Driving method and driving circuit of carrier modulator and carrier modulator

Abstract

The present disclosure provides a driving method of a carrier modulator, a driving circuit and the carrier modulator, and relates to the technical field of integrated photonics. The driving method comprises the following steps: applying a direct current bias in the same direction as a PN junction to the carrier modulator, so that the P-doped region and the N-doped region inject carriers into the waveguide region, so as to increase the carrier concentration of the waveguide region; wherein the direct current bias is less than the built-in electric field of the PN junction; applying a radio frequency signal in the opposite direction of the PN junction to the carrier modulator, so that the PN junction is in a reverse bias state; and coupling the direct current bias and the radio frequency signal to the carrier modulator, so as to ensure that the direct current bias and the radio frequency signal are superimposed. The carrier modulator comprises a silicon-based ridge waveguide, the silicon-based ridge waveguide comprises a P-doped region, an N-doped region and a waveguide region, and the waveguide region comprises a PN junction.

Description

Technical Field

[0001] At least one embodiment of this disclosure relates to the field of integrated photonics technology, and more specifically to a driving method, driving circuit, and carrier modulator for a carrier modulator. Background Technology

[0002] Phase modulators based on the electro-optic effect change the refractive index of a crystalline material (such as lithium niobate) under the influence of an applied electric field. By altering the electric field strength, the propagation phase of light within the crystalline material can be changed, thus achieving phase modulation. Phase modulators based on the carrier dispersion principle utilize changes in carrier concentration within a semiconductor material (such as silicon) to influence the propagation characteristics of light. When carriers are injected or extracted, the refractive index of the semiconductor material changes, thereby altering the phase of the light. Phase modulators based on the carrier dispersion principle offer higher integration density and compatibility with CMOS processes, providing advantages in large-scale integration and cost control, and have been widely applied in optical communications.

[0003] Quantum key distribution systems (QKDS) are based on the quantum no-cloning and uncertainty principles, providing high-level information security protection against high-powered attacks. The quantum state modulation in QKDS requires a high-speed phase modulator, and multiple quantum states need to be randomly modulated, often requiring a phase shift of 1.5π. Related technologies can achieve this phase modulation using a phase modulator based on the carrier dispersion principle (or "carrier modulator"). However, due to the need for high-swing radio frequency drive circuits with multiple random levels, the drive circuits for phase modulators used in QKDS present technical challenges, including complexity, difficulty, and high cost.

[0004] Therefore, there is an urgent need for a phase modulator with high modulation efficiency based on the carrier dispersion principle to meet the requirements of quantum key distribution systems and to benefit the development of quantum key distribution technology. Summary of the Invention

[0005] In view of this, this disclosure provides a driving method, driving circuit and carrier modulator for a carrier modulator, which can improve the performance of phase modulators based on the carrier dispersion principle.

[0006] One aspect of this disclosure provides a driving method for a carrier modulator, the carrier modulator including a silicon-based ridge waveguide, the silicon-based ridge waveguide including a P-doped region, an N-doped region, and a waveguide region, the waveguide region including a PN junction; characterized in that the driving method includes: applying a DC bias voltage in the same direction as the PN junction to the carrier modulator, such that carriers from the P-doped region and the N-doped region are injected into the waveguide region to increase the carrier concentration in the waveguide region; wherein the DC bias voltage is less than the built-in electric field of the PN junction; applying a radio frequency signal in the opposite direction to the PN junction to the carrier modulator, such that the PN junction is in a reverse bias state; and coupling the DC bias voltage and the radio frequency signal to the carrier modulator to ensure that the DC bias voltage and the radio frequency signal are superimposed.

[0007] According to embodiments of this disclosure, the method further includes: controlling the amplitude of the radio frequency signal to change the phase shift and modulation depth of the carrier modulator, wherein the larger the amplitude of the radio frequency signal, the larger the phase shift and modulation depth of the carrier modulator.

[0008] Another aspect of this disclosure provides a driving circuit for a carrier modulator, applicable to the driving method described above. The driving circuit includes: a DC driver configured to apply a DC bias voltage in the same direction as the PN junction to the carrier modulator, such that carriers from the P-doped and N-doped regions are injected into the waveguide region to increase the carrier concentration in the waveguide region; wherein the DC bias voltage is less than the built-in electric field of the PN junction; a radio frequency driver configured to apply a radio frequency signal in the opposite direction to the PN junction to the carrier modulator, such that the PN junction is in a reverse bias state; and a bias unit configured to couple the DC bias voltage and the radio frequency signal to the carrier modulator to ensure that the DC bias voltage and the radio frequency signal are superimposed.

