Silicon-based electro-optic phase modulator, chip and related system

Abstract

The embodiment of the invention provides a silicon-based electro-optic phase modulator, a chip and a related system. The silicon-based electro-optic phase modulator comprises a substrate, an optical waveguide layer and an electrode layer, wherein the optical waveguide layer and the electrode layer are stacked on the substrate; the optical waveguide layer comprises a first doped region, and a first PN junction and a second PN junction which are connected in series; the electrode layer includes a first electrode, a second electrode, and a third electrode. The first PN junction is of a convex structure, one end of the first PN junction is connected with the first doped region, and the other end of the first PN junction is connected with the second PN junction; the carrier doping concentration of the first PN junction is smaller than the carrier doping concentration of the second PN junction and smaller than the carrier doping concentration in the first doping area. The first doped region is connected with the first electrode; one end of the second PN junction far away from the first PN junction is connected with the second electrode, and one end close to the first PN junction is connected with the third electrode. According to the embodiment of the invention, the static power consumption and the packaging cost of the silicon-based electro-optic phase modulator can be reduced.

Description

Technical Field

[0001] The present application relates to the field of chip technology, and in particular to a silicon-based electro-optical phase modulator, chip and related system. Background Art

[0002] Microwave photonic technology uses optoelectronic devices to process microwave signals. It has the advantages of large bandwidth, low loss, and anti-electromagnetic interference. It can be applied in wireless communications, radar, instrumentation and other fields. It is an emerging technology that can achieve a leapfrog increase in system capacity and bandwidth. In particular, silicon-based microwave photonic technology can significantly reduce system costs, operating power consumption and improve stability, so as to promote the industrialization of microwave photonic technology.

[0003] Among them, the silicon-based electro-optic phase modulator (EOPM) can modulate the phase information of the light wave when realizing the conversion from electrical signal to optical signal, and can also convert the phase modulation into intensity modulation through the optical link design, making its application in silicon-based microwave photonic technology more flexible, more versatile and more widely used. However, after the DC bias voltage is combined with the RF signal and added to the traveling wave electrode of the EOPM device, the DC bias voltage will eventually fall on the resistor matched at the terminal of the EOPM device (the resistance is usually 50 ohms), generating a DC current, which brings static electrical power consumption to the entire system. Moreover, since the current DC bias voltage is combined with the RF signal and added to the traveling wave electrode of the EOPM device, each silicon-based electro-optic phase modulator needs to be driven by a separate DC bias tee. Since each antenna array needs to correspond to a silicon-based electro-optic phase modulator, in the application scenario where there are many antenna arrays, that is, a large number of EOPM devices are required, the existence of the DC bias tee will significantly increase the electrical packaging cost of the system.

[0004] Therefore, how to reduce the static power consumption and packaging cost of EOPM devices is a technical problem that needs to be solved urgently. Summary of the invention

[0005] The embodiments of the present application provide a silicon-based electro-optic phase modulator, a chip, and a related system, which can reduce the static power consumption and packaging cost of the silicon-based electro-optic phase modulator.

[0006] In a first aspect, an embodiment of the present application provides a silicon-based electro-optic phase modulator, the silicon-based electro-optic phase modulator comprising: a substrate, an optical waveguide layer and an electrode layer stacked on the substrate; the optical waveguide layer comprises a first doped region, a first PN junction and a second PN junction connected in series; the electrode layer comprises a first electrode, a second electrode and a third electrode; wherein the first PN junction is a convex structure, one end of the first PN junction is connected to the first doped region, the other end of the first PN junction is connected to the second PN junction, the carrier doping concentration of the first PN junction is less than the carrier doping concentration of the second PN junction, and less than the carrier doping concentration in the first doped region; the first doped region is connected to the first electrode, and the end of the second PN junction away from the first PN junction is connected to the second electrode, wherein the first electrode is used to receive a radio frequency signal, and the second electrode is used for grounding; or, the first electrode is used for grounding, and the second electrode is used for radio frequency reception signals; the end of the second PN junction close to the first PN junction is connected to the third electrode, and the third electrode is used to receive a DC bias voltage.

[0007] The current silicon-based electro-optical phase modulator has a high packaging cost and generates additional static electrical power consumption, wasting resources. In this regard, the embodiment of the present application provides a silicon-based electro-optical phase modulator that can reduce the static power consumption and packaging cost of the EOPM device. Specifically, the silicon-based electro-optical phase modulator includes a substrate, and an optical waveguide layer and an electrode layer stacked on the substrate. The optical waveguide layer includes a high-concentration doped region (i.e., a first doped region) and two PN junctions connected in series, i.e., a first PN junction and a second PN junction. One of the two PN junctions is a convex PN junction doped with a low concentration (such as the first PN junction), and the other is a PN junction doped with a high concentration (such as the second PN junction). Among them, the other end of the convex PN junction doped with a low concentration is also connected to a high-concentration doped region (such as the first doped region). The outsides of the two PN junctions (i.e., the first doped region and the second PN junction are far away from the first PN junction) are respectively connected to the signal electrode in the upper electrode layer as the input radio frequency signal and the grounded ground electrode. Since the two PN junctions are in series, and the capacitance value of the high-concentration doped PN junction is much greater than that of the low-concentration doped PN junction in the reverse bias state, most of the voltage acts on the low-concentration doped PN junction (i.e., the first PN junction, i.e., the effective electro-optical modulation area), so that the first PN junction can effectively control the phase information of the optical carrier under the driving action of the input RF signal to generate optical modulation sidebands. In the middle area where the two PN junctions are connected, i.e., one end of the second PN junction close to the first PN junction, an electrode (such as the third electrode) in the upper electrode layer that provides a reverse DC bias voltage is connected, so that the carriers in the first PN junction are pulled out of the silicon waveguide area under the action of the external electric field, reducing the absorption loss of the carriers to the optical carrier, while reducing the capacitance / resistance of the first PN junction, ensuring low insertion loss and high modulation bandwidth of the device. In addition, since the input of the DC bias voltage and the input of the RF signal act on both ends of the first PN junction through two different electrodes, the DC bias voltage will not drive the terminal resistance of the silicon-based electro-optical phase modulator in the end, which greatly reduces the static power consumption. Therefore, the silicon-based electro-optical phase modulator provided in the embodiment of the present application can be driven with very little DC bias current to form an effective electro-optical modulation function. Furthermore, due to the separate input of the DC bias voltage and the RF signal, the second PN junction can be used only as a diode, and the function of passing AC and isolating DC can be realized by utilizing its capacitance properties after applying a reverse bias voltage, and the function of passing DC and isolating AC can be realized by utilizing the inductance properties of the narrow metal wire of the third electrode, which is equivalent to directly realizing the function of Bias-Tee on the silicon chip, thereby avoiding the need for an additional separate external electrical Bias-Tee to drive each silicon-based electro-optical phase modulator, thereby reducing the packaging cost of the device.

