High-modulation-efficiency microring modulator

Abstract

The application provides a high-modulation-efficiency micro-ring modulator, comprising: an input waveguide for coupling an optical signal into a micro-ring resonant cavity to output a first optical signal; a first feedback loop waveguide connected with a first mode converter, for mode conversion of the optical signal to output a second optical signal; a second mode converter for mode conversion of the second optical signal to output a third optical signal; a third mode converter for mode conversion of the third optical signal to output a fourth optical signal; a fourth mode converter for mode conversion of the fourth optical signal to output a fifth optical signal; the output of the fourth mode converter is connected with the input of the third mode converter through a second feedback loop waveguide, and the fifth optical signal is sent into an optoelectronic modulation module again for phase modulation. An adjustable micro-ring resonant cavity is used for modulation of the first, second, fourth and fifth optical signals. The optical signal modulated for multiple times is finally coupled to an output waveguide through a second half-ring waveguide and output, so that the modulation efficiency of the whole micro-ring resonant cavity is improved.

Description

Technical Field

[0001] This invention relates to the field of optoelectronic device technology, and more specifically, to a high modulation efficiency micro-ring modulator. Background Technology

[0002] Electro-optic modulators are key devices for converting high-speed electrical signals into the optical domain, and they have wide applications in optical communication, optical sensing, and other fields. In recent years, with the development of integrated optoelectronic technology, integrated electro-optic modulators have been extensively studied and are gradually becoming the main development direction for electro-optic modulators. Structurally, the mainstream electro-optic modulators can be mainly divided into two types: Mach-Zehnder interferometer modulators and micro-ring resonator modulators. Compared with Mach-Zehnder interferometer modulators, micro-ring resonator modulators have advantages such as small size, high modulation efficiency, simple driving circuit, and low power consumption. In recent years, they have attracted increasing attention from researchers.

[0003] To promote the practical application of integrated electro-optic modulators, we need to reduce the driving voltage of integrated modulators as much as possible so that they can modulate optical signals under voltage conditions supported by CMOS integrated circuits. However, even for micro-ring resonator modulators, it is difficult to truly achieve effective modulation of optical signals under CMOS voltages due to the limited change in the refractive index of the material per unit voltage.

[0004] Therefore, it is urgent to propose new device structures and design methods to improve the modulation efficiency of micro-ring modulators and reduce the driving voltage required for normal operation of micro-ring modulators, so as to promote the practical application of micro-ring modulators. Summary of the Invention

[0005] In view of the shortcomings of the prior art, the purpose of this invention is to provide a high modulation efficiency micro-ring modulator.

[0006] A high modulation efficiency microring modulator provided by the present invention includes: an input waveguide, an output waveguide, an adjustable microring resonant cavity, a first feedback loop waveguide, a second feedback loop waveguide, a first mode converter, a second mode converter, a third mode converter, and a fourth mode converter.

[0007] The input waveguide is used to couple the optical signal into the tunable microring resonator. The first mode converter, the second mode converter, the third mode converter, and the fourth mode converter are connected in the tunable microring resonator. The two ends of the first feedback loop waveguide are respectively connected to an input terminal of the first mode converter and an output terminal of the second mode converter. The two ends of the second feedback loop waveguide are respectively connected to an input terminal of the third mode converter and an output terminal of the fourth mode converter. The output waveguide is used to couple the modulated optical signal out of the tunable microring resonator.

[0008] Preferably, the tunable micro-ring resonant cavity includes a first optoelectronic modulation module, a second optoelectronic modulation module, a first half-ring waveguide, and a second half-ring waveguide. The first optoelectronic modulation module and the second optoelectronic modulation module are connected through the first half-ring waveguide and the second half-ring waveguide to form a closed ring resonant cavity with tunable resonant wavelength. The two ends of the first half-ring waveguide are respectively connected to a first mode converter and a fourth mode converter, and the two ends of the second half-ring waveguide are respectively connected to a second mode converter and a third mode converter.

[0009] Preferably, the first optoelectronic modulation module and the second optoelectronic modulation module have the same structure, which is a silicon-based electro-optic modulation module or a silicon-based thermo-optic modulation module based on ion doping. The waveguide refractive index change region in the modulation module increases with the increase of the waveguide width.

