Electro-optic modulator and optical quantum computer
By arranging the input and output optical waveguides in parallel in the electro-optic modulator and using the bent waveguide to reverse the direction of the optical signal, combined with DC bias and RF modulation, the problems of optical crosstalk and increased chip length are solved, achieving smaller size, higher integration and better optical signal transmission effect.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- TURINGQ CO LTD
- Filing Date
- 2025-09-26
- Publication Date
- 2026-06-23
AI Technical Summary
Existing electro-optic modulators use a side-to-side coupling method between the input and output optical ports, which increases optical crosstalk. Furthermore, the entry of radio frequency from the top or bottom side increases the chip length, making it difficult to achieve consistent multi-channel modulation performance.
The input and output optical waveguides are arranged in parallel, and the optical signal direction is reversed by bending the waveguide. Combined with DC bias and RF modulation structure, a loop structure is formed to achieve same-side coupling of input and output optical ports, reduce optical crosstalk, and improve extinction ratio.
This results in a smaller overall size and higher degree of integration for the electro-optic modulator, avoids optical crosstalk, improves the optical signal transmission effect, and ensures the consistency of modulation performance of the multi-channel structure.
Smart Images
Figure CN120972434B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of electro-optic modulation technology, and more specifically, to an electro-optic modulator and an optical quantum computer. Background Technology
[0002] Electro-optic modulators are key devices that utilize the electro-optic effect to modulate optical signals, and they have important applications in fields such as optical fiber communication and microwave optical fiber link technology. Current technologies employ a side-coupled input and output optical port method, where the input light directly reaches the output port, increasing optical crosstalk. Simultaneously, the radio frequency (RF) input from the top or bottom, along with multiple components such as bias electrodes and fiber protection structures placed on the chip, leads to a significant increase in the overall chip length. Summary of the Invention
[0003] The purpose of this invention is to provide an electro-optic modulator and an optical quantum computer that can achieve same-side coupling of input and output optical ports, resulting in a smaller overall size, higher integration, and the ability to avoid direct light from the input port to the output port, thereby reducing optical crosstalk, improving the extinction ratio, and thus improving the optical signal transmission effect.
[0004] In a first aspect, the present invention provides an electro-optic modulator, comprising:
[0005] A waveguide optical path structure includes an input waveguide, a splitting waveguide, a first modulation arm, a second modulation arm, a beam combiner waveguide, a curved waveguide, and an output waveguide. The input waveguide is connected to the input end of the splitting waveguide. The two output ends of the splitting waveguide are respectively connected to one end of the first modulation arm and the second modulation arm. The two input ends of the beam combiner waveguide are respectively connected to the other ends of the first modulation arm and the second modulation arm. The output end of the beam combiner waveguide is connected to the curved waveguide. The output waveguide is arranged parallel to the input waveguide and is connected to the curved waveguide.
[0006] A DC bias structure is provided on both sides of the first modulation arm to perform phase modulation on the optical signal of the first modulation arm.
[0007] A radio frequency modulation structure is provided, which is disposed on both sides of the first modulation arm and both sides of the second modulation arm, for high-speed modulation of the optical signals of the first modulation arm and the second modulation arm.
[0008] The optical signals in the input waveguide and the output waveguide are in opposite directions.
[0009] In an optional embodiment, the electro-optic modulator further includes an input end-face coupler and an output end-face coupler. The input end-face coupler is correspondingly connected to the input end optical waveguide for introducing optical signals, and the output end-face coupler is correspondingly connected to the output end optical waveguide for outputting optical signals. The input end-face coupler and the output end-face coupler are located on the same side of the waveguide optical path structure.
[0010] In optional embodiments, the beam splitter waveguide is an MMI structure, a Y-branch waveguide, or a DC coupler; and / or, the beam combiner waveguide is an MMI structure, a Y-branch waveguide, or a DC coupler.
[0011] In an optional implementation, the bent waveguide comprises two sequentially connected 90-degree bent structures.
[0012] In an optional embodiment, the 90-degree curved structure includes two wedge-shaped coupling portions disposed on the bottom transmission waveguide, the bottom transmission waveguide being in the shape of a quarter arc, and the two wedge-shaped coupling portions being disposed at both ends of the bottom transmission waveguide.