[0008] In one possible implementation, the first doped region and the end of the first PN junction close to the first doped region are doped with the first type; the end of the first PN junction close to the second PN junction is doped with the second type; the end of the second PN junction close to the first PN junction is doped with the second type; and the end of the second PN junction far from the first PN junction is doped with the first type.

[0009] In the embodiment of the present application, the doping type at the connection between the first PN junction and the second PN junction is the same; the doping type at the connection between the first PN junction and the first doped region is also the same. When the first type of doping is P-type, the second type of doping is N-type; when the first type of doping is N-type, the second type of doping is P-type. In addition, since the silicon-based electro-optical phase modulator in the embodiment of the present application works in a carrier depletion mode, that is, a DC bias voltage is applied based on the third electrode to make its PN junction in a reverse biased state, and in the reverse biased state, the first PN junction is an effective electro-optical modulation region, and the second PN junction is a diode capacitance region. Therefore, according to the different types of carrier doping at the connection of the third electrode in the optical waveguide layer, the polarity of the DC bias voltage applied in the embodiment of the present application is also different.

[0010] In one possible implementation, the first PN junction includes a ridge region, a first flat plate region, and a second flat plate region; one end of the ridge region is connected to the first flat plate region, and the other end of the ridge region is connected to the second flat plate region; one end of the first flat plate region away from the ridge region is connected to the first doped region; and one end of the second flat plate region away from the ridge region is connected to the second PN junction.

[0011] In the embodiment of the present application, the first PN junction is a convex structure, wherein the convex portion is the ridge region of the first PN junction, and the ridge region is a ridge silicon optical waveguide region. Based on the carrier dispersion effect of silicon material, the effective refractive index of the silicon waveguide may change with the change of the applied voltage (i.e., the change of the RF signal), and the change of the effective refractive index may cause the phase information of the light wave passing through the silicon waveguide to change, thereby achieving the phase modulation effect of the optical signal. In addition, the carriers in the ridge region may move away from the PN junction interface under the action of the applied electric field (DC bias voltage) to reduce the absorption loss of the carriers in the ridge region to the optical carrier, and at the same time reduce the capacitance / resistance to ensure the low insertion loss and high modulation bandwidth of the device.

[0012] In one possible implementation, one end of the first slab region and the ridge region connected to the first slab region is doped with the first type; and one end of the second slab region and the ridge region connected to the second slab region is doped with the second type.

[0013] In the embodiment of the present application, there are two different doping types in the ridge region of the first PN junction, that is, a PN junction is formed at the ridge region to achieve electro-optical modulation.

[0014] In a possible implementation, the silicon-based electro-optic phase modulator also includes: an upper cladding layer stacked on the substrate, wherein one end of the upper cladding layer close to the substrate is connected to the optical waveguide layer, and one end of the upper cladding layer away from the substrate is connected to the electrode layer; the upper cladding layer includes a first metal via, a second metal via and a third metal via; one end of the first metal via is connected to the first doped region, and the other end of the first metal via is connected to the first electrode; one end of the second metal via is connected to one end of the second PN junction away from the first PN junction, and the other end of the second metal via is connected to the second electrode; one end of the third metal via is connected to one end of the second PN junction close to the first PN junction, and the other end of the third metal via is connected to the third electrode.

[0015] In the embodiment of the present application, the upper cladding layer is arranged between the optical waveguide layer and the electrode layer, so that the optical waveguide layer and the electrode layer can be electrically connected through the metal through holes in the upper cladding layer, so that they can produce good ohmic contact, providing a simple and effective electrical connection method.

[0016] In a possible implementation, the optical waveguide layer further includes: a second doping region and a third doping region; one end of the second doping region is connected to the first doping region, and the other end of the second doping region is connected to the first PN junction; one end of the third doping region is connected to the first PN junction, and the other end of the third doping region is connected to the second PN junction; the carrier doping concentration in the second doping region and the carrier doping concentration in the third doping region are both lower than the carrier doping concentration in the first doping region; and the carrier doping concentration in the second doping region and the carrier doping concentration in the third doping region are both higher than the carrier doping concentration in the first PN junction.

[0017] In the embodiment of the present application, the carrier doping concentration of the second doping region and the third doping region is in the middle of the adjacent two side regions, that is, the second doping region and the third doping region are medium-concentration doped, and the medium-concentration doping is used as a transition to connect the low and high doping concentration regions, which can reduce the absorption loss of the light field in the ridge silicon optical waveguide caused by high-concentration doping.

[0018] In a possible implementation, the width of the third electrode is less than 10 micrometers.

[0019] In the embodiment of the present application, the width of the third electrode is set to a narrower value, for example, less than 10 microns, so that the third electrode can be used as a DC inductor during operation, directly achieving the function of passing DC and isolating AC.

[0020] In a possible implementation, the silicon-based electro-optic phase modulator further includes an inductor, and the inductor is connected to the third electrode.

[0021] In the embodiment of the present application, in order to enhance the isolation effect of the DC terminal on the AC signal, the third electrode may be further connected to an inductor to enhance the function of passing the DC and isolating the AC.

[0022] In a second aspect, an embodiment of the present application provides a chip, which includes a circuit and the silicon-based electro-optical phase modulator provided in the first aspect above and applied to the circuit.

[0023] In a third aspect, an embodiment of the present application provides an electro-optical phase modulation system, comprising a DC power supply, a plurality of antenna elements, and a plurality of silicon-based electro-optical phase modulators provided in the first aspect above; wherein each of the antenna elements is connected to one of the silicon-based electro-optical phase modulators, and each of the antenna elements is used to output a radio frequency signal to a corresponding silicon-based electro-optical phase modulator, and the DC power supply is connected to the plurality of silicon-based electro-optical phase modulators, and the DC power supply is used to provide a DC bias voltage to each of the silicon-based electro-optical phase modulators.

[0024] It should be understood that the chip provided in the second aspect and the electro-optical phase modulation system provided in the third aspect of the present application are consistent with the technical solution of the first aspect of the present application. Their specific contents and beneficial effects can be referred to the silicon-based electro-optical phase modulator provided in the above-mentioned first aspect, and will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the background technology, the drawings required for use in the embodiments of the present application or the background technology will be described below.