[0010] Preferably, the first feedback loop waveguide includes a first semicircular waveguide, a first straight waveguide, and a second semicircular waveguide connected in sequence. The first semicircular waveguide is connected to a first mode converter, and the second semicircular waveguide is connected to a second mode converter.

[0011] Preferably, the second feedback loop waveguide includes a third semicircular waveguide, a second straight waveguide, and a fourth semicircular waveguide connected in sequence. The third semicircular waveguide is connected to a third mode converter, and the fourth semicircular waveguide is connected to a fourth mode converter.

[0012] Preferably, the first mode converter, the second mode converter, the third mode converter, and the fourth mode converter have the same structure, the first mode converter and the fourth mode converter are set in the same direction, the second mode converter and the third mode converter are set in the same direction, and the first mode converter and the second mode converter are set in opposite directions.

[0013] Preferably, the mode converter includes a first input single-mode waveguide, an input S-shaped waveguide, a single-mode coupling waveguide, an output S-shaped waveguide, and an output single-mode waveguide connected in sequence, as well as a second input single-mode waveguide, a tapered waveguide, a multimode coupling waveguide, and a multimode output waveguide connected in sequence.

[0014] Preferably, the first mode converter includes:

[0015] silicon substrate;

[0016] Silica undercoat: disposed on one side of the silicon substrate;

[0017] Silicon waveguide layer: disposed on the side of the silicon dioxide under-cladding away from the silicon substrate;

[0018] Silicon dioxide upper cladding: disposed on the side of the silicon waveguide layer away from the silicon dioxide lower cladding.

[0019] Preferably, the first optoelectronic modulation module includes a P-type heavily doped region, an N-type heavily doped region, a P-type lightly doped region, an N-type lightly doped region, a first electrode, a second electrode, an upper silicon dioxide cladding layer, a lower silicon dioxide cladding layer, and a silicon substrate; the lower silicon dioxide cladding layer is located on one side of the silicon substrate, the P-type heavily doped region, the N-type heavily doped region, the P-type lightly doped region, and the N-type lightly doped region are located on the other side of the lower silicon dioxide cladding layer, the P-type heavily doped region is connected to the P-type lightly doped region, the N-type heavily doped region is connected to the N-type lightly doped region, the P-type lightly doped region is connected to the N-type lightly doped region, the first electrode is connected to the N-type heavily doped region, the second electrode is connected to the P-type heavily doped region, the upper silicon dioxide cladding layer is located on the other side of the P-type heavily doped region, the N-type heavily doped region, the P-type lightly doped region, and the N-type lightly doped region, and the first electrode and the second electrode are located in the upper silicon dioxide cladding layer.

[0020] Preferably, a U-shaped carrier depletion region or an L-shaped carrier depletion region is formed between the P-type lightly doped region and the N-type lightly doped region.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] This invention converts the input optical signal coupled into the micro-ring resonator through a mode converter, and then transmits it through the phase modulation region of the micro-ring resonator as a first optical signal, a second optical signal, a fourth optical signal, and a fifth optical signal, respectively. This improves the modulation efficiency of the entire micro-ring resonator, effectively reduces the driving voltage of the micro-ring modulator, and achieves the effect of reducing overall power consumption. Attached Figure Description

[0023] Other features, objects, and advantages of the present invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings:

[0024] Figure 1 This is a schematic diagram of the overall structure of the high modulation efficiency micro-ring modulator of the present invention;

[0025] Figure 2 This is a top view of the structure of the first mode converter of the present invention;

[0026] Figure 3 This is a schematic diagram of the silicon-based electro-optic modulation module structure based on L-type ion doping according to the present invention;

[0027] Figure 4 This is a schematic diagram of the silicon-based electro-optic modulation module structure based on U-shaped ion doping according to the present invention;

[0028] Figure 5 This is a schematic diagram of the structure of a modulation module based on the thermo-optic effect;

[0029] Figure 6This is a schematic diagram showing the relationship between the effective refractive index of the first photoelectric modulation module of the present invention and the applied voltage value;

[0030] Figure 7 This is a schematic diagram comparing the modulation efficiency of the micro-ring modulator of the present invention.