[0013] In an optional embodiment, a shallow etched groove is formed between the two wedge-shaped coupling portions, and a coupling tip is formed at one end of the wedge-shaped coupling portion facing the shallow etched groove, the width of the coupling tip gradually decreasing along the direction toward the shallow etched groove.
[0014] In an optional embodiment, there are multiple waveguide optical path structures, which are stacked sequentially. Multiple first modulation arms, multiple second modulation arms, and multiple output optical waveguides are parallel to each other. Multiple curved waveguides are stacked sequentially. The DC bias structure is arranged close to both sides of each first modulation arm. The radio frequency modulation structure is arranged on both sides of each first modulation arm and each second modulation arm.
[0015] In an optional embodiment, there are multiple waveguide optical path structures, which are symmetrically arranged. The multiple first modulation arms, multiple second modulation arms, and multiple output optical waveguides are parallel to each other. The multiple curved waveguides are arranged symmetrically in pairs. The DC bias structure is arranged close to both sides of each first modulation arm, and the radio frequency modulation structure is arranged on both sides of each first modulation arm and each second modulation arm.
[0016] In an optional embodiment, the radio frequency modulation structure includes a first electrode region, a second electrode region, and a third electrode region that are sequentially spaced apart. The first modulation arm is disposed between the first electrode region and the second electrode region, and the second modulation arm is disposed between the second electrode region and the third electrode region. The DC bias structure is disposed at one end of the first modulation arm near the beam splitter and corresponds to the first electrode region and the second electrode region. A plurality of first microstructures are disposed on the opposite side of the first electrode region and the second electrode region, and the plurality of first microstructures are disposed opposite to each other on both sides of the first modulation arm. A plurality of second microstructures are disposed on the opposite side of the second electrode region and the third electrode region, and the plurality of second microstructures are disposed opposite to each other on both sides of the second modulation arm.
[0017] Secondly, embodiments of the present invention provide an optical quantum computer, including a single-photon source, an optical quantum chip, and a single-photon detector. The optical quantum chip includes the aforementioned electro-optic modulator. The single-photon source is used to generate single photons. The optical quantum chip is used to control the single photons. The single-photon detector is used to measure the single photons and output calculation results.
[0018] The beneficial effects of the embodiments of the present invention include:
[0019] The electro-optic modulator and optical quantum computer provided in this invention embodiment have a waveguide optical path structure on the chip. The input optical waveguide of this waveguide optical path structure is connected to the input end of the splitting waveguide. The two output ends of the splitting waveguide are respectively connected to one end of the first modulation arm and the second modulation arm. The two input ends of the combining waveguide are respectively connected to the other ends of the first modulation arm and the second modulation arm. The output end of the combining waveguide is connected to the curved waveguide. The output optical waveguide and the input optical waveguide are arranged side by side and connected to the curved waveguide. Multiple DC bias structures are correspondingly arranged on both sides of multiple first modulation arms for phase modulation of the optical signals of the first modulation arms. Multiple radio frequency modulation structures are correspondingly arranged on both sides of multiple first modulation arms and multiple second modulation arms for high-speed modulation of the optical signals of the first modulation arms and the second modulation arms. The optical signal directions of the input optical waveguide and the output optical waveguide are opposite. Compared to existing technologies, the electro-optic modulator provided in this invention arranges the input and output optical waveguides side-by-side and achieves directional reversal through a bent waveguide, resulting in opposite optical signal directions between the input and output waveguides. Therefore, it enables same-side coupling of the input and output optical ports, resulting in a smaller overall size, higher integration, and avoids direct light input to the output port, reducing optical crosstalk, improving the extinction ratio, and thus enhancing the optical signal transmission effect. Attached Figure Description
[0020] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.
[0021] Figure 1 This is a schematic diagram of the structure of an electro-optic modulator provided in an embodiment of the present invention;
[0022] Figure 2 for Figure 1 A schematic diagram of the structure of a curved waveguide from a first-view perspective;
[0023] Figure 3 for Figure 1 A schematic diagram of the structure of a curved waveguide from a second perspective;
[0024] Figure 4 for Figure 1 A schematic diagram of the structure of a curved waveguide from a third-view perspective;
[0025] Figure 5 This is a schematic diagram of the structure of a second electro-optic modulator provided in an embodiment of the present invention;
[0026] Figure 6 This is a schematic diagram of the structure of the third electro-optic modulator provided in an embodiment of the present invention;
[0027] Figure 7 This is a schematic diagram of the structure of the fourth electro-optic modulator provided in an embodiment of the present invention.