[0026] Figure 1 This is a schematic diagram of the application of a silicon-based electro-optic phase modulator in a microwave photonic system provided by an embodiment of the present application.

[0027] Figure 2 It is a structural schematic diagram of an existing silicon-based electro-optical phase modulator provided in an embodiment of the present application.

[0028] Figure 3 It is a circuit diagram of an existing silicon-based electro-optic phase modulator driving method provided in an embodiment of the present application.

[0029] Figure 4It is a schematic diagram of an electro-optical phase modulation system provided in an embodiment of the present application.

[0030] Figure 5A It is a schematic diagram of the top view structure of a silicon-based electro-optic phase modulator provided in an embodiment of the present application.

[0031] Figure 5B It is a schematic diagram of the cross-sectional structure of a silicon-based electro-optic phase modulator provided in an embodiment of the present application.

[0032] Figure 6 This is a schematic diagram for comparing the capacitance values ​​of two PN junctions provided in an embodiment of the present application.

[0033] Figure 7 It is a schematic diagram of the voltage division ratio of two PN junctions provided in an embodiment of the present application.

[0034] Figure 8 It is a schematic diagram of the cross-sectional structure of another silicon-based electro-optic phase modulator provided in an embodiment of the present application.

[0035] Fig. 9 It is a circuit diagram of a silicon-based electro-optic phase modulator driving method provided in an embodiment of the present application.

[0036] Fig.10 It is a schematic diagram of an equivalent circuit of a silicon-based electro-optic phase modulator provided in an embodiment of the present application.

[0037] Fig.11 This is a schematic diagram of the cross-sectional structure of another silicon-based electro-optic phase modulator provided in an embodiment of the present application.

[0038] Fig.12 It is a schematic diagram of the top view structure of another silicon-based electro-optic phase modulator provided in an embodiment of the present application. DETAILED DESCRIPTION

[0039] The embodiments of the present application will be described below in conjunction with the drawings in the embodiments of the present application.

[0040] The terms "first" and "second" and the like in the specification and claims of the present application and the drawings are used to distinguish different objects, rather than to describe a specific order. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device comprising a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to these processes, methods, products or devices.

[0041] It should be understood that in the present application, "at least one (item)" means one or more, and "plurality" means two or more. "And / or" is used to describe the association relationship of associated objects, indicating that three relationships may exist. For example, "A and / or B" can mean: only A exists, only B exists, and A and B exist at the same time, where A and B can be singular or plural. The character " / " generally indicates that the objects associated before and after are in an "or" relationship. "At least one of the following" or similar expressions refers to any combination of these items, including any combination of single or plural items. For example, at least one of a, b or c can mean: a, b, c, "a and b", "a and c", "b and c", or "a and b and c", where a, b, c can be single or multiple.

[0042] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0043] The terms "component", "module", "system", etc. used in this specification are used to represent computer-related entities, hardware, firmware, a combination of hardware and software, software, or software in execution. For example, a component can be, but is not limited to, a process running on a processor, a processor, an object, an executable file, an execution thread, a program and / or a computer. By way of illustration, both applications running on a computing device and a computing device can be components. One or more components may reside in a process and / or an execution thread, and a component may be located on a computer and / or distributed between two or more computers. In addition, these components may be executed from various computer-readable media having various data structures stored thereon. Components may, for example, communicate through local and / or remote processes according to signals having one or more data packets (e.g., data from two components interacting with another component between a local system, a distributed system and / or a network, such as the Internet interacting with other systems through signals).

[0044] First of all, in order to facilitate understanding of the embodiments of the present application, the technical problems that need to be solved by the embodiments of the present application and the applicable application scenarios are analyzed in detail below.

[0045] Please refer to the attached Figure 1 , Figure 1 This is a schematic diagram of the application of a silicon-based electro-optic phase modulator in a microwave photonic system provided by an embodiment of the present application.

[0046] Silicon-based electro-optic phase modulators (EOPMs) can modulate the phase information of light waves and convert phase modulation into intensity modulation through optical link design. They are more flexible, versatile, and widely used in microwave photonic systems. Compared with Mach-Zehnder modulators and microring resonator modulators, EOPMs do not have the problems of operating point control and temperature sensitivity, which is more conducive to large-scale, low-cost array integrated applications. Figure 1 As shown in the figure, the laser can output an optical carrier (the original unmodulated optical signal); the silicon-based electro-optical phase modulator can adjust the phase information of the optical carrier under the input RF drive signal to generate an optical modulation sideband, that is, to move the RF signal spectrum information to the optical carrier frequency band, and then input it into the back-end optical processor and photodetector, and the photodetector can output the processed RF signal. Therefore, the performance of the silicon-based electro-optical phase modulator directly determines whether the overall function of the system can be realized normally and the level of performance indicators.

[0047] Please refer to the attached Figure 2 and Figure 3 , Figure 2 is a schematic structural diagram of an existing silicon-based electro-optical phase modulator provided in an embodiment of the present application, Figure 3 It is a circuit diagram of an existing silicon-based electro-optic phase modulator driving method provided in an embodiment of the present application.

[0048] like Figure 2 As shown, the device structure of the silicon-based electro-optic phase modulator is a cross-sectional structure cut perpendicular to the propagation direction of the light field. The silicon-based electro-optic phase modulator includes a single optical waveguide with electro-optic modulation effect, that is, a PN junction is formed in the middle of the ridge-type optical waveguide region, as described above. Figure 2 The P region and N region shown in FIG. The planar layer region away from the optical waveguide is connected to the upper traveling wave electrode through a metal via for loading the input RF signal. The planar layer region includes the above Figure 2 The P++ region and N++ region shown in the figure can form a good ohmic contact with the metal via. It should be noted that the ridge optical waveguide region is ion doped with a relatively low concentration, with a doping concentration of 2×10 17 ~5×10 17 cm -3 The slab layer is doped with ions at a higher concentration, with a doping concentration of 1×10 20 ~2×10 20 cm -3 between.

