WO2015161477A1 - 一种光信号调制通路、电光调制器以及光发射机 - Google Patents

一种光信号调制通路、电光调制器以及光发射机 Download PDF

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WO2015161477A1
WO2015161477A1 PCT/CN2014/076108 CN2014076108W WO2015161477A1 WO 2015161477 A1 WO2015161477 A1 WO 2015161477A1 CN 2014076108 W CN2014076108 W CN 2014076108W WO 2015161477 A1 WO2015161477 A1 WO 2015161477A1
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optical signal
electrode
optical
electro
input
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PCT/CN2014/076108
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English (en)
French (fr)
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万文通
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华为技术有限公司
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Priority to CN201480000566.2A priority Critical patent/CN105209963B/zh
Priority to PCT/CN2014/076108 priority patent/WO2015161477A1/zh
Publication of WO2015161477A1 publication Critical patent/WO2015161477A1/zh

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    • G—PHYSICS
    • G02—OPTICS
    • G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
    • G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
    • G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour 
    • G02F1/03—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on ceramics or electro-optical crystals, e.g. exhibiting Pockels effect or Kerr effect
    • G02F1/035—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on ceramics or electro-optical crystals, e.g. exhibiting Pockels effect or Kerr effect in an optical waveguide structure

Definitions

  • the present invention relates to the field of optical communication technologies, and in particular, to an optical signal modulation path, an electro-optical modulator, and an optical transmitter. Background technique
  • Electro-optic modulators are based primarily on the fundamental principle of electro-optical crystals and linear electro-optical effects in anisotropic polymers, ie the refractive index of electro-optic crystals varies with the applied applied electric field.
  • the coherent optical communication system more commonly electro-optic modulator is NW? 3 crystal voltage applied electric field produced by Mach Zehnder modulators (Mach-Zehnder Modulator, ⁇ ) , the refractive index crystal ⁇ 3 ⁇ 40 3 significantly changes with applied .
  • the two phase-changed optical signals are combined at the output to obtain an output optical signal ⁇ ).
  • the electro-optic modulator comprises two electrodes, a DC electrode and an RF electrode.
  • the RF electrode is a data modulation port, and receives the amplified analog electrical signal to realize electro-optic modulation.
  • a plurality of RF electrodes are sequentially connected from the optical signal input port to the optical signal output port to form an optical signal modulation path.
  • an electro-optic modulator includes two optical signal modulation paths to implement a push-pull operation. As shown in FIG. 2, the electrodes on the two optical signals between the optical input end and the optical output end of the electro-optic modulator are modulated.
  • each segment of the electrodes is independent of each other, changing the length of each segment of the electrode, so that the optical signal has a phase change after each segment of the electrode transmission, the length of the electrode is different, and the phase of the optical signal changes after passing through the electrode, each The phase change of the final output optical signal of the strip light modulation path electrode is the accumulation of the phase difference under the action of each segment of the electrode on the optical signal.
  • the phase difference of the optical signals of the upper and lower optical signal modulation paths acts as a push-pull.
  • the above electro-optic modulator uses a method of changing the length of each segment of the electrode to change the output light through each segment of the electricity.
  • the size of the phase changed after the pole transmission. This method only changes the length of the electrode.
  • the length of each segment is equal, other parameters are unchanged, if you want to increase the electrode accumulation of each optical signal modulation path.
  • the phase of the optical signal needs to increase the number of electrodes. This will result in a large number of electrodes used in the electro-optic modulator.
  • the length of each electrode is not equal, and other parameters are unchanged, if you want to increase the modulation path of each optical signal.
  • the electrode accumulates the phase of the changed optical signal, and it is necessary to increase the length of one or more of the electrodes, which causes an increase in the electro-optic material consumed by the electrodes in the electro-optic modulator.
  • the electrode of unit length in the electro-optic modulator can change the phase of the optical signal to be a fixed value, and increase the phase of the optical signal changed by the electrode accumulation of each optical signal modulation path by increasing the number of electrodes or changing the length of the electrode.
  • the size increases the size of the optical signal modulation path, which in turn increases the size of the electro-optic modulator, which is not conducive to integration. Summary of the invention
  • embodiments of the present invention provide an optical signal modulation path, an electro-optic modulator, and an optical transmitter.