[0009] According to an embodiment of this disclosure, the bias device includes a DC terminal, a radio frequency (RF) terminal, and a common terminal; the DC terminal is used to transmit the DC bias voltage to the common terminal and prevent the RF signal from being transmitted to the DC driver; the RF terminal is used to transmit the RF signal to the common terminal and prevent the DC bias voltage from being transmitted to the RF driver; the common terminal is used to output the DC bias voltage and the RF signal to the carrier modulator.

[0010] Another aspect of this disclosure provides a carrier modulator comprising: a silicon-based ridge waveguide including a P-doped region, an N-doped region, and a waveguide region, the waveguide region including a PN junction; the carrier modulator is configured to change the refractive index of the waveguide region based on a change in the carrier concentration of the waveguide region, so as to modulate the optical signal by changing the phase or intensity of the input optical signal.

[0011] According to embodiments of this disclosure, the electrodes of the carrier modulator are configured as copper or tungsten metal materials and connected to the P-doped and N-doped regions via ohmic contacts.

[0012] According to embodiments of this disclosure, the aforementioned P-doped regions are obtained by doping at a single level with the same concentration.

[0013] According to embodiments of this disclosure, the aforementioned P-doped regions are obtained by doping at multiple levels with different concentrations.

[0014] According to embodiments of this disclosure, the aforementioned N-doped regions are obtained by doping at a single level with the same concentration.

[0015] According to embodiments of this disclosure, the aforementioned N-doped regions are obtained by doping at multiple levels with different concentrations.

[0016] According to embodiments of this disclosure, unlike conventional methods of applying a DC bias voltage opposite to the PN junction and an RF drive signal opposite to the PN junction to a carrier depletion modulator (high bandwidth, low modulation efficiency), and also unlike conventional methods of applying a DC bias voltage in the same direction as the PN junction and an RF drive signal in the same direction to a carrier injection modulator (low bandwidth, high modulation efficiency), this method applies a forward DC bias voltage smaller than the built-in electric field of the PN junction to the PN junction-based carrier modulator, and applies an RF voltage opposite to the PN junction, effectively improving the modulation efficiency of carrier modulation. This results in a carrier modulator with high bandwidth and high modulation efficiency, which, when applied to a quantum key distribution system, can effectively reduce the swing requirements of the RF drive circuit. Furthermore, applying a forward DC bias voltage smaller than the built-in electric field of the PN junction-based carrier modulator based on this scheme can also adjust the carrier concentration of the modulator, improving the process error tolerance during carrier doping. Attached Figure Description

[0017] The above and other objects, features and advantages of this disclosure will become clearer from the following description of embodiments of this disclosure with reference to the accompanying drawings.

[0018] Figure 1 An operational flowchart of a driving method for a carrier modulator according to an embodiment of the present disclosure is illustrated schematically.

[0019] Figure 2 A schematic diagram of a drive circuit for a carrier modulator according to an embodiment of the present disclosure is shown.

[0020] Figure 3 A schematic diagram of a carrier modulator according to an embodiment of the present disclosure is shown. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of this disclosure clearer, the following detailed description is provided in conjunction with specific embodiments and the accompanying drawings.

[0022] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit this disclosure. The terms “comprising,” “including,” etc., as used herein indicate the presence of the stated features, steps, operations, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, or components.

[0023] All terms used herein, including technical and scientific terms, have the meanings commonly understood by those skilled in the art, unless otherwise defined. It should be noted that the terms used herein are to be interpreted in a manner consistent with the context of this specification, and not in an idealized or overly rigid way.

[0024] When using expressions such as "at least one of A, B, and C," the meaning should generally be interpreted according to the understanding of someone skilled in the art. For example, "a system having at least one of A, B, and C" should include, but is not limited to, systems having A alone, having B alone, having C alone, having A and B, having A and C, having B and C, and / or having A, B, and C. Similarly, when using expressions such as "at least one of A, B, or C," the meaning should generally be interpreted according to the understanding of someone skilled in the art. For example, "a system having at least one of A, B, or C" should include, but is not limited to, systems having A alone, having B alone, having C alone, having A and B, having A and C, having B and C, and / or having A, B, and C.

[0025] It should also be noted that the directional terms mentioned in the embodiments, such as "up," "down," "front," "back," "left," and "right," are only for reference to the directions in the accompanying drawings and are not intended to limit the scope of protection of this disclosure. Throughout the drawings, the same elements are represented by the same or similar reference numerals. Conventional structures or constructions will be omitted where they may cause confusion in understanding this disclosure.