[0028] Icons: 100-Electro-optic modulator; 110-Waveguide optical path structure; 111-Input optical waveguide; 112-Splitter waveguide; 113-First modulation arm; 114-Second modulation arm; 115-Bundling waveguide; 116-Bend waveguide; 117-Output optical waveguide; 118-Bottom layer transmission waveguide; 119-Wedge-shaped coupling; 1191-Shallow etched trench; 130-DC bias structure; 150-RF modulation structure; 151-First electrode region; 152-Second electrode region; 153-Third electrode region; 154-First microstructure; 155-Second microstructure; 170-Input end face coupler; 190-Output end face coupler. Detailed Implementation
[0029] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.
[0030] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.
[0031] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.
[0032] In the description of this invention, it should be noted that if terms such as "upper," "lower," "inner," or "outer" are used to indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship in which the product of this invention is usually placed, 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, and therefore should not be construed as a limitation of this invention.
[0033] Furthermore, the terms "first" and "second" are used only to distinguish descriptions and should not be interpreted as indicating or implying relative importance.
[0034] As disclosed in the background section, existing electro-optic modulators use contralateral coupling on the same side to transmit optical signals, resulting in direct light input to the output optical port and increased optical crosstalk. Simultaneously, the radio frequency (RF) input from the top or bottom, along with multiple components such as bias electrodes and fiber optic protection structures placed on the chip, significantly increases the overall chip length. Furthermore, when using a multi-channel structure, the RF input from the top or bottom leads to poor consistency in the RF structure of the channels, making it difficult to guarantee consistent modulation performance across multiple channels. The multiple bias electrodes and fiber optic protection structures placed on the chip further contribute to the significant increase in overall chip length.
[0035] To address the aforementioned problems, embodiments of the present invention provide an electro-optic modulator. It should be noted that, without conflict, the features in the embodiments of the present invention can be combined with each other.
[0036] See Figure 1The electro-optic modulator 100 provided in this embodiment of the invention can achieve same-side coupling of input and output optical ports, resulting in a smaller overall size, higher integration, and the integration of multi-channel structures. At the same time, it avoids direct light from the input port to the output port, reduces optical crosstalk, and improves the extinction ratio, thereby improving the optical signal transmission effect.
[0037] The electro-optic modulator 100 provided in this embodiment of the invention includes a waveguide optical path structure 110, a DC bias structure 130, and a radio frequency modulation structure 150. The waveguide optical path structure 110 includes an input optical waveguide 111, a beam splitter waveguide 112, a first modulation arm 113, a second modulation arm 114, a beam combiner waveguide 115, a bent waveguide 116, and an output optical waveguide 117. The input optical waveguide 111 is connected to the input end of the beam splitter waveguide 112. The two output ends of the beam splitter waveguide 112 are respectively connected to one end of the first modulation arm 113 and the second modulation arm 114. The two input ends of the beam combiner waveguide 115 are respectively connected to the first modulation arm 113 and the second modulation arm 114. The other end of the control arm 114 is connected to the output end of the beam combining waveguide 115, which is connected to the bent waveguide 116. The output optical waveguide 117 is arranged in parallel with the input optical waveguide and is connected to the bent waveguide 116. The DC bias structure 130 is correspondingly arranged on both sides of the first modulation arm 113 for phase modulation of the optical signal of the first modulation arm 113. The radio frequency modulation structure 150 is correspondingly arranged on both sides of the first modulation arm 113 and both sides of the multiple second modulation arms 114 for high-speed modulation of the optical signals of the first modulation arm 113 and the second modulation arm 114. The optical signal directions of the input optical waveguide and the output optical waveguide 117 are opposite.