[0049] like Figure 3As shown in the figure, when the silicon-based electro-optic phase modulator is in working state, under the action of input voltage, the carrier concentration in the PN junction region of the silicon waveguide changes with the applied voltage, and then based on the carrier dispersion effect of silicon material, the effective refractive index of the silicon waveguide changes accordingly. At the same time, an external DC bias device (Bias-Tee) is used to combine the DC bias voltage with the RF input signal and load them to the signal electrode of the silicon-based electro-optic phase modulator (such as the electrode connected to the N++ region), so that the PN junction (i.e., the ridge optical waveguide region) is in a reverse bias state, the P region is connected to the negative electrode (such as grounding), and the N region is connected to the positive electrode (such as connected to the DC bias), so that most of the carriers are pulled out of the silicon waveguide region under the action of the external electric field, reducing the absorption loss of the carrier to the optical carrier, and at the same time reducing the PN junction capacitance / resistance, ensuring the low insertion loss and high modulation bandwidth of the silicon-based electro-optic phase modulator.

[0050] However, after the DC bias voltage is combined with the RF signal and added to the traveling wave electrode of the silicon-based electro-optic phase modulator, the DC bias voltage will eventually fall on the terminal matching resistor (as mentioned above). Figure 3 The resistor R shown in the figure, whose resistance is usually 50 ohms), generates a direct current, which brings static electrical power consumption to the system. For example, taking a 3V DC bias voltage as an example, about 180mW of static power consumption will be introduced.

[0051] In addition, since each silicon-based electro-optic phase modulator needs to be driven by a separate DC bias device, the presence of Bias-Tee will significantly increase the electrical packaging cost of the device in application scenarios that require a large number of silicon-based electro-optic phase modulator channels. For example, in a wireless multiple-in multipleout (MIMO) uplink receive link based on microwave photonic technology, the RF signal received by each antenna array requires a silicon-based electro-optic phase modulator to convert the electrical signal into the optical frequency domain. The number of antenna arrays = the number of silicon-based electro-optic phase modulator devices = the number of Bias-Tees required for packaging. Therefore, when the antenna scale is larger, it will reach 1024 channels or even more. Therefore, if the above method is used Figure 3 The driving method shown would result in high packaging costs.

[0052] In this regard, the embodiment of the present application provides a silicon-based electro-optical phase modulator, which loads the DC bias voltage and the sub-port of the RF signal so that the DC bias voltage falls on both ends of the PN junction diode, rather than on both ends of the matching resistor of the existing solution. Therefore, the existence of the DC bias voltage will not generate static current, thereby avoiding the generation of static power consumption. Moreover, the large capacitance property of the cascaded second PN junction is utilized to realize the function of passing AC and isolating DC, and then the DC bias function can be directly realized on the silicon-based EOPM optical chip, avoiding the use of an external DC bias device, thereby reducing the packaging cost of the silicon-based EOPM array integrated chip. Moreover, the embodiment of the present application can be processed on the current standard silicon photonic process production line without making any process changes, thereby reducing the cost of change. Among them, for the specific implementation of the embodiment of the present application, please refer to the description of the following related embodiments, and the embodiment of the present application will not be repeated here.

[0053] Based on the technical issues raised above and to facilitate understanding of the embodiments of the present application, one of the electro-optical phase modulation systems on which the embodiments of the present application are based is described below.

[0054] Taking the electro-optic phase modulation system as the uplink receiving link of a wireless communication base station as an example, the use of the silicon-based electro-optic phase modulator in the system, the related equipment and the working process are illustrated.

[0055] Please refer to the attached Figure 4 , Figure 4 Schematic diagram of an electro-optic phase modulation system provided in an embodiment of the present application. Figure 4 As shown, the electro-optic phase modulation system includes a DC power supply, multiple antenna elements and multiple silicon-based electro-optic phase modulators. It may also include multiple electrical amplifiers, multiple optical filters and a back-end optical domain network.

[0056] Each of the antenna arrays is connected to a silicon-based electro-optical phase modulator, that is, the antenna arrays are connected to the silicon-based electro-optical phase modulators one-to-one, and each of the antenna arrays is used to output a radio frequency signal to the corresponding silicon-based electro-optical phase modulator. In practical applications, silicon-based electro-optical phase modulators can be integrated in parallel arrays. According to the scale of the specific antenna array and the silicon photonics process capabilities, a slice combination method is used to meet the required number of channels, so that each antenna array is connected to a silicon-based electro-optical phase modulator. For example: Figure 4As shown, multiple silicon-based electro-optical phase modulators can be provided by multiple EOPM array chips, and each EOPM array chip includes at least two silicon-based electro-optical phase modulators. Among them, since the RF signal and DC bias voltage in the silicon-based electro-optical phase modulator are input at separate ends, and the DC bias voltage hardly generates static power consumption, the driving capability requirement for the DC power supply is extremely low. Therefore, the DC bias power supply pins in each EOPM array chip can be connected to the same DC power supply, that is, the silicon-based electro-optical phase modulators in each EOPM array chip are powered by the same DC power supply. In other embodiments, some or all of the EOPM array chips in the multiple EOPM array chips can also use the same DC power supply, for example: Figure 4 The DC power supply shown can output a DC bias voltage to the silicon-based electro-optic phase modulators in all EOPM array chips. Compared with existing solutions, this common power supply DC power supply method can greatly reduce the number of DC power supply circuits required and reduce system costs.

[0057] like Figure 4 As shown, the air interface RF signal received by each antenna element is amplified by the corresponding electrical amplifier and input into the RF electrical pin of the corresponding silicon-based electro-optical phase modulator, and the RF electrical pin can be connected to the first electrode in the silicon-based electro-optical phase modulator.

[0058] The silicon-based electro-optic phase modulator in the EOPM array chip outputs a double-sideband modulated optical signal to the corresponding optical filter, which retains one of the RF sidebands and filters out the optical carrier and the other RF sideband. The electro-optic phase modulation system loads the modulated optical signals received by each antenna array with the RF signal and inputs them into the HBF processing network in the optical domain (such as Figure 4 The optical domain network shown in the figure is used to perform amplitude and phase control processing to achieve the function of beamforming. In addition, the optical signal processed by the optical domain network can be input into the photodetector to be converted into an electrical signal. The electrical signal restored by the photodetector is input into the back-end intermediate frequency link and baseband processing link to complete the final signal demodulation.

[0059] In addition, an embodiment of the present application also provides a chip, which includes a circuit and a silicon-based electro-optical phase modulator as described above and applied to the circuit.

[0060] Based on the structure of the electro-optic phase modulation system provided in the above embodiment, a description is given below of one of the silicon-based electro-optic phase modulators on which the embodiments of the present application are based.

