operations S301 to S305.

[0061] In operation S310: control the light source branch 11 and the auxiliary branch 12 to emit the first beam and the auxiliary beam to the microcavity 13 respectively.

[0062] In operation S320: Repeatedly adjust the frequency of the auxiliary beam emitted by the auxiliary branch 12 to adjust the repetition frequency of the microcavity soliton optical frequency comb.

[0063] In operation S330: Based on the relationship between the repetition frequency and the beat frequency signal, determine the absolute value of the number of comb teeth of the microcavity soliton optical frequency comb that beats the beam under test.

[0064] In operation S340: Based on the frequency of the beam to be tested emitted after being modulated by modulator 21, confirm the positive and negative values ​​of the number of comb teeth and the beat frequency.

[0065] In operation S350: the wavelength of the beam under test is determined based on the number of teeth of the microcavity soliton optical frequency comb that beats the beam under test.

[0066] Specifically, the frequency of the beam under test can be expressed as ω = ωp +nf rep +ω beat Wherein, ω p f is the frequency of the first light source 111. rep ω represents the repetition frequency, and n represents the number of comb teeth corresponding to the beat frequency of the detection laser. beat To detect the beat frequency of the laser and its corresponding comb teeth. rep and ω beat The value of ω can be obtained through analysis unit 32. p The value can be obtained by calibration with a laser of known wavelength. The wavelength of the beam under test can be obtained by the frequency of the beam under test.

[0067] In detail, by repeatedly adjusting the frequency of the auxiliary beam, the repetition frequency of the microcavity soliton optical frequency comb can be adjusted. By scanning the repetition frequency and observing the changes in the beat frequency signal and the slope of the repetition frequency with the frequency of the auxiliary beam, the absolute value of the number of comb teeth of the microcavity soliton optical frequency comb that beats the beam under test can be determined. By adjusting the modulation frequency of the modulator 21, the frequency of the beam under test can be adjusted. For example, adjusting the modulation frequency increases the frequency of the beam under test by 5 MHz, and then the positive and negative values ​​of the number of comb teeth and the beat frequency signal can be confirmed by observing the changes in the beat frequency.

[0068] Based on the above description, those skilled in the art should have a clear understanding of the wavelength meter based on the microcavity soliton optical frequency comb and the method for measuring the wavelength of the beam to be measured according to the present invention.

[0069] It should also be noted that the directional terms mentioned in the embodiments, such as "up," "down," "front," "back," "left," and "right," are only for reference to the directions in the accompanying drawings and are not intended to limit the scope of protection of this disclosure. Throughout the drawings, the same elements are represented by the same or similar reference numerals. Conventional structures or constructions will be omitted where they may cause confusion in understanding this disclosure, and the shapes and dimensions of the components in the drawings do not reflect actual size and proportion, but are only schematic representations of the embodiments of this disclosure.

[0070] Unless otherwise stated, the numerical parameters in this specification and the appended claims are approximate values ​​and can be varied according to desired characteristics derived from the content of this disclosure. Specifically, all figures used in the specification and claims to indicate composition, reaction conditions, etc., should be understood to be modified by the term "about" in all cases. Generally, this means that a specific amount varies by ±10% in some embodiments, ±5% in some embodiments, ±1% in some embodiments, and ±0.5% in some embodiments.

[0071] The use of ordinal numbers such as "first," "second," "third," etc., in the specification and claims to modify the corresponding elements does not imply that the element has any ordinal number, nor does it represent the order of one element with another element, or the order of manufacturing methods. The use of these ordinal numbers is only to enable a named element to be clearly distinguished from another element with the same name.

[0072] Furthermore, unless specifically described or required to occur in a specific order, the order of the above steps is not limited to those listed above and can be varied or rearranged according to the desired design. Moreover, the above embodiments can be used in combination with each other or with other embodiments based on design and reliability considerations; that is, technical features from different embodiments can be freely combined to form more embodiments.

