Electro-Optical Modulator

Abstract

Provided is a first optical dividing element including a first input port configured to input an operating signal, a first output port configured to output a main path signal, and a second output port configured to output a first supervisory signal; a second optical dividing element having a 1-in 2-out configuration and an input port of the second optical dividing element connected to the first output port; two waveguide arms, one end of each of the waveguide arms correspondingly connected to two output ports of the second optical dividing element; and a bias voltage modulation module configured to apply a bias voltage to the two waveguide arms based on a bias voltage signal. a radio frequency modulation module configured to apply a radio frequency voltage to the two waveguide arms based on a radio frequency signal; a third optical splitting element having a 2-in-3-out structure and two input ports of the third optical splitting element correspondingly connected to the other ends of each of the two waveguide arms; and a fourth optical splitting element having a 1-in-2-out structure and an input port of the fourth optical splitting element connected to the first output port of the third optical splitting element, the fourth optical splitting element including a third output port configured to output a maximum optical power value and a fourth output port configured to output a second monitoring signal.

Description

[Technical field]

[0001] The present disclosure relates to the field of optical communications, and in particular to electro-optic modulators. [Background technology]

[0002] In recent years, with the rapid development of emerging network application services such as Internet of Things, unmanned driving, remote medical care, and long-distance education, higher requirements have been put forward for high-speed and large-capacity communication technology. Optical communication has achieved rapid development in the aspect of high-speed and large-capacity communication due to its characteristics such as large bandwidth, high reliability, low cost, and strong anti-interference ability. How to impose high-speed electrical signals onto optical carrier waves is the core research content.

[0003] An electro-optic modulator is a type of modulator that is built on the electro-optic effect of electro-optic materials. The electro-optic effect means that when a voltage is applied to an electro-optic material, such as lithium niobate, gallium arsenide, or lithium tantalate crystals, the refractive index of the electro-optic material will vary, thereby causing a change in the properties of the light waves traveling through the electro-optic material. The use of the electro-optic effect allows for modulation of parameters such as phase, amplitude, intensity, and polarization state of an optical signal.

[0004] Increasingly pressing requirements for high speed and large capacity communication technology have placed higher requirements on the operational performance of electro-optical modulators. Summary of the Invention

[0005] The present disclosure provides an optical fiber splitter including a first optical dividing element including a first input port configured to input an operating signal, a first output port configured to output a main path signal, and a second output port configured to output a first monitor signal; a second optical dividing element having a 1-in 2-out structure and an input port of the second optical dividing element connected to the first output port; two waveguide arms, one end of each of the waveguide arms correspondingly connected to two output ports of the second optical dividing element; and a bias voltage modulation module configured to apply a bias voltage to the two waveguide arms based on a bias voltage signal; An electro-optical modulator is provided, comprising: a radio frequency modulation module configured to apply a radio frequency voltage to two waveguide arms based on a radio frequency signal; a third optical splitting element having a 2-in-3-out structure and two input ports of the third optical splitting element correspondingly connected to the other ends of each of the two waveguide arms; and a fourth optical splitting element having a 1-in-2-out structure and an input port of the fourth optical splitting element connected to a first output port of the third optical splitting element, the fourth optical splitting element including a third output port configured to output a maximum optical power value and a fourth output port configured to output a second monitoring signal.

[0006] In some embodiments, when the electro-optical modulator is in an operating state, the optical power input from the first input port is represented by P1, the optical power output from the first output port is represented by P2=P1*(100-A)%, and the optical power output from the second output port is represented by P3=P1*A%, where A% is less than 50%.

[0007] In some embodiments, the electro-optical modulator further includes a fifth optical splitting element having a 1-in-2-out structure and an input port of the fifth optical splitting element connected to the second output port of the third optical splitting element, the fifth output port configured to output the third monitor signal, and a sixth output port configured to output the fourth monitor signal.

[0008] In some embodiments, A% is a constant value, or A% is determined based on a power ratio of the third monitor signal to the fourth monitor signal.

[0009] In some embodiments, the electro-optical modulator further includes a sixth optical splitting element having a 1-in-2-out structure and an input port of the sixth optical splitting element connected to the third output port of the third optical splitting element, the sixth optical splitting element including a seventh output port configured to output the fifth monitor signal, and an eighth output port configured to output the sixth monitor signal.