[0038] It should be noted that the multiple waveguide optical path structures 110 constitute a multi-channel structure. The waveguide optical path structures 110 utilize a bent waveguide 116 to form a loop structure. This loop structure ensures that the input and output of the optical signal remain on one side, while the RF input can remain on the opposite side of the modulation arm. This reduces the need for RF bending structures and ensures the consistency of the RF structures between channels; that is, multiple RF modulation structures 150 can maintain consistency. In this embodiment of the invention, the input-end optical waveguide 111 and the output-end optical waveguide 117 are arranged side-by-side, and the direction is reversed through the bent waveguide 116, making the optical signal directions of the input-end optical waveguide and the output-end optical waveguide 117 opposite. Therefore, same-side coupling of the input and output optical ports can be achieved, resulting in a smaller overall size and higher integration. Furthermore, the use of multiple waveguide optical path structures 110 enables the integration of a multi-channel structure. Simultaneously, it avoids direct light input to the output optical port, reducing optical crosstalk, improving the extinction ratio, and thus enhancing the optical signal transmission effect.
[0039] It is worth noting that the electro-optic modulator 100 also includes a substrate wafer, an adhesive film, and a lithium niobate thin film substrate. The lithium niobate thin film substrate is placed above the substrate wafer, the adhesive film is placed between the substrate wafer and the lithium niobate thin film substrate, and multiple waveguide optical path structures 110 are disposed on the lithium niobate thin film substrate. Of course, the basic structure of the electro-optic modulator 100 can be referred to in the existing lithium niobate thin film electro-optic modulator 100.
[0040] In some embodiments, the electro-optic modulator 100 further includes a plurality of input end-face couplers 170 and a plurality of output end-face couplers 190. The plurality of input end-face couplers 170 are correspondingly connected to a plurality of input optical waveguides 111 for introducing optical signals, and the plurality of output end-face couplers 190 are correspondingly connected to a plurality of output optical waveguides 117 for outputting optical signals. The input end-face couplers 170 and the output end-face couplers 190 are located on the same side of the waveguide optical path structure 110. Specifically, the input end-face couplers 170 and the output end-face couplers 190 are both located on the same side of the substrate wafer, thereby enabling same-side light output and input, facilitating connection with external optical fibers.
[0041] In some embodiments, the beam splitter 112 is an MMI structure, a Y-branch waveguide, or a DC coupler; and / or, the beam combiner 115 is an MMI structure, a Y-branch waveguide, or a DC coupler. Preferably, in this embodiment, both the beam splitter 112 and the beam combiner 115 are Y-branch waveguides, which provide better coupling and simpler fabrication.
[0042] In some embodiments, the bent waveguide 116 includes two sequentially connected 90-degree bent structures. Specifically, the two 90-degree bent structures are connected sequentially to achieve a 180° folding of the optical signal, thereby ensuring that the optical signal directions of the input optical waveguide 111 and the output optical waveguide 117 are opposite. Of course, in other preferred embodiments of the present invention, a combination of multiple straight waveguides and multiple bent waveguides 116 at other angles can also be used to achieve the folding of the optical signal, which will not be described in detail here.
[0043] See Figures 2 to 4 Furthermore, the 90-degree curved structure includes a bottom transmission waveguide 118 and two wedge-shaped coupling portions 119 disposed on the bottom transmission waveguide 118. The bottom transmission waveguide 118 is in the shape of a quarter-circular arc, and the two wedge-shaped coupling portions 119 are disposed at both ends of the bottom transmission waveguide 118. The two wedge-shaped coupling portions 119 are respectively an input coupling portion and an output coupling portion. The input coupling portion is connected to the beam combining waveguide 115 and is used to couple the beam-combined optical signal into the bottom transmission waveguide 118 layer. The output coupling portion is connected to the output optical waveguide 117 and is used to lead the optical signal out to the output optical waveguide 117.
[0044] In some embodiments, a shallow etched trench 1191 is formed between the two wedge-shaped coupling portions 119, and a coupling tip is formed at one end of the wedge-shaped coupling portion 119 facing the shallow etched trench 1191. The width of the coupling tip gradually decreases in the direction toward the shallow etched trench 1191. Specifically, the coupling tip of the input coupling portion can couple the optical signal into the underlying transmission waveguide 118, and the coupling tip of the output coupling portion can extract the optical signal from the underlying transmission waveguide 118. By reducing the thickness of the underlying transmission waveguide 118, a single-mode structure can be realized, reducing mode loss.
