Mach-Zehnder modulation device and electro-optical modulator
By optimizing the arrangement of waveguide arms and RF electrodes in the Mach-Zehnder modulator, especially by placing the anti-phase modulation section at the front end and adopting a folded design, the problem of poor optical bandwidth compensation in existing modulators has been solved, achieving higher modulation bandwidth and modulation efficiency.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- NANJING LYCORE TECH CO LTD
- Filing Date
- 2025-04-02
- Publication Date
- 2026-04-17
AI Technical Summary
Existing Mach-Zehnder modulators have limited optical bandwidth compensation effects, resulting in low modulation bandwidth. Furthermore, as the modulation frequency increases, electrode losses increase, leading to decreased modulation efficiency and signal distortion.
Design a Mach-Zehnder modulation device, including an inverting modulation section, an in-phase modulation section and a basic modulation section extending sequentially along the optical signal transmission direction. The inverting modulation section is located in the first modulation region. By optimizing the arrangement of the waveguide arm and the radio frequency electrode, especially by arranging the inverting modulation section at the front end, the optical bandwidth compensation effect is optimized, and a folded design is adopted to reduce the length and improve the modulation efficiency.
It improves the optical bandwidth compensation effect and modulation efficiency of the modulator, reduces transmission loss at high frequencies, and ensures stable modulation of optical signals, making it suitable for electro-optic modulators.
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Figure CN224137575U_ABST
Abstract
Description
Technical Field
[0001] This disclosure relates to the field of optical communications, and in particular to a Mach-Zehnder modulation device and an electro-optic modulator. Background Technology
[0002] The Mach-Zehnder modulator achieves optical signal modulation based on the electro-optic effect. Its core structure includes two parallel optical waveguide arms and driving electrodes covering the waveguides. When a modulation voltage is applied to the electrodes, the refractive index of the waveguide material changes, causing a phase difference in the optical signals between the two waveguide arms. By dynamically controlling this phase difference, the output light intensity can be made to change linearly with the electrical signal, thereby achieving modulation.
[0003] However, existing modulators still suffer from the following problems: limited optical bandwidth compensation and low modulation bandwidth. Furthermore, as the modulation frequency increases, electrode losses increase, leading to decreased modulation efficiency and signal distortion, thus limiting the overall performance of the modulator. Utility Model Content
[0004] In view of the above problems, this disclosure provides a Mach-Zehnder modulation device that can optimize the modulator's compensation effect on optical bandwidth, thereby improving modulation bandwidth and modulation efficiency. This disclosure also provides an electro-optic modulator.
[0005] According to a first aspect of this disclosure, a Mach-Zehnder modulation device is provided, comprising a first modulation region and a second modulation region extending sequentially along the optical signal transmission direction; or a first modulation region, a turning region, and a second modulation region extending sequentially along the optical signal transmission direction, with the turning region connecting the first modulation region and the second modulation region. The Mach-Zehnder modulation device includes: a first waveguide arm and a second waveguide arm, and radio frequency (RF) electrodes. The first and second waveguide arms are arranged sequentially without crossing, and each waveguide arm has an optical signal modulation segment. The RF electrodes include a plurality of non-crossing strip electrodes arranged sequentially, configured to apply an RF voltage to the first waveguide arm and / or the second waveguide arm. Along the direction of optical signal transmission, the optical signal modulation section includes, in sequence, an in-phase modulation section, a basic modulation section, and a basic modulation section. The in-phase modulation section is located in the first modulation region, and the basic modulation section is located in the second modulation region. The first waveguide arm and the second waveguide arm generate a certain phase difference in the basic modulation section. The first waveguide arm and the second waveguide arm generate a phase difference in the in-phase modulation section that is in phase with the phase difference generated in the basic modulation section. The first waveguide arm and the second waveguide arm generate a phase difference in the in-phase modulation section that is out of phase with the phase difference generated in the basic modulation section.
[0006] In some embodiments, the in-phase modulation segment and the out-of-phase modulation segment are of equal length.
[0007] In some embodiments, the radio frequency electrode includes: an outer ground electrode, a negative signal electrode, a middle ground electrode, a positive signal electrode, and an inner ground electrode arranged in sequence without crossing.