[0010] In some embodiments, the electro-optical modulator further includes a feedback module configured to adjust the bias voltage signal output to the bias voltage modulation module based on at least one of the first monitor signal, the second monitor signal, the third monitor signal, the fourth monitor signal, the fifth monitor signal, and the sixth monitor signal.

[0011] In some embodiments, the first optical dividing element further includes a second input port configured to input the detection signal.

[0012] In some embodiments, when the electro-optical modulator is in a detection state, the optical power input from the second input port is represented by P0, the optical power output from the first output port is represented by P4=P0*A%, the optical power output from the second output port is represented by P5=P0*(100-A)%, the maximum optical power value output from the third output port is represented by P6, the maximum optical power value output from the fourth output port is represented by P7=P6*A%, and the transmission loss of the electro-optical modulator is represented by C=P6 / P4.

[0013] In some embodiments, the first input port of the first optical splitting element and the second input port of the first optical splitting element have exchange symmetry, and the first output port and the second output port have exchange symmetry.

[0014] In some embodiments, the third output port of the fourth optical dividing element and the fourth output port of the fourth optical dividing element have exchange symmetry, and / or the fifth output port of the fifth optical dividing element and the sixth output port of the fifth optical dividing element have exchange symmetry.

[0015] In some embodiments, the seventh output port of the sixth optical splitting element and the eighth output port of the sixth optical splitting element have exchange symmetry.

[0016] In some embodiments, the first output port of the third optical splitting element is configured to output a maximum optical power value of the coherently amplified signal of the two branch optical signals having a phase difference of 2NΠ, where N is 0 or a natural number, and the second output port and the third output port of the third optical splitting element are configured to correspondingly output a set allocation percentage of the maximum optical power value of the coherently amplified signal of the two branch optical signals having a phase difference of (2N+1)Π, where the set allocation percentage is greater than 0 and less than 1.

[0017] In some embodiments, the third light dividing element has an axially symmetric structure, and the second output port and the third output port of the third light dividing element are symmetrically disposed with respect to the first output port.

[0018] In some embodiments, the electro-optic modulator is configured in a NRZ or PAM4 encoding format.

[0019] It should be understood that the contents described in this section are not intended to identify critical or important features of the embodiments of the present disclosure, and are not to be used to limit the scope of the present disclosure. Other features of the present disclosure will be readily understood with reference to the description that follows.

[0020] More details, features and advantages of the present disclosure are disclosed in the following description of exemplary embodiments, with reference to the accompanying drawings. [Brief description of the drawings]

[0021] [Figure 1] FIG. 1 is a top view of a simplified structure of a conventional electro-optic modulator. [Diagram 2] 1 is a schematic diagram of a simplified structure of an electro-optic modulator according to some embodiments of the present disclosure. [Diagram 3] 11 is a curve graph illustrating the correlation between the optical power output from the first output port and the second output port of the third optical splitting element and the phase difference between the two branched optical signals arriving at the third optical splitting element in accordance with some embodiments of the present disclosure. [Figure 4] 4 is a schematic diagram of a simplified structure of an electro-optic modulator in accordance with some other embodiments of the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0022] Only some exemplary embodiments are briefly described below. As can be appreciated by those skilled in the art, the described embodiments can be modified in various ways without departing from the spirit or scope of the present disclosure. Accordingly, the accompanying drawings and descriptions are to be regarded as illustrative in nature and not restrictive.

[0023] A Mach-Zehnder modulator is a type of electro-optic modulator in which an input optical signal is split into two branch optical signals, which then enter two waveguide arms respectively. The two waveguide arms are each made of electro-optic material and have a refractive index that varies with the applied modulation voltage. The change in the refractive index of the waveguide arms can lead to a change in the phase of the branch optical signals. Therefore, the output from the convergence of the two branch optical signals is an interference signal with an intensity that varies with the modulation voltage. In short, the Mach-Zehnder modulator can implement modulation of different sidebands by controlling the modulation voltages applied to the two waveguide arms. As a device for converting electrical signals to optical signals, the Mach-Zehnder modulator is one of the common core devices in optical interconnection, optical computing, and optical communication systems.