[0026] Phase modulators based on the carrier dispersion principle are primarily silicon-based carrier modulators, which mainly include carrier injection modulators and carrier depletion modulators. The performance parameters of carrier modulators mainly include modulation efficiency and bandwidth. Modulation efficiency represents the amount of optical phase change that a carrier modulator can induce under a unit voltage, while bandwidth represents the highest frequency range of the signal that the carrier modulator can effectively modulate.

[0027] Carrier injection modulators can be based on a forward-biased PIN structure, where the waveguide body of the modulator is an intrinsic semiconductor or silicon with only background doping. A forward-biased PIN structure includes: a P-region (highly concentrated P-type doped silicon); an N-region (highly concentrated N-type doped silicon); and an I-region (intrinsic semiconductor region or lightly doped, with a doping concentration much lower than the P and N regions, where free carriers are negligible). The P and N regions are located on either side of the I-region of the waveguide body, and the direction of the bias voltage is consistent with the hole diffusion direction, i.e., the diode conduction direction. Generally, a forward bias voltage is applied to the carrier injection modulator. Under the influence of this forward bias voltage, holes from the P-region and electrons from the N-region are injected into the I-region and recombine there, resulting in a carrier concentration in the I-region higher than its intrinsic level. The injected carriers diffuse and recombine in the I-region, significantly changing the effective refractive index of the waveguide body. Therefore, carrier injection modulators have high modulation efficiency. High modulation efficiency means that the modulator can achieve large light intensity changes with a relatively small driving voltage; typically, the driving voltage of a carrier injection modulator is less than 1V. However, due to the limitation of carrier lifetime, the bandwidth of carrier injection modulators is generally not high.

[0028] Carrier depletion modulators can be based on a reverse-biased PN junction structure, where the waveguide of the modulator has P-type doped silicon and N-type doped silicon on both sides, and the two doped regions are in direct contact, thus forming a carrier depletion region in the reverse-biased PN junction. Generally, a reverse bias voltage is applied to the carrier depletion modulator, which strengthens the built-in electric field of the reverse-biased PN junction, causing the depletion region to widen. Carriers in the depletion region are repelled by the built-in electric field, reducing the carrier concentration. By changing the width of the depletion region, the carrier concentration can be controlled to achieve phase modulation. Carrier depletion modulators have a high bandwidth; however, because the width of the depletion region varies within a small range, their modulation efficiency is relatively low, typically one to two orders of magnitude lower than that of carrier injection modulators.

[0029] In quantum key distribution systems, the modulation efficiency and bandwidth of the phase modulator directly affect the system's performance. Carrier injection modulators have high modulation efficiency but low bandwidth, making them unable to respond quickly to high-frequency signals. Carrier depletion modulators have high bandwidth but low modulation efficiency; to achieve the required modulation depth, they require a large RF drive circuit swing, which not only increases circuit complexity but may also lead to higher power consumption and higher cost.

[0030] In related technologies, the performance of phase modulators can be improved by optimizing the doping region, doping concentration, cascading multiple PN junctions, and increasing the DC bias voltage. However, these methods have certain limitations, resulting in limited improvement. Furthermore, process adjustments are also involved. Deviations in photolithography and doping concentration are unavoidable during the fabrication of phase modulators. These deviations can lead to performance differences between phase modulators on different wafers and chips. For example, the actual doping concentration and doping region may not match the design values, resulting in reduced modulation efficiency and bandwidth.

[0031] This disclosure provides a driving method, driving circuit, and carrier modulator for a carrier modulator, aiming to solve at least one of the above-mentioned technical problems.

[0032] Figure 1 An operational flowchart of a driving method for a carrier modulator according to an embodiment of the present disclosure is illustrated schematically.

[0033] like Figure 1 As shown, the driving method of the carrier modulator includes operations S110 to S130.

[0034] According to embodiments of the present disclosure, the carrier modulator includes a silicon-based ridge waveguide, which includes a P-doped region, an N-doped region, and a waveguide region, the waveguide region including a PN junction.

[0035] According to embodiments of this disclosure, a silicon-based ridge waveguide is an optical waveguide implemented on a silicon-based platform through a specific structural design. The silicon-based ridge waveguide may include a top silicon layer, a buried oxide layer, and a substrate, with the ridge structure formed by partially or completely etching the top silicon layer. Ridge waveguides possess high optical field confinement capabilities, effectively enhancing the interaction between light and the waveguide material.