[0031] Explanation of reference numerals in the attached figures:

[0032] Input waveguide 100, first mode converter 500

[0033] Output waveguide 200 First input single-mode waveguide 501

[0034] Adjustable microring resonator 300, input S-shaped waveguide 502

[0035] First half-loop waveguide 301, single-mode coupled waveguide 503

[0036] Second optoelectronic modulation module 302 outputs S-shaped waveguide 504

[0037] First electrode 3021, output single-mode waveguide 505

[0038] Second electrode 3022, second input single-mode waveguide 506

[0039] 3023 cladding on silicon dioxide, 507 tapered waveguide

[0040] 3024 silicon dioxide undercoat, 508 multimode coupled waveguide

[0041] Silicon substrate 3025, multimode output waveguide 509

[0042] N-type heavily doped region 3026 Third mode converter 600

[0043] N-type lightly doped region 3027 Second mode converter 700

[0044] P-type lightly doped region 3028, second feedback loop waveguide 800

[0045] P-type heavily doped region 3029, third semicircular waveguide 801

[0046] Second semi-circular waveguide 303 Second straight waveguide 802

[0047] First optoelectronic modulation module 304; Fourth semicircular waveguide 803

[0048] Heating electrode 3041 First feedback loop waveguide 900

[0049] Silicon ridge waveguide 3042, first semicircular waveguide 901

[0050] Fourth mode converter 400, first direct waveguide 902

[0051] Second semicircular waveguide 903 Detailed Implementation

[0052] The present invention will now be described in detail with reference to specific embodiments. These embodiments will help those skilled in the art to further understand the present invention, but do not limit the invention in any way. It should be noted that those skilled in the art can make several changes and improvements without departing from the concept of the present invention. These all fall within the protection scope of the present invention.

[0053] According to the present invention, a high modulation efficiency micro-ring modulator is provided, with reference to... Figure 1 It includes: an input waveguide 100, an output waveguide 200, an adjustable micro-ring resonator 300, a first feedback loop waveguide 900, a second feedback loop waveguide 800, a first mode converter 500, a second mode converter 700, a third mode converter 600, and a fourth mode converter 400.

[0054] The input waveguide 100 is used to couple the optical signal into the micro-ring resonant cavity to output the first optical signal.

[0055] The first feedback loop waveguide 900 is connected at both ends to an input terminal of the first mode converter 500 and an output terminal of the second mode converter 700, respectively, so as to input the first optical signal into the first mode converter 500.

[0056] The first mode converter 500 is used to perform mode conversion processing on the first optical signal and output the second optical signal.

[0057] The second mode converter 700 is used to perform mode conversion processing on the second optical signal and output the third optical signal.

[0058] The third mode converter 600 is used to perform mode conversion processing on the third optical signal and output the fourth optical signal.

[0059] The fourth mode converter 400 is used to perform mode conversion processing on the fourth optical signal and output the fifth optical signal.

[0060] The second feedback loop waveguide 800 is connected at both ends to an input terminal of the third mode converter 600 and an output terminal of the fourth mode converter 400, respectively, to input the fifth optical signal into the phase modulation arm of the tunable micro-ring resonator 300.

[0061] The adjustable micro-ring resonator 300 is used to modulate the first, second, fourth, and fifth optical signals.

[0062] Output waveguide 200 is used to couple the modulated optical signal out of the micro-ring resonator to output the sixth optical signal.

[0063] In this diagram, the initial optical signal, the first optical signal, the third optical signal, the fifth optical signal, and the sixth optical signal are the first-mode optical signals, and the second optical signal and the fourth optical signal are the second-mode optical signals. It should be noted that the first mode and the second mode can be any optical waveguide mode. The following explanation uses TE0 mode as the first mode and TE1 mode as the second mode as an example.