[0061] The embodiment of the present application provides a silicon-based electro-optic phase modulator, which includes: a substrate, an optical waveguide layer and an electrode layer stacked on the substrate; the optical waveguide layer includes a first doped region, a first PN junction and a second PN junction connected in series; the electrode layer includes a first electrode, a second electrode and a third electrode; wherein the first PN junction is a convex structure, one end of the first PN junction is connected to the first doped region, the other end of the first PN junction is connected to the second PN junction, the carrier doping concentration of the first PN junction is less than the carrier doping concentration of the second PN junction, and less than the carrier doping concentration in the first doped region; the first doped region is connected to the first electrode, and the first electrode is used to receive a radio frequency signal; an end of the second PN junction away from the first PN junction is connected to the second electrode, and the second electrode is used to be grounded; an end of the second PN junction close to the first PN junction is connected to the third electrode, and the third electrode is used to receive a DC bias voltage.

[0062] Please refer to the attached Figure 5A and Figure 5B , Figure 5A is a schematic diagram of a top view of a silicon-based electro-optic phase modulator provided in an embodiment of the present application, Figure 5B It is a schematic diagram of the cross-sectional structure of a silicon-based electro-optic phase modulator provided in an embodiment of the present application.

[0063] like Figure 5A As shown, the direction 100 represents the propagation direction of the light wave, and the base electro-optic phase modulator is cut along 200, and the following can be obtained: Figure 5B The cross-sectional structure diagram is shown in FIG. Figure 5A As shown, the 22 area in the silicon-based electro-optic phase modulator is the first PN junction as the light-passing and electro-optical modulation area of ​​the silicon-based electro-optic phase modulator, and the 23 area is the second PN junction that does not pass light and is only used as a diode. Its capacitance properties can achieve the function of passing AC and blocking DC. The 21 area is the first doped area. It should be noted that Figure 5A Not reflected in Figure 5B The insulating dielectric portion 44 in the middle and upper cladding layer 40.

[0064] Specifically, Figure 5B As shown, the silicon-based electro-optic phase modulator comprises: a substrate 10, an optical waveguide layer 20 and an electrode layer 30 stacked on the substrate. The substrate 10 comprises a silicon base 11 and a buried oxide layer 12 for support.

[0065] The optical waveguide layer 20 includes a first doped region 21, a first PN junction 22 and a second PN junction 23 connected in series. One end of the first PN junction 22 is connected to the first doped region 21, and the other end of the first PN junction 22 is connected to the second PN junction 23, that is, the first PN junction 22 is arranged between the first doped region 21 and the second PN junction 23. The carrier doping concentration of the first PN junction 22 is less than the carrier doping concentration of the second PN junction 23, and the carrier doping concentration of the first PN junction 22 is less than the carrier doping concentration in the first doped region 21. For example, the first doped region 21 is a high-concentration doped region, the first PN junction 22 is a low-concentration doped convex PN junction, and the second PN junction 23 is a high-concentration doped PN junction. Low-concentration doping means that the carrier doping concentrations of the P region and the N region are both within 2×10 17 ~5×10 17 cm -3 High concentration doping means that the carrier doping concentration of the P region and the N region is between 1×10 20 ~2×10 20 cm -3 The present invention does not specifically limit this embodiment.

[0066] Please refer to the attached Figure 6 and Figure 7 , Figure 6 1 is a schematic diagram for comparing the capacitance values ​​of two PN junctions provided in an embodiment of the present application. Figure 7 Schematic diagram of the voltage division ratio of two PN junctions provided in an embodiment of the present application. Figure 6 As shown in FIG. 1 , the capacitance value of the high-concentration doped PN junction under reverse bias is much greater than the capacitance value of the low-concentration doped PN junction, that is, the capacitance value of the first PN junction (Cpn1) is much smaller than the second PN junction (Cpn2) under reverse bias voltage. Figure 7 As shown, the voltage division ratio of PN junction-1 (i.e., the first PN junction) is above 92%, that is, most of the voltage is applied to the first PN junction, i.e., the effective electro-optical modulation area, so that the first PN junction can effectively control the phase information of the optical carrier under the driving action of the input RF signal to generate optical modulation sidebands.

[0067] In other embodiments, please refer to the attached Figure 8 , Figure 8 FIG. 1 is a schematic diagram of the cross-sectional structure of another silicon-based electro-optic phase modulator provided in an embodiment of the present application. Figure 8As shown, the second PN junction 23 may also be a convex PN junction, and the embodiment of the present application does not specifically limit the shape of the second PN junction 23. In addition, it should be noted that when the second PN junction 23 is a convex structure, the capacitance value Cpn2 corresponding to the second PN junction 23 can be made higher than the capacitance value Cpn1 corresponding to the first PN junction 22, thereby increasing the voltage division ratio of the first PN junction 22 (i.e., the effective electro-optical modulation area) and reducing the RF voltage loss.

[0068] The electrode layer 30 includes a first electrode 31, a second electrode 32 and a third electrode 33; wherein the first doped region 21 is connected to the first electrode 31; the end of the second PN junction 23 away from the first PN junction 22 is connected to the second electrode 32; wherein when the first electrode 31 is used to receive a radio frequency signal, the second electrode 32 is used for grounding; or, when the first electrode 31 is used for grounding, the second electrode 32 is used for receiving a radio frequency signal; the end of the second PN junction 23 close to the first PN junction 22 is connected to the third electrode 33, and the third electrode 33 is used for receiving a DC bias voltage. The present application and the following related embodiments take the example of the first electrode receiving a radio frequency signal and the second electrode being grounded as an example to exemplify the silicon-based electro-optic phase modulator.

[0069] As mentioned above Figure 5B and Figure 8 As shown, in the middle area where the two PN junctions are connected, that is, one end of the second PN junction close to the first PN junction, an electrode (such as a third electrode) connected to the upper electrode layer for providing a reverse DC bias voltage is provided, so that the carriers in the first PN junction can be pulled out of the silicon waveguide area (that is, move in a direction away from the interface of the first PN junction) under the action of an external electric field, so as to reduce the absorption loss of the carriers in the ridge region to the optical carrier, and at the same time reduce the capacitance / resistance, thereby ensuring the low insertion loss and high modulation bandwidth of the device.