[0045] In the actual fabrication of the curved waveguide 116, multiple photolithography processes can be employed. First, a waveguide material layer with a curved portion is fabricated using photolithography and etching techniques. The bending angle of this curved portion is determined according to actual requirements (e.g., 90°). Then, the upper waveguide structure is shallowly etched using photolithography to form shallow etched trenches 1191, i.e., the curved portion is etched, thereby forming two coupling tips and shallow etched trenches 1191. Finally, a silicon oxide capping layer is grown at high temperature to complete the fabrication of the curved waveguide 116 structure. Of course, the curved waveguide 116 can also be a multi-layer structure, employing a multi-layer etching method to precisely control the etching height of each layer. The coupling structure is etched on the uppermost waveguide, allowing the optical signal to couple into the lower waveguide without mode change or loss. By controlling the etching height and the width and shape of the curved waveguide 116, the lower waveguide does not undergo mode conversion during bending. After bending, the signal returns to the upper waveguide for transmission through the coupling structure.
[0046] It should be noted that the material of the bent waveguide 116 structure in this embodiment is not limited to lithium niobate, and it can be multiple cascaded bends. The bend can be a functional shape / Eulerian bend. For its shape, please refer to the waveguide bending structure in the prior art.
[0047] See Figure 5 In some embodiments, there are multiple waveguide optical path structures 110, which are stacked sequentially. Multiple first modulation arms 113, multiple second modulation arms 114, and multiple output waveguides 117 are parallel to each other. Multiple curved waveguides 116 are stacked sequentially. A DC bias structure 130 is disposed close to both sides of each first modulation arm 113, and an RF modulation structure 150 is disposed on both sides of each first modulation arm 113 and each second modulation arm 114. Specifically, the output waveguides 117 of the multiple waveguide optical path structures 110 are arranged side-by-side sequentially, while the multiple curved waveguides 116 are stacked in layers along the light-incident direction, and the size of the multiple curved waveguides 116 gradually increases along the light-incident direction.
[0048] It should be noted that in this embodiment, a single waveguide optical path structure 110, a single RF modulation structure 150, and a single DC bias structure 130 can constitute a single channel, that is, a single loop modulation structure. The multiple waveguide optical path structures 110 can be divided into an upper half and a lower half. The upper half includes the input waveguide 111, the splitting waveguide 112, the first modulation arm 113, the second modulation arm 114, and the beam combiner waveguide 115 of the multiple waveguide optical path structures 110. The lower half includes the output waveguide 117 of the multiple waveguide optical path structures 110, and multiple curved waveguides 116 span both the upper and lower half. In a wavelength division multiplexing system, by combining multiple loop modulation structures together, multi-channel wavelength modulation functionality can be achieved.
[0049] See Figure 6 In some embodiments, there are multiple waveguide optical path structures 110, which are symmetrically arranged. Multiple first modulation arms 113, multiple second modulation arms 114, and multiple output waveguides 117 are parallel to each other. Multiple curved waveguides 116 are arranged symmetrically in pairs. A DC bias structure 130 is disposed close to both sides of each first modulation arm 113, and an RF modulation structure 150 is disposed on both sides of each first modulation arm 113 and each second modulation arm 114. Specifically, there is an even number of waveguide optical path structures 110, and the DC bias structures 130 and RF modulation structures 150 are also an even number, with the same quantity as the waveguide optical path structures 110. The waveguide optical path structures 110 can be symmetrically distributed in pairs on the lithium niobate thin film substrate, thereby achieving symmetrical optical path arrangement and enabling multi-channel wavelength modulation functionality.
[0050] See Figure 7 In some embodiments, the radio frequency modulation structure includes a first electrode region 151, a second electrode region 152, and a third electrode region 153 arranged sequentially at intervals. A first modulation arm 113 is disposed between the first electrode region 151 and the second electrode region 152, and a second modulation arm 114 is disposed between the second electrode region 152 and the third electrode region 153. A DC bias structure 130 is disposed at one end of the first modulation arm 113 near the beam splitter 112 and corresponds to the first electrode region 151 and the second electrode region 152. Specifically, the first electrode region 151, the second electrode region 152, and the third electrode region 153 have the same width and are all RF electrodes. Their formation process and materials can refer to those of existing electro-optic modulation structures.