[0064] The first, second, third, and fourth mode converters have the same structure but are placed in the same or opposite directions. Specifically, the first mode converter 500 and the fourth mode converter 400 are placed in the same direction, while the second mode converter 700 and the third mode converter 600 are placed in the opposite direction. Their function is to convert the input optical signal into optical signals of different order modes (such as TE0, TE1, TE2, TE3, etc.) and output them. Since the two optical signals of different order modes do not interfere or crosstalk with each other during phase modulation by the optoelectronic modulation module, their phase changes can be superimposed, achieving the effect of improving modulation efficiency and reducing device drive voltage as mentioned above. Figure 2 This is a top view of the structure of the first mode converter 500. The structure of the first mode converter 500 includes: a first input single-mode waveguide 501, an input S-shaped waveguide 502, a single-mode coupling waveguide 503, an output S-shaped waveguide 504, an output single-mode waveguide 505, a second input single-mode waveguide 506, a tapered waveguide 507, a multimode coupling waveguide 508, and a multimode output waveguide 509. In terms of the vertical structure, the first mode converter also includes: a silicon substrate; a silicon dioxide lower cladding (disposed on one side of the silicon substrate); a silicon waveguide layer disposed on the side of the silicon dioxide lower cladding away from the silicon substrate; and a silicon dioxide upper cladding layer disposed on the side of the silicon waveguide layer away from the silicon dioxide lower cladding. The function of the first mode converter will be explained below using TE0 and TE1 modes as examples. When TE0 mode light is input from the single-mode waveguide 501, because the coupling region satisfies the phase matching condition for mode conversion, after coupling through the coupling region, the TE1 mode optical signal will be output at the multimode output waveguide 509. When TE0 mode light is input from single-mode waveguide 506, no mode conversion occurs, and the optical signal will be output from multimode waveguide 509 in TE0 mode. Similarly, due to the reversibility of the optical path, when TE1 mode light is input from multimode output waveguide 509, a mode conversion will also occur in the coupling region, and the converted TE0 mode light will be output from the first input single-mode waveguide 501. When TE0 mode light is input from multimode output waveguide 509, no mode conversion will occur in the coupling region, and the optical signal will still be output from the second input single-mode waveguide 506 in TE0 mode.

[0065] The tunable micro-ring resonator 300 further includes: a first optoelectronic modulation module 304, a second optoelectronic modulation module 302, a first half-ring waveguide 301, and a second half-ring waveguide 303. The first optoelectronic modulation module 304 is used for phase modulation of the first and second optical signals. The second optoelectronic modulation module 302 is used for phase modulation of the fourth and fifth optical signals. The first optoelectronic modulation module 304 and the second optoelectronic modulation module 302 are connected through the first half-ring waveguide 301 and the second half-ring waveguide 303, forming a closed ring resonator with tunable resonant wavelength.

[0066] The first optoelectronic modulation module 304 and the second optoelectronic modulation module 302 have the same structure and can be a silicon-based electro-optic modulation module based on ion doping or a silicon-based thermo-optic modulation module. The region of waveguide refractive index change in the modulation module increases with the increase of waveguide width. Figure 3 This is a silicon-based electro-optic modulation module based on L-type ion doping, comprising: a heavily P-type doped region 3029, a heavily N-type doped region 3026, a lightly P-type doped region 3028, a lightly N-type doped region 3027, a first electrode 3021, a second electrode 3022, an upper silicon dioxide cladding layer 3023, a lower silicon dioxide cladding layer 3024, and a silicon substrate 3025. Specifically, a modulation signal is applied to the heavily P-type doped region 3029 and the heavily N-type doped region 3026 through the first electrode 3021 and the second electrode 3022 to adjust the carrier concentration in the lightly P-type doped region 3028 and the lightly N-type doped region 3027. An L-shaped carrier depletion region is formed between the lightly P-type doped region 3028 and the lightly N-type doped region 3027, thereby changing the effective refractive index of the optical signal within the waveguide.

[0067] In some specific embodiments, the first and second optoelectronic modulation modules can also be silicon-based electro-optic modulation modules based on U-type ion doping, with specific structures as follows: Figure 4 As shown, it includes: a heavily doped P-type region 3029, a heavily doped N-type region 3026, a lightly doped P-type region 3028, a lightly doped N-type region 3027, a first electrode 3021, a second electrode 3022, an upper silicon dioxide cladding layer 3023, a lower silicon dioxide cladding layer 3024, and a silicon substrate 3025. Specifically, a modulation electrical signal is applied to the heavily doped P-type region 3029 and the heavily doped N-type region 3026 through the first electrode 3021 and the second electrode 3022 to adjust the carrier concentration in the lightly doped P-type region 3028 and the lightly doped N-type region 3027. A U-shaped carrier depletion region is formed between the lightly doped P-type region 3028 and the lightly doped N-type region 3027, thereby changing the effective refractive index of the optical signal within the waveguide.