  • a first aspect of the embodiments of the present invention provides an optical signal modulation path, which is applied to an electro-optic modulator, where the optical signal modulation path includes:
  • At least two electrodes are sequentially connected from the optical signal input port to the optical signal output port, and each electrode is used to change the phase of the input optical signal when the external input electrical signal is at a high level;
  • the at least two electrodes comprise a reference electrode, wherein the reference electrode is an electrode whose input optical signal has the smallest phase when the external input is at a high level, the phase changed by the reference electrode is a reference phase, and the electrode parameters of the other electrodes are The electrode parameters of the reference electrode are different, and the phase of the input optical signal changed by the other electrodes when inputting a high level externally is greater than the reference phase, and the electrode parameters include the material parameters of the electro-optical crystal of the electrode and/or the direction of the electric field and the transmission of the input optical signal. The width of the electric field when the direction is vertical;
  • the material parameter is the product of the cube of the refractive index of the electro-optic crystal of the electrode and the electro-optic coefficient of the electro-optic crystal of the electrode.
  • the phase ratios of the electrodes arranged in the order from the optical signal output port to the optical signal input port are changed: 1:2: ⁇ 2"- 2 :2"- where ⁇ is the number of electrodes.
  • the ratio of the material parameters of the electro-optical crystals of the electrodes arranged in the order from the optical signal output port to the optical signal input port is: I: 2 : 22 : ⁇ : 2 "- 2 : 2 " -1 , where ⁇ The number of electrodes.
  • the direction of action of the electric field is perpendicular to the direction of transmission of the input optical signal, and the ratio of the electric field width of the electrodes arranged in the order from the optical signal output port to the optical signal input port is:
  • the direction of the electric field is perpendicular to the direction in which the input optical signal is transmitted.
  • n is the number of electrodes.
  • the first possible implementation of the first aspect of the embodiment of the invention is combined with the first aspect
  • a fourth possible implementation manner, in a fifth possible implementation manner, the at least two electrodes are sequentially connected to include:
  • the number of electrodes is the same as the bit width of the input electrical signal, and each electrode is connected to one bit of the input electrical signal, wherein the mth electrode from the output end of the optical signal is connected to the lowest position of the input electrical signal.
  • M-bit data where m is a positive integer greater than 0 and less than or equal to the number of electrodes.
  • a second aspect of the embodiments of the present invention provides an electro-optic modulator, where the electro-optic modulator includes: a first optical signal modulation path, where the first optical signal modulation path is a first aspect to a first aspect of the embodiment of the present invention.
  • the first optical signal modulation path is respectively connected to the optical signal input port and the optical signal output port, Each of the first optical signal modulation paths is respectively connected to one bit of data of the input electrical signal; the optical signal input port is configured to receive the optical signal before modulation;
  • the optical signal output port is configured to output an optical signal modulated by the input electrical signal.
  • the electro-optic modulator further includes:
  • the second optical signal modulation path is an optical signal modulation path according to any one of the first aspect to the fifth aspect of the first aspect of the present invention, the second optical signal modulation
  • the two ends of the path are respectively connected to the optical signal input port and the optical signal output port, and each of the second optical signal modulation paths is respectively connected to one bit of the input electrical signal; the respective electrodes on the first optical signal modulation path
  • the direction of the applied electric field of each electrode of the second optical signal modulation path is opposite.
  • the electro-optic modulator further includes:
  • Two DC electrodes which are respectively disposed in the first optical signal modulation path and the optical signal input port of the second optical signal modulation path, are used to adjust the operating voltage of the modulator, thereby adjusting the modulation format of the modulator.
  • a third aspect of the embodiments of the present invention provides an optical transmitter for use in a transmitting end of a coherent optical communication system.
  • the optical transmitter includes:
  • An illuminator, a plurality of amplifier paths, and an electro-optic modulator according to any one of the second aspect of the invention to the second possible implementation of the second aspect;
  • the encoder encodes the input data and converts the input electrical signal into an output of the plurality of amplifiers
  • the number of the amplifier paths is equal to the number of electrodes on the signal modulation path in the electro-optic modulator, and each of the amplifier paths is for amplifying one bit of data of the input electrical signal and outputting to the electro-optic modulator An electrode connected to it.
  • the optical transmitter further includes: a digital-to-analog converter, the digital-to-analog converter performs digital-to-analog conversion on the input electrical signal received from the encoder After that, it is output to the plurality of amplifiers.
  • the embodiment of the present invention provides an optical signal modulation path, an electro-optic modulator, and an optical transmitter.
