A high-order mode based reflective integrated optical resonant structure

Abstract

The application discloses a reflection type integrated optical resonant structure based on high-order modes, which comprises a first single-mode optical waveguide, a multimode optical waveguide, a first mode coupler, at least one optical phase shifter and a multimode conversion optical reflection module. Two single-mode ports of the first mode coupler are connected with the first single-mode optical waveguide respectively. The multimode port of the first mode coupler is connected with the optical phase shifter through the multimode optical waveguide. Or the multimode port of the first mode coupler is connected with the optical phase shifter and the multimode conversion optical reflection module through the multimode optical waveguide. The multimode conversion optical reflection module is used for changing the mode channel of the light in the incident multimode optical waveguide, so that the light is reversely propagated through another mode channel. The application does not need to bend the waveguide to form a loop, so that the design of the resonant length is more flexible, a larger free spectral range can be realized, the utilization rate of the optical field energy of the resonator is improved, and high-efficiency optical modulation of the optical resonant structure is realized.

Description

Technical Field

[0001] This invention belongs to the field of optical communication and integrated optics technology, specifically relating to a reflective integrated optical resonant structure based on higher-order modes. Background Technology

[0002] In on-chip integrated photonics, optical resonant structures have significant applications in wavelength division multiplexing, optical routing, and optical modulation. Traditional structures for realizing on-chip optical resonators mainly include micro-ring (MR) structures and Fabry-Perot (FP) resonant structures. MR structures require control over the total length of the ring to match the requirements of the free spectral range (FSR), but their total length is affected by factors such as the coupling length and bending length, requiring comprehensive consideration and thus limiting their design. FP coupling structures utilize directional couplers and optical reflectors for coupling, avoiding the influence of bending length on the total length found in MR structures. However, due to the bidirectional nature of the directional coupler, FPs exhibit a reverse optical field output at the input waveguide, increasing insertion loss during overall device application. Summary of the Invention

[0003] To address the aforementioned problems in the prior art, this invention provides a reflective integrated optical resonator structure based on a higher-order mode. The technical problem to be solved by this invention is achieved through the following technical solution:

[0004] A high-order mode-based reflective integrated optical resonant structure includes: a first single-mode optical waveguide, a multimode optical waveguide, a first mode coupler, at least one optical phase shifter, and a multimode conversion optical reflection module;

[0005] The two single-mode ports of the first mode coupler are respectively connected to the first single-mode optical waveguide, and the ends of the two first single-mode optical waveguides serve as the input port and output port of the reflective integrated optical resonant structure, respectively.

[0006] The multimode port of the first mode coupler is connected to the optical phase shifter through the multimode optical waveguide; or the multimode port of the first mode coupler is connected to the optical phase shifter and the multimode conversion optical reflection module through the multimode optical waveguide.

[0007] The multimode conversion optical reflection module is used to reflect the light incident in the multimode optical waveguide back into the multimode optical waveguide and realize the reverse propagation of the optical field. It is also used to change the mode channel of the light incident in the multimode optical waveguide so that it propagates in reverse through another mode channel.

[0008] In one embodiment of the present invention, the multimode conversion optical reflection module has the same or similar reflectivity in its wavelength dimension for different modes within the operating wavelength range.

[0009] In one embodiment of the present invention, the multimode conversion optical reflection module includes: two multimode conversion optical reflectors;

[0010] Each of the multimode converter optical reflectors has multiple different mode channels; the number of mode channels is an even number.

[0011] Two mode channels constitute a mode conversion channel group, and the mode of light incident on the multimode optical waveguide of the multimode conversion optical reflector is converted between the two mode channels within the incident mode conversion channel group.

[0012] Each of the multimode conversion optical reflectors has at least one mode conversion channel group;

[0013] In this process, light emitted from one multimode conversion optical reflector in the multimode optical waveguide is incident on another multimode conversion optical reflector for mode conversion.

[0014] In one embodiment of the present invention, when the number of light modes N = 2, the number of mode channels is two, forming a mode conversion channel group.

[0015] In one embodiment of the present invention, when the number of light modes N > 2, the mode conversion channel groups of the two multimode conversion optical reflectors are different, and the mode conversion channels between the two multimode conversion optical reflectors are complementary so that the light field incident on the multimode conversion optical reflector can traverse all mode conversion channels.