[0008] In some embodiments, the radio frequency electrode includes a first spacer group and a second spacer group among a plurality of strip electrodes, either adjacent or spaced apart from adjacent strip electrodes. Specifically, in a direction perpendicular to the optical signal transmission direction, the first spacer group includes a first spacer located above the positive signal electrode and below the negative signal electrode, and the second spacer group includes a second spacer located below the positive signal electrode and above the negative signal electrode. Specifically, in the inverting modulation section, a first waveguide arm is arranged within any first spacer of the first spacer group, and a second waveguide arm is arranged within any second spacer of the second spacer group; and in the basic modulation section and the in-phase modulation section, a first waveguide arm is arranged within any second spacer of the second spacer group, and a second waveguide arm is arranged within any first spacer of the first spacer group.
[0009] In some embodiments, the Mach-Zehnder modulation device is a strip-shaped Mach-Zehnder modulation device, including a first modulation region and a second modulation region extending sequentially along the optical signal transmission direction, wherein the in-phase modulation segment is located in the second modulation region.
[0010] In some embodiments, the Mach-Zehnder modulation device is a folded Mach-Zehnder modulation device, including a first modulation region, a turning region and a second modulation region extending sequentially along the optical signal transmission direction, the turning region connecting the first modulation region and the second modulation region, wherein the first waveguide arm and the second waveguide arm are folded in an overall shape and are arranged sequentially without crossing in the turning region, and the radio frequency electrode includes a plurality of strip electrodes that are folded in an overall shape and are arranged sequentially without crossing.
[0011] In some embodiments, the in-phase modulation section is located in the first modulation region, such that the optical signal enters the in-phase modulation section from the out-of-phase modulation section and then enters the basic modulation section via the turning region.
[0012] In some embodiments, the first waveguide arm and the second waveguide arm turn synchronously with the RF electrode; or the first waveguide arm and the second waveguide arm lag behind the RF electrode in turning; or the first waveguide arm and the second waveguide arm lead the RF electrode in turning.
[0013] In some embodiments, the folded Mach-Zehnder modulation device further includes: a beam splitter for splitting the input optical signal into two paths and then feeding them into the first waveguide arm and the second waveguide arm respectively; and a beam combiner for combining the two optical signals from the first waveguide arm and the second waveguide arm and then outputting them.
[0014] According to a second aspect of this disclosure, an electro-optic modulator is provided, including the Mach-Zehnder modulation device described in the above embodiments.
[0015] In some embodiments of this disclosure, by setting an anti-phase modulation segment in the first modulation region, the optical bandwidth compensation effect of the modulator can be optimized.
[0016] It should be understood that the above description is only an overview of the technical solution of this disclosure. In order to better understand the technical means of this disclosure and to implement it in accordance with the contents of the specification, and in order to make the above and other objects, features and advantages of this disclosure more obvious and understandable, specific embodiments of this disclosure are given below. Attached Figure Description
[0017] It should be noted that the accompanying drawings are for illustrative purposes only and should not be considered as limiting the scope of this disclosure. The drawings are not necessarily drawn to scale, and the dimensions of some features may be exaggerated for clarity. The same reference numerals denote the same parts throughout the drawings. For clarity, the same parts may not be shown in all drawings.
[0018] In the attached diagram:
[0019] Figures 1a-1c A schematic diagram of the structure of a strip-shaped Mach-Zehnder modulator according to some embodiments of the present disclosure is shown;
[0020] Figures 2a-2d A schematic diagram of the structure of a folded Mach-Zehnder modulator according to other embodiments of the present disclosure is shown.
[0021] The reference numerals in the detailed embodiments are as follows:
[0022] 100 Folded Mach-Zehnder Modulation Device
[0023] 1. Input terminal
[0024] 2 Output terminal
[0025] 10 First waveguide arm
[0026] 20 Second waveguide arm
[0027] 30 Optical signal modulation section
[0028] 301 Basic Modulation Section
[0029] 302 In-phase modulation section
[0030] 303 Switching to Transition Section
[0031] 304 Inverting modulation section
[0032] 40 beam splitters
[0033] 50 RF electrodes
[0034] 510 Outer Earth Electrode
[0035] 520 negative signal electrode
[0036] 530 Intermediate ground electrode
[0037] 540 Positive Signal Electrode
[0038] 550 Inner Earth Electrode
[0039] 60 optical combining elements
[0040] U1, U2, U3, U4 First Interval
[0041] D1, D2, D3, D4 Second Interval
[0042] S1 First Modulation Zone
[0043] ST Turning Area
[0044] S2 Second Modulation Region Detailed Implementation
[0045] The embodiments of the technical solutions disclosed herein will now be described in detail with reference to the accompanying drawings. These embodiments are merely illustrative of the technical solutions disclosed herein and are therefore intended to limit the scope of protection of this disclosure.