  • the optical signal modulation path includes: at least two electrodes are sequentially connected from the optical signal input port to the optical signal output port, and each electrode is connected Changing the phase of the input optical signal when the external input electrical signal is at a high level; the at least two electrodes include a reference electrode, and the reference electrode is an electrode whose phase of the input optical signal is changed to be the smallest when the external input is at a high level, the reference The phase changed by the electrode is the reference phase, and the electrode parameters of the other electrodes are different from the electrode parameters of the reference electrode, and the phase of the input optical signal changed by the other electrodes when inputting the high level externally is greater than the reference phase, and the electrode parameters include the electrode.
  • the refractive index material parameter of the electro-optic crystal and/or the electric field width when the electric field acts in the transverse direction are different from those of the electro-optical crystal of the reference electrode, and the phase of the input optical signal changed by the other electrodes is larger than that of the reference electrode.
  • the phase of the changed input optical signal when the space occupied by the entire optical signal modulation path is fixed, causes the electrodes on the optical signal modulation path to be connected to the high level, and is increased compared with the reference electrode only on the optical signal modulation path.
  • the cumulative amount of the phase of the input optical signal that can be changed by the entire optical signal modulation path can be increased without increasing the number of electrodes or increasing the length of the individual electrodes.
  • the optical signal modulation path provided by the embodiment of the invention has small size, is convenient for integration, and has high flexibility.
  • FIG. 1 is a schematic diagram of a structure of an MZM in the prior art
  • FIG. 2 is a schematic structural view of an electro-optic modulator in the prior art
  • Figure 3 (a) is a vertical schematic view of the direction of action of the electric field
  • Figure 3 (b) is a horizontal schematic view of the direction of action of the electric field
  • FIG. 4 is a schematic structural view of an embodiment of an optical signal modulation path according to the present invention.
  • 5 is a schematic structural view of Embodiment 6 of an electro-optic modulator according to the present invention;
  • FIG. 6 is a schematic structural view of a seventh embodiment of an electro-optic modulator according to the present invention.
  • FIG. 7 is a schematic structural view of an eighth embodiment of an optical transmitter according to the present invention. detailed description
  • An embodiment of the present invention provides an electro-optic modulator and an electro-optical modulation method, in order to provide an implementation of increasing the phase of the optical signal that can be changed by the entire optical signal modulation path.
  • the preferred embodiments of the present invention are described with reference to the accompanying drawings, and the preferred embodiments described herein are intended to illustrate and explain the invention. And in the case of no conflict, the embodiments in the present application and the features in the embodiments can be combined with each other.
  • the first type is shown in Fig. 3 (a).
  • the direction of the applied electric field of the electrode is parallel to the direction of propagation of the optical signal in the electrode. At this time, the direction of the electric field is longitudinal, and the optical signal changed by the single electrode is calculated by the formula (1).
  • N is the refractive index of the electro-optic crystal
  • V is the voltage of the applied electric field
  • Z is the length of the electrode
  • d is the electric field width.
  • the direction of the applied electric field may be greater than 0 with the direction of propagation of the optical signal in the electrode. And less than 90.
  • the angle of the applied electric field can be divided into a component parallel to the propagation direction of the optical signal in the electrode and a component perpendicular to the propagation direction of the optical signal in the electrode.
  • the phase change of the corresponding optical signal is the phase changed by the electric field component parallel to the propagation direction of the optical signal in the electrode, and the sum of the electric field components perpendicular to the propagation direction of the optical signal in the electrode.
  • the prior art changes the length of the electrode Z to change the change of the electrode to the optical signal.
  • the magnitude of the phase therefore, in the prior art, the direction of the applied external electric field is lateral, since changing the length of the electrode does not change the magnitude of the phase changed by the electrode to the optical signal when the direction of the applied electric field is longitudinal.
  • only the phase length Z of the optical signal is used to subdivide and quantize the phase changed by the optical signal modulation path.
  • One method is that the length of each electrode on the optical signal modulation path is the same and changed.
  • the phase of the optical signal is the same, and the phase ⁇ is changed cumulatively to realize subdivision and quantization of the phase uniformity in the optical signal modulation path.
  • the length of each electrode on the optical signal modulation path is different, and the changed light
  • the phase of the signal is also different, and the phase is changed cumulatively to realize the subdivision quantization of the phase unevenness on the optical signal modulation path.
  • the subdivision quantization of the phase ⁇ is realized only by changing the length I of the electrode.
  • the direction of the applied electric field is vertical, or the space occupied by the optical signal modulation path is constant, the subdivision quantization cannot be realized by changing the length ⁇ .