[0016] In one embodiment of the present invention, there are multiple optical phase shifters, and the multiple optical phase shifters located between the multimode port and the multimode conversion optical reflector are connected in series.

[0017] In one embodiment of the present invention, a second mode coupler and a second single-mode optical waveguide are also included;

[0018] One multimode port of the second mode coupler is connected to the multimode port of the first mode coupler located on the output port side of the reflective integrated optical resonant structure; the other multimode port of the second mode coupler is connected to the multimode optical waveguide on the output port side of the reflective integrated optical resonant structure.

[0019] The second mode coupler is located on the single-mode port of the output port and is connected to the second single-mode optical waveguide.

[0020] The beneficial effects of this invention are:

[0021] This invention utilizes higher-order modes to provide mode channels for the circulation and resonance of light waves. A multimode converter optical reflector enables the switching of the optical field between different mode channels and resonates with the mode coupler. It eliminates the need for the bent waveguide in MR resonant structures and avoids the reverse light output found in FP resonant structures. Furthermore, it significantly improves the phase shift efficiency of the optical phase shifter, achieving high-efficiency optical modulation of the optical resonant structure.

[0022] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0023] Figure 1 A schematic diagram of a reflective integrated optical resonator structure based on a higher-order mode provided in an embodiment of the present invention;

[0024] Figure 2 A schematic diagram of the mode channel grouping of a six-mode channel of a reflective integrated optical resonator structure based on a higher-order mode, provided for an embodiment of the present invention;

[0025] Figure 3 A schematic diagram of optical field transmission between two multimode conversion optical reflectors under six-mode channels provided in an embodiment of the present invention;

[0026] Figure 4 A schematic diagram of another reflective integrated optical resonator structure based on a higher-order mode provided in an embodiment of the present invention.

[0027] Explanation of reference numerals in the attached figures:

[0028] 10 - First single-mode optical waveguide; 20 - Multimode optical waveguide; 30 - First mode coupler; 40 - Optical phase shifter; 51 - Multimode conversion optical reflector; 60 - Second mode coupler; 70 - Second single-mode optical waveguide. Detailed Implementation

[0029] The present invention will be further described in detail below with reference to specific embodiments, but the implementation of the present invention is not limited thereto.

[0030] Example 1

[0031] A high-order mode-based reflective integrated optical resonant structure includes: a first single-mode optical waveguide 10, a multimode optical waveguide 20, a first mode coupler 30, at least one optical phase shifter 40, and a multimode conversion optical reflection module.

[0032] The first mode coupler 30 is used to couple the fundamental mode of the input single-mode optical waveguide to one of the multiple mode channels of the multimode optical waveguide 20, without interacting with other channels in terms of energy and information, i.e., it has mode selectivity. The first mode coupler 30 includes two single-mode ports and two multimode ports. The two single-mode ports of the first mode coupler 30 are respectively connected to the first single-mode optical waveguide 10, and the ends of the two first single-mode optical waveguides 10 serve as the input port and output port of the reflective integrated optical resonant structure, respectively.

[0033] The multimode port of the first mode coupler 30 is connected to the optical phase shifter 40 through the multimode optical waveguide 20; or the multimode port of the first mode coupler 30 is connected to the optical phase shifter 40 and the multimode conversion optical reflection module through the multimode optical waveguide 20.

[0034] The multimode conversion optical reflection module is used to reflect the light in the incident multimode optical waveguide 20 back into the multimode optical waveguide 20 and realize the reverse propagation of the optical field. It is also used to change the mode channel of the light in the incident multimode optical waveguide 20 so that it can propagate in reverse through another mode channel.

[0035] In this embodiment, the optical field repeatedly passes through the multimode waveguide 20, and therefore repeatedly through the optical phase shifter 40. When the number of modes traversed by the optical field is N, it will pass through the optical phase shifter 40 N times, thus increasing the modulation efficiency by N times. Compared to the MR resonator, the reflective resonance achieved by the multimode conversion optical reflection module in this embodiment, which realizes the switching of the optical field between different mode channels and forms resonance with the mode coupler, does not require bending the waveguide to form a loop. Therefore, the design of its resonance length is more flexible, which is conducive to achieving a larger free spectral region. Compared to the FP resonator, the resonant structure in this embodiment utilizes the traversal of the optical field through higher-order modes and the selectivity of the mode coupler for higher-order modes to avoid the optical field emanating from the input end of the resonator, thereby improving the resonator's utilization rate of optical field energy.