[0036] According to embodiments of this disclosure, a PN junction is a region formed by the contact of a P-type semiconductor and an N-type semiconductor. A silicon-based ridge waveguide forms a P-doped region and an N-doped region by P-doping and N-doping on both sides of the waveguide region, respectively, thereby forming a PN junction in the waveguide region.

[0037] In operation S110, a DC bias voltage in the same direction as the PN junction is applied to the carrier modulator, so that carriers from the P-doped and N-doped regions are injected into the waveguide region to increase the carrier concentration in the waveguide region.

[0038] According to embodiments of this disclosure, the DC bias direction is the conduction direction of the PN junction in the waveguide region. The DC bias is configured to be less than the built-in electric field of the PN junction, keeping the PN junction in a non-conducting state to ensure that the carrier modulator maintains its carrier depletion modulator function. Applying an excessively high DC voltage will cause the PN junction to break down, degrading the bandwidth performance of the carrier modulator. By adjusting the DC bias, the number and distribution of injected carriers can be controlled, thereby improving modulation efficiency.

[0039] In operation S120, an RF signal opposite to that of the PN junction is applied to the carrier modulator, causing the PN junction to be in a reverse bias state.

[0040] According to embodiments of this disclosure, an RF signal opposite to that of the PN junction is applied to the RF input port of the carrier modulator. This RF signal causes the PN junction in the waveguide region to be in a reverse bias state. The reverse bias state reduces the junction capacitance of the PN junction, thereby improving the bandwidth characteristics of the carrier modulator.

[0041] In operation S130, the DC bias voltage and the radio frequency signal are coupled and output to the carrier modulator to ensure that the DC bias voltage and the radio frequency signal are superimposed.

[0042] According to embodiments of this disclosure, unlike conventional methods of applying a DC bias voltage opposite to the PN junction and an RF drive signal opposite to the PN junction to a carrier depletion modulator (high bandwidth, low modulation efficiency), and also unlike conventional methods of applying a DC bias voltage in the same direction as the PN junction and an RF drive signal in the same direction to a carrier injection modulator (low bandwidth, high modulation efficiency), this method applies a forward DC bias voltage smaller than the built-in electric field of the PN junction to the PN junction-based carrier modulator, and applies an RF voltage opposite to the PN junction, effectively improving the modulation efficiency of carrier modulation. This results in a carrier modulator with high bandwidth and high modulation efficiency, which, when applied to a quantum key distribution system, can effectively reduce the swing requirements of the RF drive circuit. Furthermore, applying a forward DC bias voltage smaller than the built-in electric field of the PN junction-based carrier modulator based on this scheme can also adjust the carrier concentration of the modulator, improving the process error tolerance during carrier doping.

[0043] According to embodiments of this disclosure, the driving method for the carrier modulator further includes: controlling the amplitude of a radio frequency signal to change the phase shift and modulation depth of the carrier modulator, wherein the larger the amplitude of the radio frequency signal, the larger the phase shift and modulation depth of the carrier modulator.

[0044] According to embodiments of this disclosure, the performance of the carrier modulator can be dynamically controlled by adjusting the amplitude of the radio frequency signal. A larger radio frequency signal amplitude results in a stronger reverse bias electric field applied to the PN junction, leading to a greater change in carrier concentration in the waveguide region. Since this change in carrier concentration causes refraction changes through plasma dispersion, it leads to an increase in the phase shift and modulation depth of the carrier modulator.

[0045] Based on this, the embodiments of this disclosure can achieve precise adjustment of the modulator phase shift and modulation depth by controlling the amplitude of the radio frequency signal, providing flexibility and controllability for modulator performance optimization.

[0046] Figure 2 A schematic diagram of a drive circuit for a carrier modulator according to an embodiment of the present disclosure is shown.

[0047] like Figure 2 As shown, the driving circuit 210 of the carrier modulator 220 includes a DC driver 211, an RF driver 212, and a biaser 213. The carrier modulator 220 can be an on-chip modulator suitable for integrated photonic chips.

[0048] According to embodiments of this disclosure, the DC driver 211 is configured to apply a DC bias voltage in the same direction as the PN junction to the carrier modulator 220, causing carriers from the P-doped and N-doped regions to be injected into the waveguide region, thereby increasing the carrier concentration in the waveguide region. The DC driver 211 can be an analog DC driver or a digital DC driver, such as a DAC, to provide a stable and accurate DC voltage. The DC driver 211 can provide a stable DC voltage to circuits or other devices through a power supply module, ensuring the accuracy of the DC voltage.