  • other implementations for subdividing the phase are not given.
  • the phase-related electrode parameters have the refractive index of the electro-optic crystal in addition to the electrode length, the linear electro-optic coefficient plus the electric field width d in the lateral direction and the applied electric field voltage.
  • V The following embodiments of the present invention mainly discuss different material parameters of the electro-optic crystal in the electrode, or different electric field widths when the applied electric field direction is lateral, or different material parameters and different electric field widths d when the applied electric field direction is lateral.
  • the material parameters are different, the direction of the applied electric field is different, and the electric field width ⁇ / is different when the applied electric field direction is the lateral direction, the subdivision quantization of the phase ⁇ on the modulation path of the optical signal is realized, so as to achieve no increase in the number of electrodes or change Under the premise of the length of the electrode, the magnitude of the phase changed by the entire optical signal modulation path for the accumulation of the optical signal is increased.
  • Embodiment 1 of an optical signal modulation path according to the present invention is applied to an electro-optic modulator, and the optical signal modulation path includes:
  • At least two electrodes are sequentially connected from the optical signal input port to the optical signal output port, and each of the electrodes is used to change the phase of the input optical signal when the external input electrical signal is at a high level.
  • the optical signal modulation path shown in FIG. 4 is connected to the optical signal input port at the left end and to the optical signal output port at the right end, from the optical signal output port of the optical signal modulation path to the optical signal input.
  • Port, electrode ⁇ . , electrode, electrode ⁇ 2 , ..., electrode - a total of ⁇ electrodes are sequentially connected to form an optical signal modulation path.
  • the number of electrodes is the same as the bit width of the input electrical signal, and each electrode is connected to one bit of the input electrical signal, wherein the mth electrode from the output end of the optical signal is accessed from The mth bit data from the lowest bit of the electrical signal is input, where m is a positive integer greater than 0 and less than or equal to the number of electrodes.
  • each electrode connected in turn on the optical signal modulation path each electrode is connected to one bit of the input electrical signal, from the output port of the optical signal to the input port of the optical signal, and sequentially accesses the lowest bit to the highest bit of the input electrical signal .
  • the electrode ⁇ As shown in Figure 4, the electrode ⁇ . The lowest bit of the input signal is connected, the electrode is connected to the second bit of the input signal, the electrode ⁇ 3 is connected to the third bit of the input signal, and so on, and the electrode is connected to the nth bit (the highest bit) of the input signal.
  • Each electrode changes the phase of the input optical signal when the input electrical signal to which it is connected is high.
  • the magnitude of the phase of the optical signal changed by the entire optical signal modulation path is the sum of the phases of the optical signals that are changed by the respective electrodes using the connected electrical signals.
  • the at least two electrodes comprise a reference electrode, wherein the reference electrode is an electrode whose input optical signal has the smallest phase when the external input is at a high level, the phase changed by the reference electrode is a reference phase, and the electrode parameters of the other electrodes are The electrode parameters of the reference electrode are different, and the phase of the input optical signal changed by the other electrodes when inputting a high level externally is greater than the reference phase, and the electrode parameters include the material parameters of the electro-optical crystal of the electrode and/or the direction of the electric field and the transmission of the input optical signal. The width of the electric field when the direction is vertical.
  • the material parameter is the product of the cube of the refractive index of the electro-optic crystal of the electrode and the electro-optic coefficient of the electro-optic crystal of the electrode.
  • the phase of the input optical signal that is changed when the reference electrode is input to the external high level is the smallest. As shown in Fig. 4, the electrode ⁇ is used. For the example of the reference electrode, when the electrical signal to which the electrode is connected is at a high level, the phase of the changed optical signal is %.
  • electrode electrodes ⁇ 2 , ..., electrodes ⁇ RON — different from the electrode parameters of the electrode ⁇ , and, the electrodes, the electrodes ⁇ 2 , ..., when the connected electrical signal is at a high level,
  • the phase of the changed optical signal, %, ⁇ is greater than %.
  • the electrodes, the electrodes ⁇ 2 , ..., the electrodes are connected to the electrical signals.
  • the phase of the changed optical signal ⁇ , ⁇ is greater than %.
  • the phase of the changed optical signal is only greater than, but there is no regular proportional relationship between %, ⁇ ;
  • the second case the electrode, the electrode ⁇ 2 , ..., the electrode, when the connected electrical signal is at a high level, the phase of the changed optical signal, i is not greater than, and, 2 , .izie-i
  • the proportional relationship between the two is 2"- 1 : 2"- 2 : ⁇ 2:1;
  • the third case the electrode, the electrode ⁇ 2 , ..., the phase of the changed optical signal when the connected electrical signal is at a high level, 1 is not only greater than ⁇ .