[0068] In some specific embodiments, the first and second photoelectric modulation modules can also be modulation modules based on the thermo-optical effect, with specific structures as follows: Figure 5As shown, it includes: a first electrode 3021, a second electrode 3022, a heating electrode 3041, a silicon dioxide upper cladding layer 3023, a silicon ridge waveguide 3042, a silicon dioxide lower cladding layer 3024, and a silicon substrate 3025. Specifically, a modulated electrical signal is applied to the heating electrode 3041 through the first electrode 3021 and the second electrode 3022. When the heating electrode is energized, a thermal effect is generated, causing a temperature change, which in turn changes the temperature of the lower waveguide, thereby changing the effective refractive index of the optical signal within the waveguide.

[0069] The modulator also includes a first feedback loop waveguide 900 and a second feedback loop waveguide 800. Both feedback loop waveguides have identical structures. The first feedback loop waveguide 900 comprises a first semicircular waveguide 901, a first straight waveguide 902, and a second semicircular waveguide 903. The two ends of the first feedback loop waveguide are connected to the first input single-mode waveguide of the first mode converter and the second input single-mode waveguide of the second mode converter, respectively. Its function is to send the modulated first optical signal to the first single-mode input waveguide of the first mode converter for mode conversion, converting it into a second optical signal, which is then phase-modulated again by the first optoelectronic modulation module. The second feedback loop waveguide 800 comprises a third semicircular waveguide 801, a second straight waveguide 802, and a fourth semicircular waveguide 803. Its two ends are connected to the second input single-mode waveguide of the third mode converter and the first input single-mode waveguide of the fourth mode converter, respectively. Its function is to send the fifth optical signal output by the fourth mode converter to the second input single-mode waveguide of the third mode converter, and make it undergo phase modulation again through the second optoelectronic modulation module.

[0070] The following explanation, using TE0 as the first mode optical signal and TE1 as the second mode optical signal, illustrates the specific working principle of this embodiment: The optical signal is input into the input waveguide 100 in TE0 mode and coupled into the tunable micro-ring resonator 300. The light in the resonator propagates counterclockwise, first inputting through the second input single-mode waveguide 506 of the first mode converter 500 and outputting through the multimode output waveguide 509 of the first mode converter. At this time, the output light does not undergo mode conversion and remains in TE0 mode, sequentially entering the first optoelectronic modulation module 304 for phase modulation. The modulated optical signal is input through the multimode output waveguide of the second mode converter, outputting through the second single-mode input waveguide of the second mode converter, returning along the first feedback loop waveguide 900 to the first input single-mode waveguide 501 of the first mode converter, and then input again. At this time, a mode conversion occurs in the first mode converter, changing from the original TE0 mode to TE1 mode. The first optical signal is converted into the second optical signal after mode conversion and output from the multimode output waveguide 509 of the first mode converter. It then undergoes phase modulation again through the first optoelectronic modulation module 304. The modulated TE1 mode second optical signal is input through the multimode output waveguide of the second mode converter. In the second mode converter 700, it undergoes another mode conversion, changing from TE1 mode to TE0 mode, and is output from the first input single-mode waveguide of the second mode converter as the third optical signal. The third optical signal travels along the second half-loop waveguide 303 to the first input single-mode waveguide of the third mode converter. After passing through the third mode converter 600, it is converted back to TE1 mode and output from the multimode output waveguide of the third mode converter. At this point, the output optical signal is the fourth optical signal. The fourth optical signal then enters the second optoelectronic modulation module 302 for phase modulation. After modulation, it is input through the multimode output waveguide of the fourth mode converter, undergoes mode conversion in the fourth mode converter 400, changing to TE0 mode, and is output from the first input single-mode waveguide of the fourth mode converter. At this point, the output optical signal is the fifth optical signal. The fifth optical signal is input again through the second feedback loop waveguide 800 to the second single-mode input waveguide of the third mode converter. No mode conversion occurs; it is output in TE0 mode and then phase-modulated by the second optoelectronic modulation module 302. It is then input in TE0 mode from the multimode output waveguide of the fourth mode converter and output from the second single-mode input waveguide of the fourth mode converter. The signal output from the fourth mode converter 400 is finally coupled to the output waveguide 200 through the first half-loop waveguide 301 and finally output. During the entire process of the micro-ring modulator, the optical signal passes through the first optoelectronic modulation module 304 and the second optoelectronic modulation module 302 twice, in TE0 and TE1 modes respectively, undergoing a total of four phase modulations, which greatly improves the modulation efficiency of the entire micro-ring modulator.