[0073] The above specific embodiments further illustrate the purpose, technical solutions and beneficial effects of this disclosure. It should be understood that the above are only specific embodiments of this disclosure and are not intended to limit this disclosure. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this disclosure should be included within the protection scope of this disclosure.

Claims

1. A wavelength meter based on a microcavity soliton optical frequency comb, configured to measure the wavelength of a beam under test, comprising: Forming units, configured to form microcavity soliton optical frequency combs, include: The light source branch is configured to emit the first beam; The auxiliary branch is configured to emit an auxiliary beam; A microcavity is connected to the light source branch and the auxiliary branch respectively. The first beam and the auxiliary beam form a microcavity soliton optical frequency comb in the microcavity. The forming unit adjusts the repetition frequency of the microcavity soliton optical frequency comb by adjusting the frequency of the auxiliary beam. The unit under test, connected to the forming unit, is configured to combine the beam under test with the microcavity soliton optical frequency comb; A measurement unit, connected to the unit under test, is configured to measure the beat frequency signal of the beam under test and the microcavity soliton optical frequency comb, and calculate the wavelength of the beam under test based on the beat frequency signal and the repetition frequency of the microcavity soliton optical frequency comb; The unit to be tested includes: A modulator, through which the beam to be measured is modulated before being emitted; A beam splitter, disposed between the modulator and the auxiliary branch and connected to the measurement unit, is configured to combine the beam under test from the modulator and the microcavity soliton frequency comb into a combined beam.

2. The wavelength meter according to claim 1, characterized in that, The light source branch includes: The first light source is configured to emit the first beam of light; A first circulator, disposed between the first light source and the microcavity, is configured to allow the first light beam to enter the microcavity in a circumferential manner.

3. The wavelength meter according to claim 2, characterized in that, The light source branch also includes: A first amplifier, connected to the first light source, is configured to amplify the power of the first beam; A first polarization controller, disposed between the first amplifier and the first circulator, is configured to control the polarization of a first beam from the first amplifier.

4. The wavelength meter according to claim 1, characterized in that, The auxiliary branch includes: The second light source is configured to emit an auxiliary beam; A second circulator, disposed between the second light source and the microcavity, is configured to allow the auxiliary beam to enter the microcavity in a circumferential manner and to transmit the microcavity soliton frequency comb to the unit under test.

5. The wavelength meter according to claim 4, characterized in that, The auxiliary branch also includes: A second amplifier, connected to the second light source, is configured to amplify the power of the auxiliary beam; A second polarization controller, disposed between the second amplifier and the second circulator, is configured to control the polarization of an auxiliary beam from the second amplifier.

6. The wavelength meter according to claim 1, characterized in that, The measurement unit includes: A photodetector, connected to the unit under test, is configured to convert the optical signal of the combined beam into an electrical signal. An analysis unit, connected to the photodetector, is configured to calculate the wavelength of the beam under test based on the electrical signal.

7. The wavelength meter according to claim 1, characterized in that, The microcavity includes a whispering-gallery pattern microcavity.

8. A method for measuring the wavelength of a beam under test using a wavelength meter according to any one of claims 1-7, comprising: The light source branch and the auxiliary branch are respectively controlled to emit the first beam and the auxiliary beam into the microcavity; The frequency of the auxiliary beam emitted by the auxiliary branch is repeatedly adjusted to adjust the repetition frequency of the microcavity soliton optical frequency comb; Based on the relationship between the repetition frequency and the beat frequency signal, the absolute value of the number of comb teeth of the microcavity soliton optical frequency comb that beats the beam under test is determined. Based on the frequency of the beam to be tested emitted after being modulated by the modulator, the positive and negative values ​​of the number of comb teeth and the positive and negative values ​​of the beat frequency signal are confirmed. The wavelength of the beam under test is determined based on the number of teeth of the microcavity soliton optical frequency comb that beats the beam under test.

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