[0070] In addition, please refer to the attached Fig. 9 and Fig.10 , Fig. 9 is a circuit diagram of a silicon-based electro-optical phase modulator driving method provided in an embodiment of the present application, Fig.10 Schematic diagram of an equivalent circuit of a silicon-based electro-optic phase modulator provided in an embodiment of the present application. Fig. 9 As shown, since the input of the DC bias voltage and the RF signal are input separately, and act on the two ends of the PN junction through two different electrodes (the first electrode and the third electrode), the DC bias voltage will not drive the terminal resistor R of the silicon-based electro-optic phase modulator, which greatly reduces the static power consumption. PN junction-1 (i.e., the first PN junction) can effectively control the phase information of the optical carrier in the optical waveguide area under the driving action of the input RF signal to generate optical modulation sidebands. As mentioned above Fig.10 As shown above Figure 8 The structure of the silicon-based electro-optic phase modulator shown in the figure, when the first type doping is P type and the second type doping is N type, based on the circuit analysis principle, under the AC high frequency signal V RF Under the action, the resistance impedance voltage division in the two PN junctions is much lower than the capacitance reactance voltage division, so the resistance R of the first PN junction P region can be approximately ignored. 1P , the first PN junction N region resistance R 1N , the second PN junction N region resistance R 2N , the second PN junction P region resistor R 2P Only the voltage-dividing effect of the capacitors Cpn1 and Cpn2 in the two PN junctions needs to be considered. PN junction-2 (i.e., the second PN junction) can be used as a diode under the action of a DC bias voltage, and can be used to apply a reverse bias voltage V DC After that, the function of passing AC and blocking DC is realized based on the capacitance property, and the function of passing DC and blocking AC is realized based on the inductance property of the narrow metal wire of the third electrode, thereby directly realizing the Bias-Tee function on the silicon chip, thereby avoiding the need for a separate DC bias device to drive each silicon-based electro-optic phase modulator. Therefore, the silicon-based electro-optic phase modulator provided in the embodiment of the present application can be driven with very little DC power to form an effective electro-optic modulation function.

[0071] In some embodiments, the silicon-based electro-optic phase modulator further comprises: an upper cladding layer stacked on the substrate. The upper cladding layer comprises a first metal through hole, a second metal through hole and a third metal through hole. In other embodiments, the upper cladding layer further comprises an insulating dielectric portion.

[0072] Among them, as mentioned above Figure 5BAs shown, the upper cladding layer 40 is disposed between the optical waveguide layer 20 and the electrode layer 30, so that the optical waveguide layer and the electrode layer can be electrically connected through a plurality of metal through holes in the upper cladding layer, so that a good ohmic contact can be generated. In addition to the metal through holes, the upper cladding layer also includes an insulating dielectric portion 44. For example: one end of the upper cladding layer 40 close to the substrate 10 is connected to the optical waveguide layer 20, and one end of the upper cladding layer 40 far from the substrate 10 is connected to the electrode layer 30. The upper cladding layer 40 includes a first metal through hole 41, a second metal through hole 42 and a third metal through hole 43; one end of the first metal through hole 41 is connected to the first doped region 21, and the other end of the first metal through hole 41 is connected to the first electrode 31; one end of the second metal through hole 42 is connected to one end of the second PN junction 23 far from the first PN junction 22, and the other end of the second metal through hole 42 is connected to the second electrode 32; one end of the third metal through hole 43 is connected to one end of the second PN junction 23 close to the first PN junction 22, and the other end of the third metal through hole 43 is connected to the third electrode 33.

[0073] In addition, it should be noted that the embodiment of the present application does not specifically limit the number of the first metal vias 41, the second metal vias 42, and the third metal vias 43. Figure 5A As shown, the silicon-based electro-optic phase modulator may include a plurality of first metal vias 41 , a plurality of second metal vias 42 , and a plurality of third metal vias 43 .

[0074] It should also be noted that the embodiment of the present application does not specifically limit the shapes of the first metal via 41, the second metal via 42, and the third metal via 43. For example, the shapes of the first metal via 41, the second metal via 42, and the third metal via 43 in a top view may be rectangular, square, circular, elliptical, triangular, polygonal, etc.

[0075] It should also be noted that the present embodiment does not specifically limit the material of the first metal via 41, the second metal via 42, and the third metal via 43. For example, the material may be a material with good electrical conductivity, such as copper.

[0076] In some embodiments, the first doped region and the end of the first PN junction close to the first doped region are doped with the first type; the end of the first PN junction close to the second PN junction is doped with the second type; the end of the second PN junction close to the first PN junction is doped with the second type; and the end of the second PN junction far from the first PN junction is doped with the first type.

[0077] The first doped region and the end of the first PN junction close to the first doped region are doped with the first type; the end of the first PN junction close to the second PN junction is doped with the second type; the end of the second PN junction close to the first PN junction is doped with the second type; and the end of the second PN junction far from the first PN junction is doped with the first type.

[0078] Wherein, when the first type of doping is P type, the second type of doping is N type; when the first type of doping is N type, the second type of doping is P type. In the embodiment of the present application, the doping type at the connection between the first PN junction and the second PN junction is the same; the doping type at the connection between the first PN junction and the first doped region is also the same. In addition, since the working mode of the silicon-based electro-optical phase modulator in the embodiment of the present application is carrier depletion mode, that is, a DC bias voltage is applied based on the third electrode to make its PN junction in a reverse bias state, and in the reverse bias state, the first PN junction is an effective electro-optical modulation area, and the second PN junction is a diode capacitor area. Therefore, according to the different types of carrier doping at the connection of the third electrode in the optical waveguide layer, the polarity of the DC bias voltage applied in the embodiment of the present application is also different. For example: when the first type of doping is P type and the second type of doping is N type, the DC bias voltage applied is a forward bias voltage. When the first type of doping is N type, the second type of doping is P type, and the DC bias voltage applied is a reverse bias voltage.

[0079] In some embodiments, the first PN junction includes a ridge region, a first flat plate region, and a second flat plate region; one end of the ridge region is connected to the first flat plate region, and the other end of the ridge region is connected to the second flat plate region; one end of the first flat plate region away from the ridge region is connected to the first doped region; and one end of the second flat plate region away from the ridge region is connected to the second PN junction.

[0080] As mentioned above Figure 5B As shown, the first PN junction 22 is a convex structure, wherein the convex portion is a ridge region 221 of the first PN junction, one end of the ridge region 221 is connected to the first flat plate region 222, and the other end of the ridge region 221 is connected to the second flat plate region 223. The ridge region 221 is a ridge silicon optical waveguide region, which can cause the effective refractive index of the silicon waveguide to change with the change of the applied voltage (i.e., the change of the RF signal) based on the carrier dispersion effect of the silicon material. The change of the effective refractive index will cause the phase information of the light wave passing through the silicon waveguide to change, thereby achieving the phase modulation effect of the optical signal. In addition, the carriers in the ridge region 221 will move in a direction away from the PN junction interface under the action of the external electric field (DC bias voltage) to reduce the absorption loss of the carriers in the ridge region to the optical carrier, while reducing the capacitance / resistance to ensure the low insertion loss and high modulation bandwidth of the device.