[0051] Furthermore, a plurality of first microstructures 154 are disposed on the opposite side of the first electrode region 151 and the second electrode region 152, and the plurality of first microstructures 154 are disposed opposite to each other on both sides of the first modulation arm 113; a plurality of second microstructures 155 are disposed on the opposite side of the second electrode region 152 and the third electrode region 153, and the plurality of second microstructures 155 are disposed opposite to each other on both sides of the second modulation arm 114. Specifically, the first microstructures 154 are disposed in pairs on both sides of the first modulation arm 113 to form a first control capacitor, and the second microstructures 155 are disposed in pairs on both sides of the second modulation arm 114 to form a second control capacitor. By setting the first microstructures 154 and the second microstructures 155, a control capacitor can be formed in the radio frequency region, increasing the bandwidth and reducing the driving voltage.
[0052] This invention also provides an optical quantum computer, including a single-photon source, an optical quantum chip, and a single-photon detector. The optical quantum chip includes the aforementioned electro-optic modulator. The single-photon source is used to generate single photons, the optical quantum chip is used to control the single photons, and the single-photon detector is used to measure the single photons and output the calculation results.
[0053] In practical applications, the electro-optic modulator provided in this application can be implemented based on basic materials such as lithium niobate and integrated into an optical quantum computer. An optical quantum computer is a quantum computing device that uses photons (light particles) as qubits for information processing. An optical quantum computer mainly includes a single-photon source, an optical quantum chip, and a detection system. The single-photon source generates high-quality single photons as qubit carriers by exciting quantum dots with lasers or by spontaneous parametric down-conversion (SPDC). The optical quantum processor consists of optical components such as optical fibers, waveguides, beam splitters, phase modulators, and mirrors to achieve optical transmission and logical operations (such as Hadamard gates and CNOT gates). The detection system can measure the final state of the photons (such as polarization or path) and output the calculation results. For details on the specific processing procedures of an optical quantum computer, please refer to the specific descriptions of related technologies; they will not be elaborated upon here.
[0054] In summary, the electro-optic modulator 100 and optical quantum computer provided in this embodiment of the invention have a waveguide optical path structure 110 on the chip. The input end of the waveguide optical path structure 110 is connected to the input end of the beam splitter waveguide 112. The two output ends of the beam splitter waveguide 112 are respectively connected to one end of the first modulation arm 113 and the second modulation arm 114. The two input ends of the beam combiner waveguide 115 are respectively connected to the other ends of the first modulation arm 113 and the second modulation arm 114. The output end of the beam combiner waveguide 115 is connected to the curved waveguide 116. Optical waveguide 117 is arranged side-by-side with the input optical waveguide and connected to the bent waveguide 116. Multiple DC bias structures 130 are correspondingly arranged on both sides of multiple first modulation arms 113 for phase modulation of the optical signals of the first modulation arms 113. Multiple radio frequency modulation structures 150 are correspondingly arranged on both sides of the multiple first modulation arms 113 and on both sides of the multiple second modulation arms 114 for high-speed modulation of the optical signals of the first modulation arms 113 and the second modulation arms 114. The optical signals of the input optical waveguide and the output optical waveguide 117 have opposite directions. Compared to the prior art, the electro-optic modulator 100 provided in this embodiment of the invention arranges the input optical waveguide 111 and the output optical waveguide 117 side-by-side and achieves a direction change through the bent waveguide 116, making the optical signal directions of the input optical waveguide and the output optical waveguide 117 opposite. Therefore, it can achieve same-side coupling of the input and output optical ports, resulting in a smaller overall size and higher integration. Furthermore, by employing multiple waveguide optical path structures 110, it can achieve the integration of multi-channel structures. At the same time, it avoids direct light from the input port to the output port, reduces optical crosstalk, and improves the extinction ratio, thereby improving the optical signal transmission effect.
[0055] The above are merely specific embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.