  • the ratio between ⁇ , 2, ⁇ is 1: 2 : ⁇ 2"- 2 : 2"- 1 .
  • the change of the phase of the input optical signal by the electrode of the optical signal modulation path is not limited to the above three cases, and the electrode located in the middle of the optical signal modulation path may be changed when the connected electrical signal is at a high level.
  • the phase of the input optical signal is the largest, and when the electrical signal connected by the electrodes on both sides of the intermediate phase is at a high level, the phase of the changed input optical signal is sequentially decreased; or the electrode located in the middle of the optical signal modulation path is in the When the connected electrical signal is at a high level, the phase of the changed input optical signal is the smallest, and when the electrical signal connected by the electrodes on both sides of the intermediate phase is at a high level, the phase of the changed input optical signal sequentially increases.
  • the electrodes of the same length on the optical signal modulation path are different from the electrode parameters of the reference electrode and are changed when the connected electrical signal is at a high level.
  • the phase of the input optical signal is greater than the reference phase, and is not repeated here.
  • the third case is generally used, and no special complex coding is performed outside the electro-optic modulator to obtain a specific mapping relationship between the input electric signal and the phase changed by the output optical signal: when the optical signal When the electrodes on the modulation path are at a high level, the phase ratios of the electrodes arranged in the order from the optical signal output port to the optical signal input port are changed: I: 2 : ... 2 "— 2 : 2 " — where ⁇ is the number of electrodes.
  • the electrodes on the optical signal modulation path are at a high level when the connected electrical signals are high, the subdivision quantization of the phase on the optical signal modulation path is achieved in accordance with the natural coding.
  • Regularity, ⁇ ⁇ 0 + ⁇ ⁇ + ⁇ 2 - ⁇ h ⁇ ⁇ _.
  • the optical signal modulates the individual electrodes ⁇ on the path.
  • the electrode parameters of the electrode ⁇ , the electrode ⁇ 2 , ..., the electrode ⁇ resort — are different, and the electrode parameters include the material parameter of the electro-optic crystal of the electrode and/or the electric field when the direction of the electric field is perpendicular to the direction of transmission of the input optical signal. Width, according to the arrangement order from the optical signal output port to the optical signal input port, the magnitude of the change of the phase of the optical signal by a single electrode on the optical signal modulation path is multiplied by ( ⁇ : ⁇ : ⁇ :... ⁇ .
  • the subdivision quantization of the phase on the modulation path of the optical signal conforms to the law of natural coding. In this case, no additional complex coding of the input electrical signal is required, and a specific mapping relationship between the phase of the input electrical signal and the output optical signal can be obtained. .
  • the material parameter is the product of the cube of the refractive index of the electro-optic crystal of the electrode and the electro-optic coefficient of the electro-optic crystal of the electrode.
  • At least two electrodes are sequentially connected from the optical signal input port to the optical signal output port, each electrode for changing a phase of the input optical signal when the external input electrical signal is at a high level; the at least two electrodes including a reference electrode,
  • the reference electrode is an electrode whose input optical signal has the smallest phase when the external input is high level, the phase changed by the reference electrode is the reference phase, the electrode parameters of the other electrodes are different from the electrode parameters of the reference electrode, and the other electrodes are externally input.
  • the phase of the input optical signal that is changed at a high level is greater than the reference phase
  • the electrode parameters include a refractive index material parameter of the electro-optic crystal of the electrode and/or an electric field width when the electric field acts in a lateral direction.
  • the material parameters of the electro-optic crystal of the electrode other than the reference electrode and the reference electrode of the optical signal modulation path are different from those of the electro-optical crystal of the reference electrode, and the phase of the input optical signal changed by the other electrodes is larger than that of the reference electrode.
  • the phase of the changed input optical signal when the space occupied by the entire optical signal modulation path is fixed, causes the electrodes on the optical signal modulation path to be connected to the high level, and is increased compared with the reference electrode only on the optical signal modulation path.
  • the optical signal modulation path is in accordance with the optical signal.
  • the phase ratio of the electrode arranged in the order of the output port to the optical signal input port to the input optical signal is: I: 2 :... 2
  • Embodiment 2 to Embodiment 4 are modulated by an optical signal composed of three electrodes connected
  • the optical signal modulation path formed by the connection of other electrodes is similar, and is not repeated here.