[0081] In some embodiments, the first slab region and one end of the ridge region connected to the first slab region are doped with the first type; the second slab region and one end of the ridge region connected to the second slab region are doped with the second type.

[0082] As mentioned above Figure 5B and the above Figure 8 As shown, the first slab region 222 and the end of the ridge region 221 connected to the first slab region 222 are doped with the first type of doping; the second slab region 223 and the end of the ridge region 221 connected to the second slab region 223 are doped with the second type of doping. There are two different doping types in the ridge region 221 of the first PN junction 22, that is, a PN junction is formed at the ridge region 221, thereby realizing electro-optical modulation.

[0083] In other embodiments, Figure 8 When the second PN junction 23 shown is a convex structure, the corresponding second PN junction 23 may also include a ridge region 231 of the second PN junction, a third flat region 232 and a fourth flat region 233. The third flat region 232 is arranged at one end of the ridge region 231 of the second PN junction and connected to the second flat region 223, and the fourth flat region 233 is arranged at the other end of the ridge region 231 of the second PN junction, wherein the end of the ridge region 231 of the second PN junction connected to the third flat region 232 is the second type of doping; the fourth flat region 233 and the end of the ridge region 231 of the second PN junction connected to the fourth flat region 233 are the first type of doping.

[0084] In some embodiments, the optical waveguide layer further includes: a second doped region and a third doped region; one end of the second doped region is connected to the first doped region, and the other end of the second doped region is connected to the first PN junction; one end of the third doped region is connected to the first PN junction, and the other end of the third doped region is connected to the second PN junction; the carrier doping concentration in the second doped region and the carrier doping concentration in the third doped region are both lower than the carrier doping concentration in the first doped region; and the carrier doping concentration in the second doped region and the carrier doping concentration in the third doped region are both higher than the carrier doping concentration in the first PN junction.

[0085] With the above Figure 8 For example, please refer to the attached Fig.11 , Fig.11 FIG. 1 is a schematic diagram of the cross-sectional structure of another silicon-based electro-optic phase modulator provided in an embodiment of the present application. Fig.11As shown, the optical waveguide layer further includes: a second doping region 24 and a third doping region 25; one end of the second doping region 24 is connected to the first doping region 21, and the other end of the second doping region 24 is connected to the first PN junction 22; one end of the third doping region 25 is connected to the first PN junction 22, and the other end of the third doping region 25 is connected to the second PN junction 23. The carrier doping concentration in the second doping region 24 and the carrier doping concentration in the third doping region 25 are both lower than the carrier doping concentration in the first doping region 21; and the carrier doping concentration in the second doping region 24 and the carrier doping concentration in the third doping region 25 are both higher than the carrier doping concentration in the first PN junction 22.

[0086] For example, the second doping region 24 and the third doping region 25 are doped with a medium concentration, where the medium concentration doping means that the P-type or N-type carrier doping concentration is both within 1×10 19 ~5×10 19 cm -3 That is, the carrier doping concentration of the second doping region and the third doping region is in the middle of the adjacent two side regions. The embodiment of the present application uses medium concentration doping as a transition to connect the low and high doping concentration regions, which can reduce the absorption loss of the light field in the ridge silicon optical waveguide caused by high concentration doping.

[0087] In addition, it should be noted that the carrier doping type of the second doping region 24 is the first type doping, and the carrier doping type of the third doping region 25 is the second type doping.

[0088] In some embodiments, the width of the third electrode is less than 10 microns. In the embodiment of the present application, the width of the third electrode is set to a narrower value. For example, if the width of the third electrode is set to less than 10 microns, the third electrode can be used as a DC inductor during operation. Moreover, the inductance property embodied by the narrow metal wire of the third electrode cooperates with the capacitance property embodied by the second PN junction after the reverse bias voltage is applied, which can directly realize the function of Bias-Tee, thereby avoiding the need for an additional separate external electrical Bias-Tee to drive each silicon-based electro-optical phase modulator, thereby reducing the packaging cost of the device. In addition, it should be noted that the width of the third electrode refers to, as shown in the above figure Figure 5A or the following Fig.12 The width along the 200 direction is the width of the third electrode, and the length along the 100 direction is the length of the third electrode.

[0089] In some embodiments, the silicon-based electro-optic phase modulator further includes an inductor connected to the third electrode.

[0090] With the above Fig.11 For example, please refer to the attached Fig.12 , Fig.12 is a schematic diagram of a top view of another silicon-based electro-optic phase modulator provided in an embodiment of the present application, such as Fig.12 As shown, in order to further increase the value of the inductor L and enhance the isolation effect of the DC end on the AC signal, the silicon-based electro-optical phase modulator further includes an inductor 50, and the inductor 50 is connected to the third electrode 33. It should be noted that in the direction perpendicular to the substrate, the inductor 50 and the third electrode are located in the same layer, and the inductor 50 can further enhance the isolation effect of the DC end on the AC signal. For example, Fig.12 It should be noted that the embodiment of the present application does not specifically limit the shape and size of the inductor 50. For example, the inductor 50 may use a metal wiring with a spiral or folded structure to reduce the size of the inductor.

[0091] In summary, the embodiment of the present application provides a silicon-based electro-optical phase modulator, which can reduce the static power consumption and packaging cost of the EOPM device. Specifically, the silicon-based electro-optical phase modulator includes a substrate, and an optical waveguide layer and an electrode layer stacked on the substrate, the optical waveguide layer includes a high-concentration doped region (i.e., a first doped region) and two PN junctions connected in series, i.e., a first PN junction and a second PN junction. One of the two PN junctions is a convex PN junction doped with a low concentration (such as the first PN junction), and the other is a PN junction doped with a high concentration (such as the second PN junction). Among them, the other end of the convex PN junction doped with a low concentration is also connected to a high-concentration doped region (such as the first doped region). The outsides of the two PN junctions (i.e., the first doped region and the second PN junction are away from the first PN junction) are respectively connected to the signal electrode (such as the first electrode) and the grounded ground electrode (such as the second electrode) in the upper electrode layer as the input radio frequency signal. The above-mentioned silicon-based electro-optical phase modulator realizes the sub-port input loading of the RF signal and the DC bias, and is isolated from each other by capacitors or inductors, so there will be no coupling influence between each other, and the DC bias function is realized on the chip without the need for an external DC bias device. At the same time, compared with the prior art, the voltage drop of the DC bias voltage in the embodiment of the present application falls on the second PN junction diode. Since the current of the diode is very weak under reverse bias, no electrical power consumption is generated, and the driving capability requirements of the DC power supply are extremely low. Therefore, in application scenarios where the system requires large-scale arrayed silicon-based electro-optical phase modulators to be integrated, multiple silicon-based electro-optical phase modulators can share a DC power supply, such as the above-mentioned Figure 4 The connection method shown is used to reduce the size of peripheral circuits and packaging costs.