[0071] Please refer to Figure 6The horizontal axis represents the applied voltage value of the first optoelectronic modulation module (actual voltage value, the negative sign indicates the reverse bias voltage of the PN junction, unit is V), and the vertical axis represents the effective refractive index of the TE0 mode and TE1 mode in the waveguide. L41 is the curve showing the relationship between the applied voltage value and the effective refractive index of the TE0 mode, and L42 is the curve showing the relationship between the applied voltage value and the effective refractive index of the TE1 mode. Figure 4 As shown, as the applied voltage of the first optoelectronic modulation module gradually increases, the effective refractive index of both TE0 and TE1 modes gradually increases. This causes the optical signals of TE0 and TE1 modes to accumulate phase changes in the tunable microring resonator. Through the resonance of the microring resonator, the phase change is converted into an intensity change, thereby changing the resonant wavelength of the resonator.

[0072] Please refer to Figure 7 The horizontal axis represents wavelength (in nm), and the vertical axis represents signal power (in dB). L1 is the transmission spectrum of the microring resonator without applied voltage, LTE0 is the transmission spectrum of the resonator of a conventional single-mode microring modulator with an applied voltage of 1V, and LTE0+TE1 is the transmission spectrum of the resonator of the proposed microring modulator with an applied voltage of 1V. Figure 7 As shown, the micro-ring modulator proposed in this application embodiment can achieve a larger wavelength drift under the same operating voltage, and the modulation efficiency is close to twice that of a conventional single-mode micro-ring modulator.

[0073] The tunable micro-ring resonant cavity includes a first optoelectronic modulation module, a second optoelectronic modulation module, a first half-ring waveguide, and a second half-ring waveguide. The first optoelectronic modulation module and the second optoelectronic modulation module are connected through the first half-ring waveguide and the second half-ring waveguide to form a closed ring resonant cavity with tunable resonant wavelength. The two ends of the first half-ring waveguide are respectively connected to a first mode converter and a fourth mode converter, and the two ends of the second half-ring waveguide are respectively connected to a second mode converter and a third mode converter.

[0074] Specific embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the specific embodiments described above, and those skilled in the art can make various changes or modifications within the scope of the claims, which do not affect the essence of the present invention. Unless otherwise specified, the embodiments and features described in this application can be arbitrarily combined with each other.

Claims

1. A high-modulation-efficiency micro-ring modulator, characterized in that, include: Input waveguide (100), output waveguide (200), tunable microring resonator (300), first feedback loop waveguide (900), second feedback loop waveguide (800), first mode converter (500), second mode converter (700), third mode converter (600) and fourth mode converter (400); The input waveguide (100) is used to couple optical signals into the tunable microring resonator (300). The first mode converter (500), the second mode converter (700), the third mode converter (600), and the fourth mode converter (400) are connected in the tunable microring resonator (300). The two ends of the first feedback loop waveguide (900) are respectively connected to an input terminal of the first mode converter (500) and an output terminal of the second mode converter (700). The two ends of the second feedback loop waveguide (800) are respectively connected to an input terminal of the third mode converter (600) and an output terminal of the fourth mode converter (400). The output waveguide (200) is used to couple the modulated optical signals out of the tunable microring resonator (300). The tunable micro-ring resonator (300) includes a first optoelectronic modulation module (304), a second optoelectronic modulation module (302), a first half-ring waveguide (301), and a second half-ring waveguide (303). The first optoelectronic modulation module (304) and the second optoelectronic modulation module (302) are connected through the first half-ring waveguide (301) and the second half-ring waveguide (303) to form a closed ring resonator with tunable resonant wavelength. The two ends of the first half-ring waveguide (301) are respectively connected to the first mode converter (500) and the fourth mode converter (400), and the two ends of the second half-ring waveguide (303) are respectively connected to the second mode converter (700) and the third mode converter (600). The first feedback loop waveguide (900) includes a first semicircular waveguide (901), a first straight waveguide (902), and a second semicircular waveguide (903) connected in sequence. The first semicircular waveguide (901) is connected to the first mode converter (500), and the second semicircular waveguide (903) is connected to the second mode converter (700).