[0024] FIG. 1 shows a schematic structural diagram of a conventional Mach-Zehnder modulator. Ideally, the Mach-Zehnder modulator 001 has two waveguide arms 02 that are identical to each other. When the Mach-Zehnder modulator 001 is not working, neither of the two waveguide arms 02 undergoes electro-optical effects. An input light travels through an optical splitting element 01 and is then equally split into two branch optical signals. The two branch optical signals are still in the same phase after traveling through one waveguide arm 02 respectively, and therefore a coherently amplified signal of the two branch optical signals is output from an optical combining element 05. When the Mach-Zehnder modulator 001 is operating, the modulation electrodes 04 (e.g., including the signal electrode 040, the first ground electrode 041, and the second ground electrode 042) apply a modulation voltage to the two waveguide arms 02, and the two branch optical signals may differ in phase by an odd or even multiple of Π after each of the two branch optical signals travels through one waveguide arm 02. When the two branch optical signals differ in phase by an even multiple of Π, the optical combining element 05 outputs a coherently amplified signal of the two branch optical signals. When the two branch optical signals differ in phase by an odd multiple of Π, the optical combining element 05 outputs a coherent cancellation signal of the two branch optical signals.

[0025] However, in practice, the two waveguide arms 02 cannot be absolutely identical due to reasons such as materials and charge accumulation, and when the Mach-Zehnder modulator 001 is not working, a certain phase shift will appear after the two branched optical signals pass through one waveguide arm 02 respectively, and this phase shift is unavoidable and is an inherent phase difference, which may fluctuate with changes in time and environmental conditions, and the existence of this phase shift will affect the accuracy of the output signal when the Mach-Zehnder modulator 001 is working, or even make it impossible for the Mach-Zehnder modulator 001 to perform normal output.

[0026] Therefore, it is required to perform bias voltage modulation on the two waveguide arms by a bias voltage modulation module to compensate for the phase shift caused by the inherent difference between the two waveguide arms, so as to improve the accuracy of the operating signal output from the electro-optical modulator, thereby improving the operating performance of the electro-optical modulator.

[0027] SUMMARY OF THE DISCLOSURE An embodiment of the present disclosure provides an electro-optic modulator to improve the accuracy of an operating signal output from the electro-optic modulator.

[0028] As shown in FIG. 2 , an electro-optical modulator 100 provided in accordance with some embodiments of the present disclosure includes a first optical splitting element 10, a second optical splitting element 20, two waveguide arms 70, a bias voltage modulation module 80, a radio frequency modulation module 90, a third optical splitting element 30, and a fourth optical splitting element 40.

[0029] The first optical splitting element 10 includes a first input port 101 configured to input an operating signal, a first output port 103 configured to output a main path signal, and a second output port 104 configured to output a first monitoring signal. The second optical splitting element 20 has a 1-in 2-out structure and an input port of the second optical splitting element 20 connected to the first output port 103, and is configured to equally split the optical signal input from the input port into two branch optical signals. The two waveguide arms 70 correspondingly provide transmission paths for the two branch optical signals, and one end of each of the waveguide arms is correspondingly connected to the two output ports of the second optical splitting element 20. The third optical splitting element 30 has a 2-in 3-out structure and two input ports of the third optical splitting element 30 correspondingly connected to the other end of each of the two waveguide arms 70, and is configured to correspondingly receive the branch optical signals transmitted by the two waveguide arms 70. The fourth optical splitting element 40 has a 1-in 2-out structure and an input port of the fourth optical splitting element 40 connected to the first output port 301 of the third optical splitting element 30, and the fourth optical splitting element 40 includes a third output port 401 configured to output a maximum optical power value and a fourth output port 402 configured to output a second monitoring signal.

[0030] The radio frequency modulation module 90 is configured to apply a radio frequency voltage to the two waveguide arms 70 based on the radio frequency signal to perform radio frequency modulation on the two branch optical signals transmitted in those waveguide arms 70. The bias voltage modulation module 80 is configured to apply a bias voltage to the two waveguide arms 70 based on the bias voltage signal to perform bias voltage modulation on the two branch optical signals transmitted in those waveguide arms 70.

[0031] In this disclosure, each optical splitting element refers to an optical power allocation element, for example, a multi-mode interference element with optical power allocation function. Designers can design the actual structure of the optical splitting element according to the designed allocation ratio of optical power. When the electro-optical modulator 100 is in an operating state, the optical power input from the first input port 101 is represented by P1, the optical power output from the first output port 103 is represented by P2=P1*(100-A)%, and the optical power output from the second output port 104 is represented by P3=P1*A%.