  • the material parameters of the electro-optical crystals of the respective electrodes on the optical signal modulation path are different, and the subdivision quantization of the phase changed by the optical signal modulation path is realized:
  • At least two electrodes are sequentially connected, and the material parameters of the electro-optical crystals of the respective electrodes are different.
  • the ratio of the material parameters of the electro-optical crystals of the electrodes arranged in the order from the optical signal output port to the optical signal input port is: ⁇ ⁇ ⁇ 2 : ⁇ "- 2 ⁇ "- 1 , where ⁇ is the number of electrodes.
  • the material parameter is the product of the cube of the refractive index of the electro-optic crystal of the electrode and the electro-optic coefficient of the electro-optic crystal of the electrode.
  • the phase changed by the electrode is related to the refractive index N of the electro-optic crystal of the electrode and the electro-optic coefficient r of the electro-optic crystal of the electrode, that is, each The refractive index N and the electro-optic coefficient r of the electro-optical crystal of the electrode are different, and the magnitude of the change of the phase of the optical signal by each electrode is different. Since the phase is proportional to the product of the cube of the refractive index N of the electro-optic crystal and the electro-optic coefficient r, the respective electrodes ⁇ on the optical signal modulation path are provided.
  • the subdivision quantization of the phase on the optical signal modulation path conforms to the natural coding law.
  • the electro-optic crystal has a refractive index of N.
  • the phase change of the optical signal is, for example, an optical signal modulation path composed of three electrodes connected, and three electrodes ⁇ are listed in Table 1. The refractive indices of , and 2 , and the magnitude of the phase changed by each electrode to the optical signal.
  • the refractive index of the electrode is different.
  • the electrode material parameter changes the phase size.
  • a r N 3 1 ⁇ 2 0 can be seen in Table 1, electrode B.
  • the magnitude of the phase of the changed optical signal is such that the phase of the optical signal changed by the electrode is 2, and the phase of the optical signal changed by the electrode B 2 is 1 ⁇ 2.
  • the number of electrodes is the same as the bit width of the input electrical signal, and each electrode is connected to one bit of the input electrical signal, wherein the mth electrode from the output end of the optical signal is connected to the lowest position of the input electrical signal.
  • M-bit data where m is a positive integer greater than 0 and less than or equal to the number of electrodes.
  • each electrode connected in turn on the optical signal modulation path each electrode is connected to one bit of the input electrical signal, from the output port of the optical signal to the input port of the optical signal, and sequentially accesses the lowest bit to the highest bit of the input electrical signal .
  • the electrode ⁇ As shown in Figure 4, the electrode ⁇ . The lowest bit of the input signal is connected, the electrode is connected to the second bit of the input signal, the electrode ⁇ 3 is connected to the third bit of the input signal, and so on, and the electrode is connected to the nth bit (the highest bit) of the input signal.
  • the magnitude of the phase of the optical signal changed by the entire optical signal modulation path is the sum of the phases of the optical signals that are changed by the received electrical signals for the respective electrodes.
  • Table 2 is a comparison table of the encoding of the input electrical signal and the phase change of the optical signal at the output relative to the input. It can be seen from the contents in Table 2 that after the optical signal is modulated by the optical signal modulation path, the phase changed at the output end with respect to the input end conforms to the natural coding law. Table 2 Input electrical signal coding and phase of the optical signal changed at the output relative to the input. Input electrical signal coding
  • changing the refractive index of the electro-optic crystal of the electrode can be achieved by adding metal impurities or metal compounds to the electro-optic crystal of the electrode.
  • different concentrations of iron or magnesium oxide can be added to the electro-optic crystal to realize electro-optic A change in the refractive index of the crystal.
  • the refractive index ⁇ and the electro-optical coefficient r of the electro-optic crystal of each electrode on the optical signal modulation path are different, and the refractive index of the electrode to the input optical signal is different, so the phase of the change of the optical signal is also different.
  • the phase of the optical signal of each electrode arranged from the optical signal output port to the optical signal input port can also be changed according to the natural coding law; meanwhile, due to the difference in material parameters of the electro-optical crystal of the electrode, Each of the electrodes arranged by the optical signal output port to the optical signal input port increases the phase change of the optical signal by a multiple, and the number of electrodes required to change the phase of the same magnitude of the optical signal is less than that of the prior art, and the number of electrodes is reduced.