[0046] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of this disclosure; the terms “comprising” and “having”, and any variations thereof, in the specification, claims and foregoing description of the drawings of this disclosure are intended to cover non-exclusive inclusion.
[0047] In the description of the embodiments of this disclosure, technical terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary or secondary relationship of the indicated technical features. In the description of the embodiments of this disclosure, "a plurality of" means two or more, unless otherwise explicitly defined.
[0048] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this disclosure. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.
[0049] In the description of the embodiments of this disclosure, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship.
[0050] In the description of the embodiments of this disclosure, the term "multiple" refers to two or more (including two), similarly, "multiple groups" refers to two or more (including two groups), and "multiple pieces" refers to two or more (including two pieces).
[0051] In the description of the embodiments of this disclosure, the technical terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of this disclosure and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this disclosure.
[0052] In the description of the embodiments of this disclosure, unless otherwise expressly specified and limited, technical terms such as "installation," "connection," "joining," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of this disclosure according to the specific circumstances.
[0053] This disclosure provides a Mach-Zehnder modulation device that can provide optical bandwidth compensation, particularly optimizing the optical bandwidth compensation effect of the modulator and improving modulation bandwidth and modulation efficiency. The Mach-Zehnder modulation device of this disclosure can be used in electro-optic modulators.
[0054] Example 1
[0055] Figures 1a-1c A schematic diagram of the structure of a strip-shaped Mach-Zehnder modulator 100 according to some embodiments of the present disclosure is shown. (Refer to...) Figure 1a and Figure 1bThe elongated Mach-Zehnder modulation device 100 includes a first modulation region S1 and a second modulation region S2 extending sequentially along the optical signal transmission direction. The elongated Mach-Zehnder modulation device 100 includes a first waveguide arm 10 and a second waveguide arm 20, and an RF electrode 50. The first waveguide arm 10 and the second waveguide arm 20 are arranged sequentially without crossing, and each has an optical signal modulation section 30. The RF electrode 50 includes a plurality of integrally non-crossing strip electrodes 510, 520, 530, 540, and 550, configured to apply an RF voltage to the first waveguide arm 10 and / or the second waveguide arm 20. Along the optical signal transmission direction, the optical signal modulation section 30 sequentially includes an inverting modulation section 304, a non-inverting modulation section 302, and a basic modulation section 301. The inverting modulation section 304 is located in the first modulation region S1, and the basic modulation section 301 is located in the second modulation region S2. The first waveguide arm 10 and the second waveguide arm 20 generate a certain phase difference ΔΦ1 in the basic modulation section 301. The first waveguide arm 10 and the second waveguide arm 20 generate a phase difference ΔΦ2 in the in-phase modulation section 302 that is in phase with the phase difference ΔΦ1 generated in the basic modulation section 301. The first waveguide arm 10 and the second waveguide arm 20 generate a phase difference ΔΦ3 in the out-of-phase modulation section 304 that is out of phase with the phase difference ΔΦ1 generated in the basic modulation section 301.
[0056] Reference Figures 1a-1c In the embodiment shown, the Mach-Zehnder modulation device 100 is a strip-shaped Mach-Zehnder modulation device, including a first modulation region S1 and a second modulation region S2 extending sequentially along the optical signal transmission direction, wherein the in-phase modulation segment 302 is located in the second modulation region S2.
[0057] Along the direction of optical signal transmission, the optical signal in the waveguide arm first passes through the first modulation region S1, and then through the second modulation region S2. Therefore, the region where the first modulation region S1 is located is defined as the "front end" and the region where the second modulation region S2 is located is defined as the "back end".
[0058] If the inverting modulation section 304 is placed at the rear end, since the phase difference ΔΦ3 generated by waveguide arms 10 and 20 in the inverting modulation section 304 is in the opposite direction to the phase difference ΔΦ2 generated in the in-phase modulation section 302, at low frequencies, due to the low RF transmission loss, the phase difference ΔΦ3 can cancel out the phase difference ΔΦ2. In this case, the optical signal is mainly modulated by the basic modulation section 301, while the inverting modulation section 304 only serves as a phase compensation. However, at high frequencies, the RF transmission loss increases along the optical signal transmission direction, leading to a weakening of the modulation electric field strength at the rear end, thereby reducing the compensation effect of the rear electric field on the optical signal.