[0036] Optionally, the reflective integrated optical resonator structure in this embodiment can be based on a silicon-based photonics platform, an indium phosphide optical device platform, or a thin-film lithium niobate integrated optical device platform, etc.

[0037] Optionally, the single-mode optical waveguide and multi-mode optical waveguide 20 can be single-mode strip waveguides, ridge waveguides, or slot waveguides commonly found in integrated photonic devices, or polymer waveguides.

[0038] Optionally, the first mode coupler 30 can be a bidirectional router based on an asymmetric directional coupler or a mode switch designed in reverse.

[0039] Optionally, the coupling efficiency of the mode coupler can be greater than 0 and less than 100%, in which case the optical field resonates and the device can function as a resonator; or it can be 100%, in which case the optical field does not resonate and the device as a whole can function as a high-efficiency phase shifter. The function of the optical phase shifter 40 is to phase shift the passing optical field.

[0040] Optionally, the optical phase shifter 40 can be a phase modulator based on electro-optic or thermo-optic effects. The function of the multimode conversion optical reflector 51 in the multimode conversion optical reflection module is to change the mode channel of the incident multimode waveguide, causing it to propagate in the opposite direction through another mode channel.

[0041] Optionally, the multimode conversion optical reflector 51 of the multimode conversion optical reflector module can be an ultra-compact silicon-based photonics multimode conversion optical reflector 51 based on reverse design, or it can be a multimode conversion optical reflector 51 based on a mode multiplexer / demultiplexer and a multimode interference coupler loop.

[0042] Example 2

[0043] like Figure 1 As shown, based on Embodiment 1, this embodiment further defines a multimode conversion optical reflection module, including: two multimode conversion optical reflectors 51; the multimode conversion optical reflectors 51 have broadband characteristics for multiple modes, that is, within the operating wavelength range, they have the same or similar reflection characteristics (reflectivity) for different mode wavelength dimensions. Each multimode port of the first mode coupler 30 can connect to zero to at least one optical phase shifter 40. That is, when the number of optical phase shifters 40 is one, one multimode port is not connected to an optical phase shifter 40, but is connected to one multimode conversion optical reflector 51 through a multimode optical waveguide 20; the other multimode port is connected to one optical phase shifter 40 through the multimode optical waveguide 20, and the optical phase shifter 40 is connected to another multimode conversion optical reflector 51 through the multimode optical waveguide 20. When there are multiple optical phase shifters 40, there are two connection methods. One is that one multimode port is not connected to an optical phase shifter 40, but is connected to a multimode conversion optical reflector 51 through a multimode optical waveguide 20. Another multimode port is connected to multiple optical phase shifters 40 in series through a multimode optical waveguide 20, and the optical phase shifter 40 at the end is connected to another multimode conversion optical reflector 51 through a multimode optical waveguide 20. The other is that each multimode port is connected to multiple optical phase shifters 40 in series through a multimode optical waveguide 20, and the two optical phase shifters 40 at the end are connected to two multimode conversion optical reflectors 51 through a multimode optical waveguide 20 respectively.

[0044] Furthermore, the multimode conversion optical reflector 51 simultaneously supports multiple optical waveguide modes (denoted as N), and each multimode conversion optical reflector 51 has multiple (N) different mode channels; the number of mode channels N is an even number. Two multimode conversion optical reflectors 51 have identical mode channels. Two mode channels constitute a mode conversion channel group. The mode of light incident on the multimode optical waveguide 20 of the multimode conversion optical reflector 51 is converted between the two mode channels within its incident mode conversion channel group. That is, any two mode channels can constitute a mode conversion channel group, and the mode of the optical field can be converted between the mode channels within its mode conversion channel group, that is, the propagation mode of the incident light field is transformed into another mode within the group, and then propagates in the reverse direction through the multimode optical waveguide 20.