  • At least two electrodes are sequentially connected, and electric field widths of the respective electrodes are different, and the electric field is applied
  • the ratio of the electric field width when the direction of the electric field of the electrodes arranged in the order from the optical signal output port to the optical signal input port is lateral:
  • n is the number of electrodes.
  • the phase changed by the electrode is related to the electric field width d of the applied electric field.
  • the electric field width d of the electrode is different.
  • the phase of the optical signal changed by the electrode is different. Since the phase is inversely proportional to the electric field width ⁇ / , the respective electrodes ⁇ on the optical signal modulation path are set.
  • the ratio of the electric field width of ⁇ ⁇ ⁇ 2 ⁇ tile ⁇ i is: ⁇ : : ⁇ :... ⁇ ⁇ : ⁇ :...: ⁇ , realizing each electrode ⁇ , , ⁇ 1, ⁇ 2...
  • the applied electric field may also have a certain angle with the direction of the input optical signal, but has a component in a direction perpendicular to the optical signal transmission direction.
  • the electric field width is such that the phase change of the optical signal is, for example, an optical signal modulation path composed of three electrodes connected, and three electrodes ⁇ are listed in Table 3. , the electric field width of £! and £ 2 , and the magnitude of the phase changed by each electrode to the optical signal.
  • the electrode is ⁇ .
  • the magnitude of the phase of the changed optical signal is such that the phase of the optical signal changed by the electrode is 2 % , and the phase of the optical signal changed by the electrode B 2 is 1 ⁇ 2. , by setting the electrode ⁇ . Different from the B 2 electric field width, the phase of the changed phase on the optical signal modulation path is subdivided and quantized in accordance with the natural law to make the electrode B. The magnitudes of the phases of the optical signals changed by Bi, B 2 are multiplied.
  • the number of electrodes is the same as the bit width of the input electrical signal, and each electrode is connected to one bit of the input electrical signal, wherein the mth electrode from the optical signal output terminal is connected to the lowest bit of the input electrical signal
  • the mth bit data where m is a positive integer greater than 0 and less than or equal to the number of electrodes.
  • Each electrode connected in turn on the optical signal modulation path each electrode is connected to one bit of the input electrical signal, from the output port of the optical signal to the input port of the optical signal, and sequentially accesses the lowest bit to the highest bit of the input electrical signal .
  • the electrode ⁇ As shown in Figure 4, the electrode ⁇ .
  • the lowest bit of the input signal is connected, the electrode is connected to the second bit of the input signal, the electrode ⁇ 3 is connected to the third bit of the input signal, and so on, and the electrode is connected to the nth bit (the highest bit) of the input signal.
  • the magnitude of the phase of the optical signal changed by the entire optical signal modulation path is the sum of the phases of the optical signals that are changed by the received electrical signals for the respective electrodes.
  • the code of the input electrical signal and the phase of the optical signal changed at the output relative to the input segment are the same as in Table 2.
  • the optical signal is modulated by the optical signal modulation path, and the output is opposite to the input terminal.
  • the changed phase conforms to the natural coding law.
  • the third embodiment has the following beneficial effects:
  • Embodiment 4 When changing the phase of the optical signal, it is only necessary to change the applied electric field width of the electrode, and the operation is simple. It is not necessary to change the length of the electrode or increase the number of electrodes, so that the phase changed at the output end relative to the input end conforms to the natural coding law. .
  • Embodiment 4 When changing the phase of the optical signal, it is only necessary to change the applied electric field width of the electrode, and the operation is simple. It is not necessary to change the length of the electrode or increase the number of electrodes, so that the phase changed at the output end relative to the input end conforms to the natural coding law. .
  • the material parameters of the electro-optic crystal of each electrode on the optical signal modulation path and the electric field width when the direction of the electric field is perpendicular to the optical signal transmission direction are different, and the phase division of the phase changed by the optical signal modulation path is realized:
  • At least two electrodes are sequentially connected, and the material parameters and the electric field width of the respective electrodes are different.
  • the ratio of the material parameters of the electro-optical crystals of the electrodes arranged in the order from the optical signal output port to the optical signal input port is:
  • the direction of the electric field is perpendicular to the direction of transmission of the input optical signal.
  • the ratio of the electric field width when the direction of the electric field of the electrode arranged in the order from the optical signal output port to the optical signal input port is lateral: d 0 ⁇ : d 2 : ⁇ ⁇ — 1 ; where ⁇ is the number of electrodes.