[0059] This disclosure provides the following advantages by arranging the anti-phase modulation section 304 at the front end, i.e., the first modulation region S1: the phase difference ΔΦ3 generated by the anti-phase modulation section 304 will not decrease in amplitude due to transmission loss, ensuring that the anti-phase modulation section has a better compensation effect on the optical bandwidth, thereby improving the overall performance of the modulator.
[0060] In some embodiments, both the first waveguide arm 10 and the second waveguide arm 20 are made of electro-optic materials, such as lithium niobate, lithium tantalate, or potassium titanium phosphate, etc. The first waveguide arm 10 and the second waveguide arm 20 are arranged sequentially without crossing, which can avoid transmission loss and crosstalk caused by the crossing structure.
[0061] Optionally, in some embodiments, the in-phase modulation segment 302 and the out-of-phase modulation segment 304 are of equal length.
[0062] Reference Figure 1a In the illustrated embodiment, the radio frequency electrode 50 includes an outer ground electrode 510, a negative signal electrode 520, a middle ground electrode 530, a positive signal electrode 540, and an inner ground electrode 550 arranged sequentially without crossing. Alternatively, the order of the negative signal electrode and the positive signal electrode can be interchanged, and this disclosure is not limiting in this regard. It should be understood that adjacent electrodes have different potentials, thus forming a modulation electric field between the electrodes.
[0063] Reference Figure 1a In the illustrated embodiment, the radio frequency electrode 50 includes a first spacing group and a second spacing group between adjacent or spaced adjacent strip electrodes. Specifically, in a direction perpendicular to the optical signal transmission direction, the first spacing group includes first spacings U1 and U2 located above the positive signal electrode 540 and below the negative signal electrode 520, and the second spacing group includes second spacings D1 and D2 located below the positive signal electrode 540 and above the negative signal electrode 520. In the inverting modulation section 304, a first waveguide arm 10 is arranged within the first spacing U1 of the first spacing group, and a second waveguide arm 20 is arranged within the second spacing D2 of the second spacing group. In the basic modulation section 301 and the in-phase modulation section 302, the first waveguide arm 10 is arranged within the second spacing D1 of the second spacing group, and the second waveguide arm 20 is arranged within the first spacing U2 of the first spacing group. In this embodiment, the electric field direction is upward in the first spacings U1 and U2, and downward in the second spacings D1 and D2.
[0064] Alternatively, in the inverting modulation section 304, the first waveguide arm 10 is arranged within the first interval U2 of the first interval group, and the second waveguide arm 20 is arranged within the second interval D1 of the second interval group. In the basic modulation section 301 and the in-phase modulation section 302, the first waveguide arm 10 is arranged within the second interval D2 of the second interval group, and the second waveguide arm 20 is arranged within the first interval U1 of the first interval group. The first and second waveguide arms can also be arranged in other ways; not all possible arrangements will be exhaustive here.
[0065] Reference Figure 1c In the illustrated embodiment, the elongated Mach-Zehnder modulation device 100 further includes a beam splitter 40 and a beam combiner 60. The beam splitter 40 is used to split the input optical signal from the input terminal 1 into two paths, which are then directed to the first waveguide arm 10 and the second waveguide arm 20, respectively. The beam combiner 60 is used to combine the two optical signals from the first waveguide arm 10 and the second waveguide arm 20 and output them to the output terminal 2.
[0066] Example 2
[0067] Figures 2a-2d A schematic diagram of the structure of a folded Mach-Zehnder modulator 100 according to other embodiments of this disclosure is shown. (Refer to...) Figure 2a and Figure 2b The folded Mach-Zehnder modulation device 100 includes a first modulation region S1, a turning region ST, and a second modulation region S2 extending sequentially along the optical signal transmission direction. The turning region ST connects the first modulation region S1 and the second modulation region S2. The folded Mach-Zehnder modulation device 100 includes a first waveguide arm 10 and a second waveguide arm 20, and an RF electrode 50. The first waveguide arm 10 and the second waveguide arm 20 are arranged sequentially without crossing, and each has an optical signal modulation segment 30. The RF electrode 50 includes a plurality of integrally non-crossing strip electrodes 510, 520, 530, 540, and 550, configured to apply an RF voltage to the first waveguide arm 10 and / or the second waveguide arm 20. Along the optical signal transmission direction, the optical signal modulation section 30 sequentially includes an inverting modulation section 304, an in-phase modulation section 302, and a basic modulation section 301. The inverting modulation section 304 is located in the first modulation region S1, and the basic modulation section 301 is located in the second modulation region S2. The first waveguide arm 10 and the second waveguide arm 20 generate a certain phase difference ΔΦ1 in the basic modulation section 301. The first waveguide arm 10 and the second waveguide arm 20 generate a phase difference ΔΦ2 in the in-phase modulation section 302 that is in phase with the phase difference ΔΦ1 generated in the basic modulation section 301. The first waveguide arm 10 and the second waveguide arm 20 generate a phase difference ΔΦ3 in the inverting modulation section 304 that is out of phase with the phase difference ΔΦ1 generated in the basic modulation section 301.