[0032] In the embodiment of the present disclosure, based on the first monitoring signal output from the second output port 104 of the first optical splitting element 10, it can be monitored whether the operating signal input from the first input port 101 is normal, for example, whether the power for coupling the operating signal into the electro-optical modulator 100 can reach the target power. Based on the second monitoring signal output from the fourth output port 402 of the fourth optical splitting element 40 and the signal output from the second output port 302 or the third output port 303 of the third optical splitting element 30, it can be monitored whether the operating state of the electro-optical modulator 100 is normal, for example, whether the two branched optical signals reach the target phase difference.

[0033] Referring to FIG. 3, FIG. 3 is a curve graph showing the correlation between the optical power output from the first output port 301 and the second output port 302 (and possibly the third output port 303) of the third optical splitting element 30 and the phase difference between the two branched optical signals.

[0034] When the optical power ratio K of the second monitoring signal (which is a set percentage of the optical power output from the first output port 301) output from the fourth output port 402 to the signal output from the second output port 302 or the third output port 303 of the third optical splitting element 30 reaches a maximum value, it can be obtained that the phase difference between the two branch optical signals is 0 or an even multiple of Π, and when the ratio K reaches a minimum value, it can be obtained that the phase difference between the two branch optical signals is an odd multiple of Π.

[0035] Therefore, through the design of the embodiments of the present disclosure, the operating signal and operating state input into the electro-optical modulator 100 can be effectively monitored, and based on these monitoring information, the bias voltage signal output to the bias voltage modulation module 80 can be adjusted to compensate for the phase shift caused by the inherent difference between the two waveguide arms 70, thereby improving the accuracy of the operating signal output from the electro-optical modulator 100 in the operating state.

[0036] At least one target phase difference required to be achieved by the two branched optical signals can be determined in advance based on the encoding method and the target output of the electro-optical modulator 100. The encoding method of the electro-optical modulator 100 includes, but is not limited to, the NRZ encoding method and the PAM4 encoding method. The encoding method of the electro-optical modulator 100 is various, and the specific setting value of the target phase difference is also various.

[0037] In some embodiments, the electro-optical modulator 100 uses an NRZ (non-return to zero) encoding scheme, so that the two branch optical signals can generate a first target phase difference φ1 and a second target phase difference φ2, where the first target phase difference φ1 and the second target phase difference φ2 satisfy |φ1-(2NΠ+Π / 2)|=|φ2-(2NΠ+Π / 2)|. For example, the first target phase difference φ1 is represented by 2Nπ and the second target phase difference φ2 is represented by (2N+1)π, or the first target phase difference φ1 is represented by 2Nπ+3π / 10 and the second target phase difference φ2 is represented by 2Nπ+7π / 10, or the first target phase difference φ1 is represented by 2Nπ+π / 10 and the second target phase difference φ2 is represented by 2Nπ+9π / 10, etc., which are not enumerated in this specification. The control chip of the electro-optical modulator 100 outputs a radio frequency modulation signal to the radio frequency modulation module 90 according to the first target phase difference φ1 and the second target phase difference φ2.

[0038] In some other embodiments, the electro-optical modulator 100 uses a PAM4 (four-level pulse amplitude modulation) encoding scheme, so that the two branch optical signals can produce a first target phase difference φ1, a second target phase difference φ2, a third target phase difference φ3, and a fourth target phase difference φ4. The first target phase difference φ1, the second target phase difference φ2, the third target phase difference φ3, and the fourth target phase difference φ4 satisfy |φ1-Π / 2|=3|φ2-Π / 2|=3|φ3-Π / 2|=|φ4-Π / 2|. The control chip of the electro-optical modulator 100 outputs a radio frequency modulation signal to the radio frequency modulation module 90 according to the first target phase difference φ1, the second target phase difference φ2, the third target phase difference φ3, and the fourth target phase difference φ4.

[0039] In some embodiments of the present disclosure, the first output port 301 of the third optical splitting element 30 is configured to output a maximum optical power value (corresponding to a maximum energy value or maximum intensity value of the coherently augmented signal) of the two branch optical signals having a phase difference of 2NΠ, where N is 0 or a natural number, and the second output port 302 and the third output port 303 of the third optical splitting element 30 are configured to correspondingly output a set allocation percentage of the maximum optical power value (corresponding to a maximum energy value or maximum intensity value of the coherently augmented signal) of the two branch optical signals having a phase difference of (2N+1)Π, where the set allocation percentage is greater than 0 and less than 1.