Claims
1. An electro-optic modulator, characterized by include: At least one waveguide optical path structure, each waveguide optical path structure including an input waveguide, a splitting waveguide, a first modulation arm, a second modulation arm, a beam combiner waveguide, a curved waveguide, and an output waveguide, wherein the input waveguide is connected to the input end of the splitting waveguide, the two output ends of the splitting waveguide are respectively connected to one end of the first modulation arm and the second modulation arm, the two input ends of the beam combiner waveguide are respectively connected to the other end of the first modulation arm and the second modulation arm, the output end of the beam combiner waveguide is connected to the curved waveguide, and the output waveguide is arranged in parallel with the input waveguide and connected to the curved waveguide; A DC bias structure is provided on both sides of the first modulation arm to perform phase modulation on the optical signal of the first modulation arm. A radio frequency modulation structure is provided, which is disposed on both sides of the first modulation arm and both sides of the second modulation arm, for high-speed modulation of the optical signals of the first modulation arm and the second modulation arm. The optical signals in the input waveguide and the output waveguide are in opposite directions. The curved waveguide includes two sequentially connected 90-degree curved structures; the 90-degree curved structure includes a bottom transmission waveguide and two wedge-shaped coupling portions disposed on the bottom transmission waveguide, the bottom transmission waveguide is in the shape of a 1 / 4 arc, and the two wedge-shaped coupling portions are disposed at both ends of the bottom transmission waveguide; A shallow etched groove is formed between the two wedge-shaped coupling portions, and a coupling tip is formed at one end of the wedge-shaped coupling portion facing the shallow etched groove, the width of the coupling tip gradually decreasing in the direction toward the shallow etched groove.
2. The electro-optic modulator of claim 1, wherein, The electro-optic modulator further includes an input end-face coupler and an output end-face coupler. The input end-face coupler is connected to the input end optical waveguide for introducing optical signals, and the output end-face coupler is connected to the output end optical waveguide for outputting optical signals. The input end-face coupler and the output end-face coupler are located on the same side of the waveguide optical path structure.
3. The electro-optic modulator of claim 1, wherein, The beam splitter waveguide is an MMI structure, a Y-branch waveguide, or a DC coupler; and / or, the beam combiner waveguide is an MMI structure, a Y-branch waveguide, or a DC coupler.
4. The electro-optic modulator of claim 1, wherein, The waveguide optical path structure comprises multiple structures, which are stacked sequentially. Multiple first modulation arms, multiple second modulation arms, and multiple output optical waveguides are parallel to each other. Multiple curved waveguides are stacked sequentially. The DC bias structure is arranged close to both sides of each first modulation arm. The radio frequency modulation structure is arranged on both sides of each first modulation arm and each second modulation arm.
5. The electro-optic modulator of claim 1, wherein, The waveguide optical path structure comprises multiple waveguide optical path structures, which are symmetrically arranged. Multiple first modulation arms, multiple second modulation arms, and multiple output optical waveguides are parallel to each other. Multiple curved waveguides are arranged symmetrically in pairs. The DC bias structure is arranged close to both sides of each first modulation arm, and the radio frequency modulation structure is arranged on both sides of each first modulation arm and each second modulation arm.
6. The electro-optic modulator of claim 1, wherein, The radio frequency modulation structure includes a first electrode region, a second electrode region, and a third electrode region that are sequentially spaced apart. The first modulation arm is disposed between the first electrode region and the second electrode region, and the second modulation arm is disposed between the second electrode region and the third electrode region. The DC bias structure is disposed at one end of the first modulation arm near the beam splitter and corresponds to the first electrode region and the second electrode region. A plurality of first microstructures are disposed on the opposite side of the first electrode region and the second electrode region, and the plurality of first microstructures are disposed opposite to each other on both sides of the first modulation arm. A plurality of second microstructures are disposed on the opposite side of the second electrode region and the third electrode region, and the plurality of second microstructures are disposed opposite to each other on both sides of the second modulation arm.
7. A photonic quantum computer, characterized by The device includes a single-photon source, a quantum chip, and a single-photon detector. The quantum chip includes an electro-optic modulator as described in any one of claims 1-6. The single-photon source is used to generate single photons. The quantum chip is used to control the single photons. The single-photon detector is used to measure the single photons and output calculation results.