[0068] exist Figures 2a-2dIn the illustrated embodiment, the Mach-Zehnder modulation device 100 is a folded Mach-Zehnder modulation device, including a first modulation region S1, a turning region ST, and a second modulation region S2 extending sequentially along the optical signal transmission direction. The turning region ST connects the first modulation region S1 and the second modulation region S2. The first waveguide arm 10 and the second waveguide arm 20 are folded as a whole and are arranged sequentially without crossing in the turning region ST. The radio frequency electrode 50 includes a plurality of strip electrodes that are folded as a whole and arranged sequentially without crossing.
[0069] Reference Figures 2a-2d The illustrated embodiment, due to its folded design, reduces the length of the waveguide arm compared to the elongated Mach-Zehnder modulator in Embodiment 1. To achieve better device performance, the waveguide arm length can be increased as needed, with minimal impact on the overall device length.
[0070] exist Figures 2a-2d In the illustrated embodiment, both the first waveguide arm 10 and the second waveguide arm 20 are made of electro-optic materials, such as lithium niobate, lithium tantalate, or potassium titanium phosphate. The first waveguide arm 10 and the second waveguide arm 20 are folded as a whole and arranged sequentially without crossing in the turning area ST. This design can avoid transmission loss and crosstalk caused by the crossing structure.
[0071] Optionally, in some embodiments, the in-phase modulation segment 302 and the out-of-phase modulation segment 304 are of equal length.
[0072] Reference Figure 2a In the illustrated embodiment, the radio frequency electrode 50 includes an outer ground electrode 510, a negative signal electrode 520, a middle ground electrode 530, a positive signal electrode 540, and an inner ground electrode 550, which are arranged sequentially without crossing each other and are generally folded in shape. Alternatively, the order of the negative signal electrode and the positive signal electrode can be interchanged, and this disclosure is not limited thereto. It should be understood that adjacent electrodes have different potentials, thus forming a modulation electric field between the electrodes.
[0073] In some embodiments, the radio frequency electrode 50 includes a first spacing group and a second spacing group among a plurality of strip electrodes, which are adjacent or spaced apart from each other. Specifically, in a direction perpendicular to the optical signal transmission direction, the first spacing group includes first spacings U1, U2, U3, and U4 located above the positive signal electrode 540 and below the negative signal electrode 520, and the second spacing group includes second spacings D1, D2, D3, and D4 located below the positive signal electrode 540 and above the negative signal electrode 520. Specifically, in the inverting modulation section 304, the first waveguide arm 10 is arranged within any first spacing of the first spacing group, and the second waveguide arm 20 is arranged within any second spacing of the second spacing group; and in the basic modulation section 301 and the in-phase modulation section 302, the first waveguide arm 10 is arranged within any second spacing of the second spacing group, and the second waveguide arm 20 is arranged within any first spacing of the first spacing group. In this embodiment, the electric field direction is upward in the first intervals U1, U2, U3, and U4, while the electric field direction is downward in the second intervals D1, D2, D3, and D4.
[0074] Alternatively, the first and second waveguide arms can be arranged in the opposite manner to the above: in the inverted modulation section 304, the first waveguide arm 10 is arranged in any second interval of the second interval group, and the second waveguide arm 20 is arranged in any first interval of the first interval group; and in the basic modulation section 301 and the in-phase modulation section 302, the first waveguide arm 10 is arranged in any first interval of the first interval group, and the second waveguide arm 20 is arranged in any second interval of the second interval group.