[0040] The specific value of the set allocation ratio mentioned above is not limited. For example, the signals correspondingly output from the second output port 302 and the third output port 303 of the third optical splitting element 30 can both reach 50% of the maximum optical power value of the coherently amplified signal of the two branch optical signals with a phase difference of (2N+1)Π. As another example, the signal output from the second output port 302 of the third optical splitting element 30 can reach 40% of the maximum optical power value of the coherently amplified signal of the two branch optical signals with a phase difference of (2N+1)Π, and the signal output from the third output port 303 of the third optical splitting element 30 can reach 60% of the maximum optical power value of the coherently amplified signal of the two branch optical signals with a phase difference of (2N+1)Π. After the set allocation ratio is determined, the specific structural dimensions of the third optical splitting element 30 can be designed based on the set allocation ratio.

[0041] When the phase difference between the two branched optical signals is (2N+1)Π, the two branched optical signals still produce coherent enhancement by utilizing the multi-mode interference effect of the third optical splitting element 30, and the coherently amplified signals are either equally divided or proportionally allocated between the second output port 302 and the third output port 303 of the third optical splitting element 30 and output as monitoring signals, and can reach the maximum optical power value of those coherently amplified signals. Therefore, according to the technical solutions of the embodiments of the present disclosure, a relatively strong monitoring signal can be obtained without significantly weakening the intensity of the operating signal output from the electro-optical modulator 100, thereby ensuring the effectiveness of the monitoring.

[0042] In some embodiments, the third optical splitting element 30 has an axially symmetric structure, and the second output port 302 and the third output port 303 of the third optical splitting element 30 are symmetrically disposed with respect to the first output port 301. Such a design may allow the overall structure to be symmetric, thereby weakening the element's dependence on wavelength, such that the electro-optic modulator 100 is applicable to a wider signal waveband and has a larger application range.

[0043] 4, in some embodiments of the present disclosure, the electro-optical modulator 100 further includes a fifth optical splitting element 50 having a 1-in-2-out structure and an input port of the fifth optical splitting element 50 connected to the second output port 302 of the third optical splitting element 30, the fifth output port 501 configured to output the third monitor signal, and a sixth output port 502 configured to output the fourth monitor signal, and a sixth optical splitting element 60 having a 1-in-2-out structure and an input port of the sixth optical splitting element 60 connected to the third output port 303 of the third optical splitting element 30, the sixth output port 60 having a 1-in-2-out structure and an input port of the sixth optical splitting element 60 connected to the third output port 303 of the third optical splitting element 30, the seventh output port 601 configured to output the fifth monitor signal, and an eighth output port 602 configured to output the sixth monitor signal. The structures of the fifth optical splitting element 50 and the sixth optical splitting element 60 may be completely identical. In addition, only one of the fifth light dividing element 50 and the sixth light dividing element 60 may be disposed.

[0044] In some embodiments of the present disclosure, the first input port 101 of the first optical splitting element 10 and the second input port 102 of the first optical splitting element 10 have exchange symmetry, the first output port 103 and the second output port 104 have exchange symmetry, and / or the third output port 401 of the fourth optical splitting element 40 and the fourth output port 402 of the fourth optical splitting element 40 have exchange symmetry, and / or the fifth output port 501 of the fifth optical splitting element 50 and the sixth output port 502 of the fifth optical splitting element 50 have exchange symmetry, and / or the seventh output port 601 of the sixth optical splitting element 60 and the eighth output port 602 of the sixth optical splitting element 60 have exchange symmetry.

[0045] In the present disclosure, A% may be a constant value determined according to experience, or may be a constant value determined based on the power ratio of the third monitoring signal to the fourth monitoring signal. In some embodiments of the present disclosure, the A% mentioned above is less than 50%, for example, A% is valued as 3% or 5%. By tapping off a small portion of the optical power and coupling the optical power to the second output port 104, the operating signal input from the first input port 101 can be monitored, which can ensure the validity of the monitoring, and the modulation efficiency of the electro-optical modulator 100 can also be guaranteed.