[0092] It should be noted that, for the above-mentioned method embodiments, for the sake of simplicity, they are all expressed as a series of action combinations, but those skilled in the art should be aware that the present application is not limited by the order of the actions described, because according to the present application, some steps may be performed in other orders or simultaneously. Secondly, those skilled in the art should also be aware that the embodiments described in the specification are all preferred embodiments, and the actions and modules involved are not necessarily required by the present application.

[0093] In the several embodiments provided in the present application, it should be understood that the disclosed device can be implemented in other ways. For example, the device embodiments described above are only schematic, such as the division of the above-mentioned units, which is only a logical function division. There may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, and the indirect coupling or communication connection of devices or units can be electrical or other forms.

[0094] The units described above as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0095] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional units.

[0096] If the above-mentioned integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application is essentially or the part that contributes to the prior art or all or part of the technical solution can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including a number of instructions to enable a computer device (which can be a personal computer, a server or a network device, etc., specifically a processor in a computer device) to perform all or part of the steps of the above-mentioned methods of each embodiment of the present application. Among them, the aforementioned storage medium may include: U disk, mobile hard disk, magnetic disk, optical disk, read-only memory (Read-Only Memory, abbreviated: ROM) or random access memory (Random Access Memory, abbreviated: RAM) and other media that can store program codes.

[0097] As described above, the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A silicon-based electro-optical phase modulator, characterized in that: The silicon-based electro-optic phase modulator comprises: a substrate, an optical waveguide layer and an electrode layer stacked on the substrate; the optical waveguide layer comprises a first doped region, a first PN junction and a second PN junction connected in series; the electrode layer comprises a first electrode, a second electrode and a third electrode; wherein, The first PN junction is a convex structure, one end of the first PN junction is connected to the first doped region, the other end of the first PN junction is connected to the second PN junction, and the carrier doping concentration of the first PN junction is less than the carrier doping concentration of the second PN junction, and less than the carrier doping concentration in the first doped region; The first doped region is connected to the first electrode, and one end of the second PN junction away from the first PN junction is connected to the second electrode, wherein the first electrode is used to receive a radio frequency signal and the second electrode is used to be grounded; or the first electrode is used to be grounded and the second electrode is used to receive a radio frequency signal; One end of the second PN junction close to the first PN junction is connected to the third electrode, and the third electrode is used to receive a DC bias voltage.

2. The silicon-based electro-optic phase modulator according to claim 1, characterized in that: The first doped region and one end of the first PN junction close to the first doped region are doped with the first type; and one end of the first PN junction close to the second PN junction is doped with the second type; One end of the second PN junction close to the first PN junction is doped with the second type; and one end of the second PN junction far from the first PN junction is doped with the first type.

3. The silicon-based electro-optic phase modulator according to claim 1 or 2, characterized in that: The first PN junction includes a ridge region, a first plate region, and a second plate region; one end of the ridge region is connected to the first plate region, and the other end of the ridge region is connected to the second plate region; One end of the first flat plate region away from the ridge region is connected to the first doped region; and one end of the second flat plate region away from the ridge region is connected to the second PN junction.

4. The silicon-based electro-optic phase modulator according to claim 3, characterized in that: The first slab region and the end of the ridge region connected to the first slab region are doped with the first type; The second slab region and one end of the ridge region connected to the second slab region are doped with the second type of doping.

5. The silicon-based electro-optic phase modulator according to any one of claims 1 to 4, characterized in that: The silicon-based electro-optic phase modulator further comprises: an upper cladding layer stacked on the substrate, wherein one end of the upper cladding layer close to the substrate is connected to the optical waveguide layer, and one end of the upper cladding layer far from the substrate is connected to the electrode layer; the upper cladding layer comprises a first metal through hole, a second metal through hole and a third metal through hole; One end of the first metal through hole is connected to the first doped region, and the other end of the first metal through hole is connected to the first electrode; One end of the second metal through hole is connected to an end of the second PN junction far away from the first PN junction, and the other end of the second metal through hole is connected to the second electrode; One end of the third metal through hole is connected to an end of the second PN junction close to the first PN junction, and the other end of the third metal through hole is connected to the third electrode.

6. The silicon-based electro-optic phase modulator according to any one of claims 1 to 5, characterized in that: The optical waveguide layer further includes: a second doped region and a third doped region; one end of the second doped region is connected to the first doped region, and the other end of the second doped region is connected to the first PN junction; one end of the third doped region is connected to the first PN junction, and the other end of the third doped region is connected to the second PN junction; The carrier doping concentration in the second doping region and the carrier doping concentration in the third doping region are both lower than the carrier doping concentration in the first doping region; and the carrier doping concentration in the second doping region and the carrier doping concentration in the third doping region are both higher than the carrier doping concentration in the first PN junction.

7. The silicon-based electro-optic phase modulator according to any one of claims 1 to 6, characterized in that: The width of the third electrode is less than 10 micrometers.

8. The silicon-based electro-optic phase modulator according to claim 7, characterized in that: The silicon-based electro-optic phase modulator further includes an inductor connected to the third electrode.

9. A chip, characterized in that: The invention comprises a circuit and a silicon-based electro-optic phase modulator as claimed in any one of claims 1 to 8 applied to the circuit.

10. An electro-optic phase modulation system, characterized in that: It comprises a DC power supply, a plurality of antenna elements and a plurality of silicon-based electro-optical phase modulators as claimed in any one of claims 1 to 8; Among them, each of the antenna arrays is connected to one of the silicon-based electro-optical phase modulators, and each of the antenna arrays is used to output a radio frequency signal to the corresponding silicon-based electro-optical phase modulator. The DC power supply is connected to the multiple silicon-based electro-optical phase modulators, and the DC power supply is used to provide a DC bias voltage to each of the silicon-based electro-optical phase modulators.

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