[0075] Reference Figures 2b-2c In the illustrated embodiment, the in-phase modulation section 302 is located in the first modulation region S1, allowing the optical signal to enter the in-phase modulation section 302 from the out-of-phase modulation section 304, and subsequently enter the basic modulation section via the turning region ST. The optical signal modulation section also includes a switching transition section 303 disposed between the in-phase modulation section 302 and the out-of-phase modulation section 304. In the switching transition section 303, each of the two waveguide arms switches from its original interval to another interval with the opposite electric field direction. Specifically, referring to… Figure 2cThe first waveguide arm 10 switches from the second interval D1 located in the in-phase modulation section 304 via the switching transition section 303 into the first interval U2 located in the in-phase modulation section 302. Subsequently, the first waveguide arm 10 moves from the first interval U2 into the first interval U4 via the turning area. The modulation electric field directions in the first interval U2 and the first interval U4 are the same, meaning that the direction of the electric field at the location of the first waveguide arm 10 does not change after folding through the turning area. Similarly, the second waveguide arm 20 switches from the first interval U1 located in the in-phase modulation section 304 via the switching transition section 303 into the second interval D2 located in the in-phase modulation section 302. Subsequently, the second waveguide arm 20 moves from the second interval D2 into the second interval D4 via the turning area.
[0076] The technical solution of this embodiment includes two features: First, after passing through the switching transition section, the electric field direction of each waveguide arm becomes opposite, and after passing through the turning area, the electric field direction of each waveguide arm remains unchanged; Second, the electric field direction of the first waveguide arm is always opposite to the electric field direction of the second waveguide arm.
[0077] exist Figures 2a-2d In the illustrated embodiment, the first waveguide arm 10 and the second waveguide arm 20 lead the turning of the RF electrode 50. This allows the optical signal to have a shorter transmission distance than the RF signal. Alternatively, the first waveguide arm 10 and the second waveguide arm 20 can also be synchronized with the turning of the RF electrode 50. Or alternatively, the first waveguide arm 10 and the second waveguide arm 20 can also lag behind the turning of the RF electrode 50. The respective turning rates of the waveguide arms and strip electrodes can be configured according to actual needs, thereby adjusting the transmission distances of the optical and RF signals. Given the difference between the propagation speed of the RF signal in the metal electrode and the propagation speed of the optical signal in the waveguide, the beneficial effects of this design are: achieving secondary group velocity matching between the optical and RF signals, maintaining a stable phase relationship between the modulated signal and the light wave in the modulation region, and improving modulation bandwidth and modulation efficiency.
[0078] exist Figures 2a-2d In the illustrated embodiment, the first waveguide arm 10 and the second waveguide arm 20 are concentrically curved in the turning region ST, which facilitates manufacturing and minimizes electrical transmission losses. Of course, this disclosure does not impose specific limitations, and the first waveguide arm 10 and the second waveguide arm 20 can be designed in other shapes in the turning region ST as needed.
[0079] Reference Figure 2dThe illustrated embodiment of the folded Mach-Zehnder modulation device 100 further includes a beam splitter 40 and a beam combiner 60. The beam splitter 40 is used to split the input optical signal from the input terminal 1 into two paths, which are then directed to the first waveguide arm 10 and the second waveguide arm 20, respectively. The beam combiner 60 is used to combine the two optical signals from the first waveguide arm 10 and the second waveguide arm 20 and output them to the output terminal 2.
[0080] This disclosure also provides an electro-optic modulator, including the Mach-Zehnder modulation device 100 in any of the above embodiments.
[0081] In summary, the Mach-Zehnder modulator provided in the embodiments of this disclosure optimizes the optical bandwidth compensation effect of the modulator by setting the inverting modulation section in the first modulation region.
[0082] The Mach-Zehnder modulator provided in a further embodiment of this disclosure employs a folded design, which can significantly reduce the length dimension while meeting device performance requirements, achieving miniaturization and making it easier to integrate into a hardware system. A turning region is provided between the first and second modulation regions. By configuring the respective torsional curvatures of the waveguide arms and strip electrodes, the transmission distance of the optical and radio frequency signals can be adjusted, thereby achieving secondary group velocity matching between the optical and radio frequency signals. This ensures that the phase relationship between the modulated signal and the optical wave remains stable within the modulation region, improving modulation bandwidth and modulation efficiency.
[0083] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this disclosure, and not to limit them. Although this disclosure has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this disclosure, and they should all be covered within the scope of the claims and specification of this disclosure. In particular, as long as there is no structural conflict, the various technical features mentioned in the various embodiments can be combined in any way. This disclosure is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.