[0045] Each multimode conversion optical reflector 51 has at least one mode conversion channel group; wherein, light emitted from one multimode conversion optical reflector 51 in a multimode optical waveguide 20 is incident on another multimode conversion optical reflector 51 for mode conversion. Since the mode channels of the two multimode conversion optical reflectors 51 are the same, the light field emitted from multimode conversion optical reflector 1, after entering multimode conversion optical reflector 2, must belong to one of the multiple mode channels in multimode conversion optical reflector 2, thus undergoing mode conversion to another mode within the group. Then, after propagating in the reverse direction through multimode optical waveguide 20, it re-enters multimode conversion optical reflector 1, and must also belong to one of the multiple mode channels in multimode conversion optical reflector 1, thus undergoing conversion to another mode within the group. In this way, the light propagates back and forth between the two multimode conversion optical reflectors 51 and passes through all mode channels, finally returning to the mode output by the first mode coupler 30 after coupling the fundamental mode single-mode optical waveguide to the multimode optical waveguide 20. Based on this, the optical phase shifter 40 is passed through multiple times, thereby improving the modulation efficiency of the optical phase shift. The optical field of any specific mode in the multimode optical waveguide 20 will only propagate in one direction, so that no multimode corresponding to the mode coupler will enter the mode coupler in reverse (that is, it will not enter the first mode coupler 30 from port d in reverse and be output to port a), so that no optical energy will leak from the input end, increasing the utilization rate of the resonator for the optical field energy.

[0046] The optical field enters the first mode coupler 30 from the single-mode waveguide at the input port a in the fundamental mode. After being coupled by the first mode coupler 30, it becomes any mode in the multimode waveguide 20. It then exits from the multimode port d through the multimode waveguide 20. After passing through the multimode conversion reflector 51, the optical field is converted to another mode channel for reverse transmission. When it passes through the first mode coupler 30 again, due to the mode selectivity of the first mode coupler 30, the optical field directly passes through the first mode coupler 30 to another multimode port c. After being transmitted to the other side of the multimode conversion reflector 51, it is converted to another mode channel again for reverse transmission back to the first mode coupler 30, and so on. During the transmission process in the multimode waveguide 20, it passes through the optical phase shifter 40.

[0047] In one feasible implementation, when the number of modes N = 2, the number of mode channels is two, and the two different mode channels constitute a mode conversion channel group. At this time, the two multimode conversion optical reflectors 51 are identical, and the mode conversion channel groups of the two multimode conversion optical reflectors 51 are identical.

[0048] In one feasible implementation, when the number of modes N > 2, the mode conversion channel groups of the two multimode conversion optical reflectors 51 are different. In this case, each mode conversion channel group of the two multimode conversion optical reflectors 51 is different; that is, the two mode channels of the mode conversion channel group in multimode conversion optical reflector 1 are located in two different mode conversion channel groups in multimode conversion optical reflector 2, meaning the mode channel groups of the two multimode conversion optical reflectors 51 are different.

[0049] Specifically, the multimode conversion optical reflector 51 supports N modes (N = 2m, which is an even number). The mode pair selection of the two multimode conversion optical reflectors 51 that form the high-order mode reflective integrated optical resonant structure has the following characteristics:

[0050] 1) Group the N=2m mode channels of each multimode conversion optical reflector 51 into pairs to form m mode conversion channel groups. Therefore, the mode of the incident light field must belong to one of the m mode conversion channel groups. The incident light field will be reflected and propagated in the opposite direction along the incident multimode optical waveguide 20. Its waveguide mode is changed to another mode of the mode conversion channel group.

[0051] 2) Considering the N mode channels as N nodes in graph theory, connecting two modes in the mode conversion channel group of each multimode converter 51 results in m independent connections (solid lines) from multimode converter 1 and m connections (dashed lines) from multimode converter 2. The mode channels at the ends of the solid and dashed lines form a group, and the connections of the 2m mode conversion channel groups from the two multimode converters are complementary, forming a cycle in graph theory. Complementarity means that the light field incident on the multimode converter 51 can traverse all mode conversion channels during reflection between the two multimode converters 51, i.e., the incident light field can form mode traversal.

[0052] For example, such as Figure 2 The diagram illustrates the arrangement of mode conversion channel groups for two multimode converting optical reflectors 51 in six modes. Multimode converting optical reflector 1 has six mode channels: A, B, C, D, E, and F. B and C form one mode conversion channel group, D and E form another, and F and A form yet another. Multimode converting optical reflector 2 also has six mode channels: A, B, C, D, E, and F. However, its mode conversion channel groups differ from those of multimode converting optical reflector 1: A and B form one group, C and D form another, and E and F form yet another. This means the mode conversion channel groups between the two multimode converting optical reflectors 51 form the aforementioned complementary structure, ensuring that the incident light field traverses all mode conversion channels during reflection between the two multimode converting optical reflectors 51. That is, the optical resonant structure formed by two multimode converters allows the light field to enter from the i-th mode, undergo continuous reflection and mode conversion, traverse N mode channels, and finally return to the i-th mode, as shown below. Figure 3 As shown. Of course, under the condition of complementarity, the six mode channels can be arbitrarily grouped into pairs. For N mode channels, the optical field will pass through each optical phase shifter 40N times, thus increasing the optical modulation efficiency by N times.