2. The high modulation efficiency micro-ring modulator according to claim 1, characterized in that: The first optoelectronic modulation module (304) and the second optoelectronic modulation module (302) have the same structure. They are silicon-based electro-optic modulation modules or silicon-based thermo-optic modulation modules based on ion doping. The waveguide refractive index change region in the modulation module increases with the increase of the waveguide width.

3. The high modulation efficiency micro-ring modulator according to claim 1, characterized in that: The second feedback loop waveguide (800) includes a third semicircular waveguide (801), a second straight waveguide (802), and a fourth semicircular waveguide (803) connected in sequence. The third semicircular waveguide (801) is connected to the third mode converter (600), and the fourth semicircular waveguide (803) is connected to the fourth mode converter (400).

4. The high modulation efficiency micro-ring modulator according to claim 1, characterized in that: The first mode converter (500), the second mode converter (700), the third mode converter (600), and the fourth mode converter (400) have the same structure. The first mode converter (500) and the fourth mode converter (400) are set in the same direction. The second mode converter (700) and the third mode converter (600) are set in the same direction. The first mode converter (500) and the second mode converter (700) are set in opposite directions.

5. The high modulation efficiency micro-ring modulator according to claim 1, characterized in that: The mode converter includes a first input single-mode waveguide (501), an input S-shaped waveguide (502), a single-mode coupling waveguide (503), an output S-shaped waveguide (504), and an output single-mode waveguide (505) connected in sequence, as well as a second input single-mode waveguide (506), a tapered waveguide (507), a multimode coupling waveguide (508), and a multimode output waveguide (509) connected in sequence.

6. The high modulation efficiency micro-ring modulator according to claim 1, characterized in that: The first mode converter (500) includes: Silicon substrate (3025); The silicon dioxide lower cladding layer (3024) is disposed on one side of the silicon substrate (3025); Silicon waveguide layer: disposed on the side of the silicon dioxide lower cladding (3024) away from the silicon substrate (3025); Silicon dioxide upper cladding (3023): disposed on the side of the silicon waveguide layer away from the silicon dioxide lower cladding (3024).

7. The high modulation efficiency micro-ring modulator according to claim 1, characterized in that: The first optoelectronic modulation module (304) includes a P-type heavily doped region (3029), an N-type heavily doped region (3026), a P-type lightly doped region (3028), an N-type lightly doped region (3027), a first electrode (3021), a second electrode (3022), a silicon dioxide upper cladding layer (3023), a silicon dioxide lower cladding layer (3024), and a silicon substrate (3025); the silicon dioxide lower cladding layer (3024) is located on one side of the silicon substrate (3025), and the P-type heavily doped region (3029), N-type heavily doped region (3026), P-type lightly doped region (3028), and N-type lightly doped region (3027) are located on the other side of the silicon dioxide lower cladding layer (3024). 9) Connected to the P-type lightly doped region (3028), the N-type heavily doped region (3026) is connected to the N-type lightly doped region (3027), the P-type lightly doped region (3028) is connected to the N-type lightly doped region (3027), the first electrode (3021) is connected to the N-type heavily doped region (3026), the second electrode (3022) is connected to the P-type heavily doped region (3029), the silicon dioxide cladding (3023) is located on the other side of the P-type heavily doped region (3029), the N-type heavily doped region (3026), the P-type lightly doped region (3028), and the N-type lightly doped region (3027), and the first electrode (3021) and the second electrode (3022) are located in the silicon dioxide cladding (3023).

8. The high modulation efficiency micro-ring modulator according to claim 7, characterized in that: A U-shaped carrier depletion region or an L-shaped carrier depletion region is formed between the P-type lightly doped region (3028) and the N-type lightly doped region (3027).

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