Claims
1. A Mach-Zehnder modulation device, comprising a first modulation region and a second modulation region extending sequentially along the optical signal transmission direction; or a first modulation region, a turning region, and a second modulation region extending sequentially along the optical signal transmission direction, wherein the turning region connects the first modulation region and the second modulation region, the Mach-Zehnder modulation device comprising: A first waveguide arm and a second waveguide arm are arranged sequentially without intersection. Both the first and second waveguide arms have optical signal modulation sections. The radio frequency (RF) electrode comprises a plurality of non-intersecting, sequentially arranged strip electrodes, configured to apply an RF voltage to the first waveguide arm and / or the second waveguide arm, wherein... Along the optical signal transmission direction, the optical signal modulation section sequentially includes an inverting modulation section, a co-phase modulation section, and a basic modulation section. The inverting modulation section is located in the first modulation region, and the basic modulation section is located in the second modulation region. The first waveguide arm and the second waveguide arm generate a certain phase difference in the basic modulation section. The first waveguide arm and the second waveguide arm generate a phase difference in the co-phase modulation section that is in phase with the phase difference generated in the basic modulation section. The first waveguide arm and the second waveguide arm generate a phase difference in the inverting modulation section that is out of phase with the phase difference generated in the basic modulation section.
2. The Mach-Zehnder modulation device of claim 1, wherein, The in-phase modulation segment and the out-of-phase modulation segment have equal lengths.
3. The Mach-Zehnder modulation device of claim 1, wherein, The radio frequency electrodes include: an outer ground electrode, a negative signal electrode, a middle ground electrode, a positive signal electrode, and an inner ground electrode arranged in sequence without crossing.
4. The Mach-Zehnder modulation device of claim 3, wherein, The radio frequency electrode includes a first spacing group and a second spacing group among a plurality of strip electrodes, either adjacent or spaced apart from each other. In a direction perpendicular to the optical signal transmission direction, the first spacing group includes a first spacing located above the positive signal electrode and below the negative signal electrode, and the second spacing group includes a second spacing located below the positive signal electrode and above the negative signal electrode. In the inverting modulation section, the first waveguide arm is arranged in any first interval of the first interval group, and the second waveguide arm is arranged in any second interval of the second interval group. In the basic modulation section and the in-phase modulation section, the first waveguide arm is arranged in any second interval of the second interval group, and the second waveguide arm is arranged in any first interval of the first interval group.
5. The Mach-Zehnder modulation device according to any one of claims 1 to 4, characterized in that The Mach-Zehnder modulation device is a strip-shaped Mach-Zehnder modulation device, including a first modulation region and a second modulation region extending sequentially along the optical signal transmission direction, wherein the in-phase modulation segment is located in the second modulation region.
6. The Mach-Zehnder modulation device according to any one of claims 1 to 4, characterized in that The Mach-Zehnder modulation device is a folded Mach-Zehnder modulation device, including a first modulation region, a turning region and a second modulation region extending sequentially along the optical signal transmission direction. The turning region connects the first modulation region and the second modulation region. The first waveguide arm and the second waveguide arm are folded as a whole and are arranged sequentially without crossing in the turning region. The radio frequency electrode includes a plurality of strip electrodes that are folded as a whole and arranged sequentially without crossing.
7. The Mach-Zehnder modulation device of claim 6, wherein, The in-phase modulation section is located in the first modulation region, such that the optical signal enters the in-phase modulation section from the out-of-phase modulation section and then enters the basic modulation section via the turning region.
8. The Mach-Zehnder modulation device of claim 6, wherein, The first waveguide arm and the second waveguide arm turn synchronously with the turning of the radio frequency electrode; or the first waveguide arm and the second waveguide arm lag behind the turning of the radio frequency electrode; or the first waveguide arm and the second waveguide arm lead the turning of the radio frequency electrode.
9. The Mach-Zehnder modulation device according to any one of claims 1 to 4, characterized in that The Mach-Zehnder modulation device also includes: A beam splitter element is used to split the input optical signal into two paths, which are then respectively fed into the first waveguide arm and the second waveguide arm; and The optical combining element is used to combine two optical signals from the first waveguide arm and the second waveguide arm and output them.
10. An electro-optic modulator, characterized by The electro-optic modulator includes a Mach-Zehnder modulation device according to any one of claims 1 to 9.