[0053] Optionally, the single-mode optical waveguide is a 220nm×450nm silicon strip square waveguide, beneath which is a 2μm buried oxide silicon dioxide layer, and below the buried oxide silicon dioxide layer is a 750μm thick single-crystal silicon substrate. Its function is to guide the light field to propagate on the chip.

[0054] The multimode waveguide 20 is a 220nm×900nm dual-mode silicon waveguide, beneath which is a 2μm buried oxide / silicon dioxide layer, and below that is a 750μm thick single-crystal silicon substrate. Its function is to guide the propagation of TE0 and TE1 mode optical fields within the integrated chip.

[0055] Optionally, the first mode coupler 30 can be a TE0 and TE1 mode multiplexer / demultiplexer based on a silicon-based asymmetric directional coupler, or it can be a silicon-based TE0 and TE1 mode multiplexer / demultiplexer generated through reverse design. Its function is to couple the TE1 mode in the multimode waveguide with the fundamental mode in the single-mode waveguide.

[0056] Optionally, the optical phase shifter 40 can be a multimode optical waveguide 20 covered with a titanium nitride hot electrode, or it can be a doped multimode optical waveguide 20 doped with nitrogen and phosphorus elements. Its function is to change the equivalent refractive index of the waveguide through the thermo-optical effect or plasma dispersion effect of silicon material, thereby changing the phase of the light field after passing through the phase shifter arm.

[0057] For example, the on-chip dual-mode reflective integrated optical resonator structure based on a silicon-based photonics platform has two operating modes:

[0058] (i) The coupling efficiency of the first mode coupler 30 is not 100%. The fundamental mode light field input through the single-mode optical waveguide is partially coupled to the TE1 mode of the multimode optical waveguide 20 through the first mode coupler 30 and output from d. After passing through the optical phase shifter 40, it reaches the multimode conversion optical reflector 51 on the right. It is converted to the TE0 mode by the multimode conversion optical reflector 51 and reflected to the left. When it passes through the first mode coupler 30 again, due to its selective characteristics, it will not be coupled to the single-mode waveguide by the first mode coupler 30. Instead, it will pass directly through the first mode coupler 30 and enter the multimode conversion optical reflector 51 on the left after being output from the multimode waveguide on the right. It will be converted to the TE1 mode and reflected again. At this time, after passing through the first mode coupler 30, part of the light will be coupled to the output waveguide and interfere with the light that was not coupled and passed directly through the first mode coupler 30. The other part of the light will remain in the resonant structure and repeat this process continuously. This is the resonant working mode. Compared to microring resonant structures, the lengths of the coupler and resonant waveguide can be adjusted more flexibly, thus making it suitable for a wider range of needs; compared to Fabry-Perot structures, this structure does not have energy reverse-coupled to the input, resulting in higher energy utilization efficiency.

[0059] (ii) When the coupling efficiency of the first-mode coupler 30 is 100% or very close to 100%, the fundamental mode optical field input through the single-mode optical waveguide is nearly entirely coupled to the TE1 mode of the multimode optical waveguide 20 via the first-mode coupler 30. After passing through the optical phase shifter 40, it reaches the right-side multimode conversion optical reflector 51, where it is nearly entirely converted to the TE0 mode for reverse transmission. When it passes through the first-mode coupler 30 again, due to its selective characteristics, it will not be coupled to the single-mode optical waveguide by the first-mode coupler 30. Instead of passing through the first mode coupler 30, the light field is directly output from the multimode waveguide at the other end and enters the multimode conversion optical reflector 51 on the left. It is then almost entirely converted to TE1 mode and reflected. At this time, after passing through the first mode coupler 30, almost all of the light field will be coupled to the output waveguide. At this time, the input and output light energy will not resonate. However, since the light field has passed through the optical phase shifter 40 multiple times, the effect of the optical phase shifter 40 on the light field is multiplied. The device can be used as a high-efficiency phase modulator or phase shifter. This is the phase shift working mode.