[0049] According to embodiments of this disclosure, the magnitude of the DC bias voltage is configured to be less than the built-in electric field of the PN junction to avoid excessively high bias voltage causing PN junction breakdown or bandwidth performance degradation.

[0050] According to embodiments of this disclosure, the RF driver 212 is configured to apply an RF signal opposite to the PN junction to the carrier modulator 220, causing the PN junction to be in a reverse bias state, expanding the depletion region, reducing the free carrier concentration in the waveguide region, thereby improving the bandwidth performance of the modulator. The RF driver 212 can output a fixed RF signal with high stability and high accuracy, and can provide customized RF signals according to different application scenarios.

[0051] According to embodiments of this disclosure, bias 213 is configured to couple a DC bias voltage and a radio frequency signal to a carrier modulator 220 to ensure effective superposition of the DC bias voltage and the radio frequency signal. The bias 213 can be a bias tee, an adjustable bias, an integrated bias, or the like.

[0052] According to embodiments of this disclosure, bias 213 includes a DC terminal, an RF terminal, and a common terminal.

[0053] According to embodiments of this disclosure, the DC terminal is used to transmit the DC bias voltage from the DC power supply to the common terminal and to prevent the transmission of radio frequency (RF) signals to the DC driver 211, thereby avoiding interference to the DC driver. The RF terminal is used to transmit the RF signal from the RF source to the common terminal and to prevent the transmission of the DC bias voltage to the RF driver 212. The common terminal is used to output the DC bias voltage and the RF signal to the carrier modulator 220.

[0054] According to embodiments of this disclosure, when a DC bias voltage is applied to the biaser through the DC terminal, it is transmitted to the common terminal and then applied to the carrier modulator through the common terminal. Simultaneously, the radio frequency (RF) signal is transmitted to the common terminal through the RF terminal and applied to the modulator together with the DC signal. Due to the design of the biaser, the DC bias voltage and RF signal can be effectively superimposed and coupled to the input carrier modulator. Furthermore, the DC signal and RF signal remain isolated during transmission, preventing interference and ensuring the driving function of the drive circuit.

[0055] Figure 3 A schematic diagram of a carrier modulator according to an embodiment of the present disclosure is shown.

[0056] like Figure 3 As shown, the carrier modulator includes a silicon-based ridge waveguide, which includes a P-doped region, an N-doped region, and a waveguide region. The waveguide region includes a PN junction.

[0057] According to embodiments of this disclosure, the carrier modulator is configured to change the refractive index of the waveguide region based on the change in carrier concentration in the waveguide region, so as to modulate the optical signal by changing the phase or intensity of the input optical signal.

[0058] like Figure 3 As shown, the carrier modulator also includes electrodes, which can be configured as copper or tungsten metal materials and connected to the P-doped and N-doped regions via ohmic contacts.

[0059] like Figure 3As shown, in one example, the electrodes include metal electrode 1 and metal electrode 2, metal electrode 1 being in ohmic contact with the P-doped region and metal electrode 2 being in ohmic contact with the N-doped region.

[0060] According to an embodiment of this disclosure, metal electrode 2 is connected to the common terminal of the bias device, and metal electrode 1 is grounded.

[0061] The carrier modulator of this embodiment is based on a PN junction structure. By applying a forward DC bias voltage smaller than the built-in electric field, carriers from the doped regions on both sides can be injected into the waveguide region, thereby changing the carrier concentration in the waveguide region. Furthermore, by applying a reverse radio frequency signal, the width of the reverse bias structure of the PN junction can be increased, thereby increasing the bandwidth of the waveguide region.

[0062] According to embodiments of this disclosure, the P-doped region can be obtained by doping in a single-stage manner with the same concentration.

[0063] According to embodiments of this disclosure, the P-doped region can be obtained by doping at multiple levels with different concentrations.

[0064] According to embodiments of this disclosure, the N-doped region can be obtained by doping in a single-stage manner with the same concentration.

[0065] According to embodiments of this disclosure, the N-doped region can be obtained by doping at multiple levels with different concentrations.

[0066] According to embodiments of this disclosure, a single-stage doping method with the same concentration means that the dopant concentration remains constant throughout the doping process, requiring only one doping step. This method is relatively simple. A multi-stage doping method with different concentrations means achieving different doping concentrations in different regions through multiple doping steps. This multi-stage method allows for more complex doping concentration distributions, thereby optimizing the performance of the carrier modulator.