[0046] 4, in some embodiments of the present disclosure, the first optical splitting element 10 further includes a second input port 102 configured to input a detection signal. The second input port 102 can be used as a debugging and detection input port of the electro-optical modulator 100 during product development or testing. When the electro-optical modulator 100 is in a detection state, the optical power input from the second input port 102 is represented by P0, the optical power output from the first output port 103 is represented by P4=P0*A%, the optical power output from the second output port 104 is represented by P5=P0*(100-A)%, the maximum optical power value output from the third output port 401 is represented by P6, the maximum optical power value output from the fourth output port 402 is represented by P7=P6*A%, and the transmission loss of the electro-optical modulator 100 is represented by C=P6 / P4. A% is less than 50%, for example, A% is valued as 3% or 5%, which may allow most of the optical power to be output from the second output port 104, thus improving the detection accuracy.

[0047] Based on the monitored values ​​of at least some of the parameters, such as P0, P4, P5, P6, P7, etc., the transmission loss of the electro-optic modulator 100 using a particular design can be calculated. If the transmission loss is controlled within the target range, the product meets the ex-factory design requirements; if the transmission loss is larger and not within the target range, the specific construction details of the product can be redesigned to reduce the transmission loss.

[0048] In some embodiments of the present disclosure, the electro-optical modulator 100 further includes a feedback module configured to adjust the bias voltage signal output to the bias voltage modulation module 80 based on at least one of the first monitor signal, the second monitor signal, the third monitor signal, the fourth monitor signal, the fifth monitor signal, and the sixth monitor signal. The feedback module may include a signal strength monitor sensor located at a corresponding monitor output port, and the signal strength monitor sensor may detect the monitor signal output from the output port in real time or at a certain frequency, provided that the output operating signal of the electro-optical modulator 100 meets the accuracy requirement.

[0049] In an embodiment, the electro-optic modulator 100 itself has the function of monitoring the operating signal and the operating state, and can automatically and dynamically adjust the bias voltage signal output to the bias voltage modulation module 80 based on these monitoring information to compensate for the phase shift caused by the inherent difference between the two waveguide arms 70, so that the accuracy and reliability of the operating signal output from the electro-optic modulator 100 can be improved. In some embodiments, when the strength of some monitoring signals does not reach the target strength value (e.g., the first monitoring signal is lost or extremely weak), the feedback module can further activate the alarm unit of the electro-optic modulator 100 to give an alarm prompt.

[0050] In this description, the orientations, positional relationships, or dimensions indicated by terms such as "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "lower," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" are orientations, positional relationships, or dimensions shown based on the accompanying drawings, and it should be understood that these terms are used solely for ease of description, rather than as an indication or suggestion that the referred to device or element has a particular orientation and must be constructed and operated in this particular orientation, and therefore should not be construed as limiting the scope of protection of the present disclosure.

[0051] In addition, terms such as "first," "second," and "third" are for descriptive purposes only and should not be construed as indicating or suggesting the relative importance or implying the number of technical features indicated. Thus, features defined by "first," "second," and "third" may explicitly or implicitly include one or more features. In the description of this disclosure, the term "plurality" means two or more, unless expressly and specifically defined otherwise.

[0052] In this disclosure, unless otherwise clearly stated or defined, terms such as "attach," "connect," "connected," and "fixed" should be interpreted broadly, for example, they may be a fixed connection, a removable connection, or an integral connection, a mechanical connection, an electrical connection, or a communication, a direct connection, or an indirect connection through an intermediate medium, or an internal communication between two elements, or an interaction between two elements. For those skilled in the art, the specific meaning of the above terms in this disclosure may be understood according to the specific situation.

[0053] In this disclosure, unless otherwise clearly stated or defined, an expression that a first feature is "above" or "below" a second feature may include cases where the first feature is in direct contact with the second feature, or cases where the first feature and the second feature are not in direct contact but are contacted via another feature between the first feature and the second feature. Furthermore, a first feature being "above," "above," or "on" a second feature includes cases where the first feature is directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher elevation than the second feature. A first feature being "below," "below," or "below" a second feature includes cases where the first feature is directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower elevation than the second feature.

[0054] This description provides many different implementations or examples that can be used to realize the present disclosure. It should be understood that these different implementations or examples are only illustrative and are in no way intended to limit the scope of protection of the present disclosure. Based on the disclosure of the description of the present disclosure, a person skilled in the art can conceive various modifications or replacements. All these modifications or replacements shall be within the scope of protection of the present disclosure. Therefore, the scope of protection of the present disclosure shall be subject to the scope of protection of the claims.