[0060] Example 3

[0061] Based on Embodiment 2, this embodiment further defines a high-order mode-based reflective integrated optical resonant structure, which also includes a second mode coupler 60 and a second single-mode optical waveguide 70.

[0062] One multimode port of the second-mode coupler 60 is connected to the multimode port of the first-mode coupler 30 located on the output port side of the reflective integrated optical resonant structure; the other multimode port of the second-mode coupler 60 is connected to the multimode optical waveguide 20 on the output port side of the reflective integrated optical resonant structure.

[0063] The single-mode port of the second-mode coupler 60, located on one side of the output port, is connected to the second single-mode optical waveguide 70 to serve as another output port. The other single-mode port of the second-mode coupler 60 is not used. The second-mode coupler 60 couples out a portion of the TE1 mode according to the direction of TE1 mode transmission. The spectral form of this other output port is the lower peak of the resonant structure (i.e., bandpass filtering), which can be used for filtering devices such as laser external cavities.

[0064] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., 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 this invention and simplifying the description, and do not 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 this invention.

[0065] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0066] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., 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 this invention according to the specific circumstances.

[0067] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0068] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. In addition, those skilled in the art can combine and integrate the different embodiments or examples described in this specification.

[0069] The above description, in conjunction with specific preferred embodiments, provides a further detailed explanation of the present invention. It should not be construed that the specific implementation of the present invention is limited to these descriptions. For those skilled in the art, various simple deductions or substitutions can be made without departing from the concept of the present invention, and all such modifications and substitutions should be considered within the scope of protection of the present invention.

Claims

1. A reflective integrated optical resonator structure based on higher-order modes, characterized in that, include: The system comprises a first single-mode optical waveguide (10), a multimode optical waveguide (20), a first mode coupler (30), at least one optical phase shifter (40), and a multimode conversion optical reflection module. The two single-mode ports of the first mode coupler (30) are respectively connected to the first single-mode optical waveguide (10), and the ends of the two first single-mode optical waveguides (10) serve as the input port and output port of the reflective integrated optical resonant structure, respectively. The multimode port of the first mode coupler (30) is connected to the optical phase shifter (40) and the multimode conversion optical reflection module through the multimode optical waveguide (20); The multimode conversion optical reflection module is used to reflect the light incident in the multimode optical waveguide (20) back into the multimode optical waveguide (20) and realize the reverse propagation of the optical field. It is also used to change the mode channel of the light incident in the multimode optical waveguide (20) so that it can propagate in reverse through another mode channel. The multimode conversion optical reflection module includes: two multimode conversion optical reflectors (51); each multimode conversion optical reflector (51) has multiple different mode channels; the number of mode channels is even, and the number of mode channels N>2; two mode channels constitute a mode conversion channel group, and the mode of light incident on the multimode optical waveguide (20) of the multimode conversion optical reflector (51) is converted between the two mode channels within the mode conversion channel group; each multimode conversion optical reflector (51) has at least one mode conversion channel group; wherein light emitted from one multimode conversion optical reflector (51) in the multimode optical waveguide (20) is incident on another multimode conversion optical reflector (51) for mode conversion; The two multimode conversion optical reflectors (51) have different mode conversion channel groups, and the mode conversion channels between the two multimode conversion optical reflectors (51) are complementary so that the light field incident on the multimode conversion optical reflector (51) can traverse all mode conversion channels.

2. The reflective integrated optical resonator structure based on a higher-order mode according to claim 1, characterized in that, The multimode conversion optical reflection module has the same or similar reflectivity in its wavelength dimension for different modes within the operating wavelength range.

3. The reflective integrated optical resonator structure based on a higher-order mode according to claim 1, characterized in that, The number of optical phase shifters (40) is multiple, and the multiple optical phase shifters (40) located between the multimode port and the multimode conversion optical reflector (51) are connected in series.

4. The reflective integrated optical resonator structure based on a higher-order mode according to claim 1, characterized in that, It also includes a second-mode coupler (60) and a second single-mode optical waveguide (70); One multimode port of the second mode coupler (60) is connected to the multimode port of the first mode coupler (30) located on the output port side of the reflective integrated optical resonant structure; the other multimode port of the second mode coupler (60) is connected to the multimode optical waveguide (20) on the output port side of the reflective integrated optical resonant structure. The second mode coupler (60) has a single-mode port located on one side of the output port that is connected to the second single-mode optical waveguide (70).

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