[0067] The carrier modulator and its driving circuit of this disclosure improve the modulation efficiency of phase modulators based on the carrier dispersion principle, and also allow for bandwidth adjustment, increasing the phase shift and modulation depth of the phase modulator based on the carrier dispersion principle, thus meeting the quantum state modulation requirements of quantum key distribution systems. The higher modulation efficiency does not require a higher driving voltage, reducing the swing requirements of the RF driving circuit and lowering the technical complexity and cost of the driving circuit. Furthermore, adjusting the carrier concentration through the driving circuit improves the processing error tolerance of the carrier modulator.

[0068] The embodiments of this disclosure have been described above. However, these embodiments are for illustrative purposes only and are not intended to limit the scope of this disclosure. Although various embodiments have been described above, this does not mean that the measures in the various embodiments cannot be used advantageously in combination. Various substitutions and modifications can be made by those skilled in the art without departing from the scope of this disclosure, and all such substitutions and modifications should fall within the scope of this disclosure.

Claims

1. A method for driving a carrier modulator, the carrier modulator comprising a silicon-based ridge waveguide, the silicon-based ridge waveguide comprising a P-doped region, an N-doped region, and a waveguide region, the waveguide region comprising a PN junction; characterized in that, The driving method includes: A DC bias voltage in the same direction as the PN junction is applied to the carrier modulator, so that the carriers in the P-doped region and the N-doped region are injected into the waveguide region to increase the carrier concentration in the waveguide region; wherein the DC bias voltage is less than the built-in electric field of the PN junction; An radio frequency signal opposite to that of the PN junction is applied to the carrier modulator, causing the PN junction to be in a reverse bias state; and The DC bias voltage and the radio frequency signal are coupled and output to the carrier modulator to ensure that the DC bias voltage and the radio frequency signal are superimposed.

2. The driving method according to claim 1, characterized in that, The method further includes: The amplitude of the radio frequency signal is controlled to change the phase shift and modulation depth of the carrier modulator, wherein the larger the amplitude of the radio frequency signal, the larger the phase shift and modulation depth of the carrier modulator.

3. A driving circuit for a carrier modulator, applicable to the driving method described in any one of claims 1 to 2, characterized in that, The driving circuit includes: A DC driver is configured to apply a DC bias voltage in the same direction as the PN junction to a carrier modulator, such that carriers from the P-doped and N-doped regions are injected into the waveguide region to increase the carrier concentration in the waveguide region; wherein the DC bias voltage is less than the built-in electric field of the PN junction. A radio frequency driver configured to apply a radio frequency signal opposite to the PN junction to the carrier modulator, such that the PN junction is in a reverse bias state; and The bias unit is configured to couple the DC bias voltage and the radio frequency signal to the carrier modulator to ensure that the DC bias voltage and the radio frequency signal are superimposed.

4. The driving circuit according to claim 3, characterized in that, The bias unit includes a DC terminal, an RF terminal, and a common terminal; The DC terminal is used to transmit the DC bias voltage to the common terminal and to prevent the radio frequency signal from being transmitted to the DC driver; The radio frequency terminal is used to transmit the radio frequency signal to the common terminal and to prevent the DC bias voltage from being transmitted to the radio frequency driver; The common terminal is used to output the DC bias voltage and the radio frequency signal to the carrier modulator.

5. A carrier modulator, characterized in that, The carrier modulator includes a silicon-based ridge waveguide and a driving circuit as described in any one of claims 3 to 4, wherein the silicon-based ridge waveguide includes a P-doped region, an N-doped region, and a waveguide region, and the waveguide region includes a PN junction; The carrier modulator is configured to change the refractive index of the waveguide region based on the change in carrier concentration in the waveguide region, so as to modulate the optical signal by changing the phase or intensity of the input optical signal.

6. The carrier modulator according to claim 5, characterized in that, The electrodes of the carrier modulator are configured to be made of copper or tungsten metal and are connected to the P-doped and N-doped regions via ohmic contacts.

7. The carrier modulator according to claim 5 or 6, characterized in that, The P-doped region is obtained by doping with the same concentration in a single stage.

8. The carrier modulator according to claim 5 or 6, characterized in that, The P-doped region was obtained by doping at multiple levels with different concentrations.

9. The carrier modulator according to claim 5 or 6, characterized in that, The N-doped region is obtained by doping with the same concentration in a single stage.

10. The carrier modulator according to claim 5 or 6, characterized in that, The N-doped region was obtained by doping at multiple levels with different concentrations.

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