Claims

1. a first optical splitting element including a first input port configured to input an operating signal, a first output port configured to output a main path signal, and a second output port configured to output a first supervisory signal; a second optical dividing element having a 1-in 2-out configuration and an input port of the second optical dividing element connected to the first output port; two waveguide arms, each of one end of the waveguide arms being connected to two output ports of the second optical splitting element, respectively; a bias voltage modulation module configured to apply a bias voltage to the two waveguide arms based on a bias voltage signal; a radio frequency modulation module configured to apply a radio frequency voltage to the two waveguide arms based on a radio frequency signal; a third optical dividing element having a 2-in 3-out structure and two input ports of the third optical dividing element correspondingly connected to the other ends of the two waveguide arms; a fourth optical dividing element having a 1-in-2-out configuration and an input port of the fourth optical dividing element connected to a first output port of the third optical dividing element, the fourth optical dividing element including a third output port configured to output a maximum optical power value and a fourth output port configured to output a second supervisory signal; 1. An electro-optic modulator comprising:

2. When the electro-optical modulator is in an operational state, the optical power input from the first input port is represented by P1, the optical power output from the first output port is represented by P2=P1*(100-A)%, and the optical power output from the second output port is represented by P3=P1*A%, where A% is less than 50%.

2. The electro-optic modulator of claim 1.

3. a fifth optical dividing element having a 1-in-2-out configuration and an input port of the fifth optical dividing element connected to the second output port of the third optical dividing element, the fifth output port being configured to output a third supervisory signal, and a sixth output port being configured to output a fourth supervisory signal. The electro-optic modulator of claim 2 further comprising:

4. A% is a constant value, or A% is determined based on a power ratio of the third supervisory signal to the fourth supervisory signal.

4. The electro-optic modulator of claim 3.

5. a sixth optical dividing element having a 1-in-2-out configuration and an input port of the sixth optical dividing element connected to a third output port of the third optical dividing element, the sixth optical dividing element including a seventh output port configured to output a fifth supervisory signal and an eighth output port configured to output a sixth supervisory signal. The electro-optic modulator of claim 3 further comprising:

6. a feedback module configured to adjust the bias voltage signal output to the bias voltage modulation module based on at least one of the first monitor signal, the second monitor signal, the third monitor signal, the fourth monitor signal, the fifth monitor signal, and the sixth monitor signal. The electro-optic modulator of claim 5 further comprising:

7. the first optical dividing element further includes a second input port configured to input a detection signal; 6. The electro-optic modulator of claim 5.

8. When the electro-optical modulator is in a detection state, the optical power input from the second input port is represented by P0, the optical power output from the first output port is represented by P4=P0*A%, the optical power output from the second output port is represented by P5=P0*(100-A)%, the maximum optical power value output from the third output port is represented by P6, the maximum optical power value output from the fourth output port is represented by P7=P6*A%, and the transmission loss of the electro-optical modulator is represented by C=P6 / P4.

8. The electro-optic modulator of claim 7.

9. the first input port of the first optical dividing element and the second input port of the first optical dividing element have exchange symmetry, and the first output port of the first optical dividing element and the second output port of the first optical dividing element have exchange symmetry.

9. The electro-optic modulator of claim 8.

10. the third output port of the fourth optical dividing element and the fourth output port of the fourth optical dividing element have exchange symmetry.

9. The electro-optic modulator of claim 8.

11. the fifth output port of the fifth optical splitting element and the sixth output port of the fifth optical splitting element have exchange symmetry.

9. The electro-optic modulator of claim 8.

12. the seventh output port of the sixth optical splitting element and the eighth output port of the sixth optical splitting element have exchange symmetry.

9. The electro-optic modulator of claim 8.

13. The first output port of the third optical splitting element is configured to output the maximum optical power value of a coherently amplified signal of two branched optical signals with a phase difference of 2Nπ, where N is 0 or a natural number; the second output port and the third output port of the third optical splitting element are configured to output a set allocation percentage of the maximum optical power value of the coherently amplified signal of two branched optical signals with a phase difference of (2N+1)π, respectively, and the set allocation percentage is greater than 0 and less than 1.

13. An electro-optic modulator according to any one of claims 1 to 12.

14. the third light dividing element has an axially symmetric structure, and the second output port and the third output port of the third light dividing element are symmetrically arranged with respect to the first output port.

13. An electro-optic modulator according to any one of claims 1 to 12.

15. The electro-optical modulator is configured in an NRZ encoding format or a PAM4 encoding format.

13. An electro-optic modulator according to any one of claims 1 to 12.

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