  • the electro-optic crystal has a refractive index of N.
  • the electric field width is, the phase change of the optical signal is as an example, and the optical signal modulation path composed of four electrodes is connected as an example.
  • Table 4 lists the refractive indices of the four electrodes ⁇ ⁇ 2 and the electric field width and each Electrode pair optical The size of the phase changed by the number. Table 4 refractive index and electric field width are different
  • the electrode is ⁇ .
  • the magnitude of the phase of the changed optical signal is %
  • the phase of the optical signal changed by the electrode is 2 %
  • the phase of the optical signal changed by the electrode B 2 is 1 ⁇ 2.
  • the magnitude of the phase of the optical signal changed by the electrode B 3 is 8, by providing the electrode B.
  • the refractive indices and electric field widths of the different electro-optic crystals of Bi, B 2 and B 3 enable subdivision and quantization of the phase changed on the modulation path of the optical signal in accordance with the natural law, so that the electrode B.
  • the magnitudes of the phases of the optical signals changed by Bi, B 2 and B 3 are multiplied.
  • the number of electrodes is the same as the bit width of the input electrical signal, and each electrode is connected to one bit of the input electrical signal, wherein the mth electrode from the output end of the optical signal is connected to the lowest position of the input electrical signal.
  • M-bit data where m is a positive integer greater than 0 and less than or equal to the number of electrodes.
  • each electrode connected in turn on the optical signal modulation path each electrode is connected to one bit of the input electrical signal, from the output port of the optical signal to the input port of the optical signal, and sequentially accesses the lowest bit to the highest bit of the input electrical signal .
  • the electrode ⁇ As shown in Figure 4, the electrode ⁇ . The lowest bit of the input signal is connected, the electrode 2 is connected to the second bit of the input signal, the electrode ⁇ 3 is connected to the third bit of the input signal, and so on, and the electrode is connected to the nth bit (the highest bit) of the input signal.
  • the magnitude of the phase of the optical signal changed by the entire optical signal modulation path is the sum of the phases of the optical signals that are changed by the received electrical signals for the respective electrodes.
  • Table 5 shows the coding of the input electrical signal and the phase of the optical signal changed at the output relative to the input. Bit comparison table. It can be seen from the content in Table 5 that after the optical signal is modulated by the optical signal modulation path, the phase changed at the output end with respect to the input end conforms to the natural coding law. Table 5 Input electrical signal coding and phase input electrical signal coding of the optical signal changed at the output relative to the input
  • the two parameters of the refractive index and the electric field width jointly control the phase of the optical signal changed by the electrode, and have the following advantages:
  • the electrode parameters include the direction of the electric field, the ratio of the electrode length of the electrode to the electric field width, and the material parameters of the electro-optic crystal, and the subdivision of the phase changed by the optical signal modulation path is realized. Quantification:
  • the phase change of the electrode to the optical signal is independent of the length of the electrode and the width of the electric field.
  • At least two electrodes are sequentially connected, and the ratio of the electrode length of the electrodes of each electrode to the electric field width, the direction of the electric field action, and the material parameters of the electro-optic crystal are such that the phase of the optical signal changed by each electrode follows the output port of the optical signal.
  • the order to the optical signal input port conforms to the law of natural coding.
  • Table 6 shows the ratio of the electrode length to the electric field width, the direction of the electric field, and the refractive index.
  • the electrode ⁇ As can be seen from Table 6, the electrode ⁇ . And the refractive index of the electrode ⁇ , the ratio of the electrode length to the electric field width, the two parameters are the same, due to the electrode ⁇ .
  • the direction of the electric field is longitudinal, and the phase of the optical signal changed by the electrode is independent of the length of the electrode and the width of the electric field, and therefore, the electrode ⁇ .
  • the phase of the changed optical signal is instead of 2.
  • the phase of the optical signal changed by the electrode is related to the length of the electrode and the width of the electric field.
  • the ratio of the length of the electrode to the width of the electric field is the electrode ⁇
  • the phase of the optical signal changed by the electrode ⁇ 2 is twice the size of the optical signal changed by the electrode.
  • the phase of the changed phase of the optical signal modulation path is subdivided and quantified according to the natural law, so that the electrode B Q The phase of the optical signal changed by Bi, B 2 and B 3 is large Small increments.
  • the number of electrodes is the same as the number of bits of the input electrical signal, and each electrode is connected to one bit of the input electrical signal, wherein the mth electrode from the output end of the optical signal is connected to the input electrical
  • each electrode connected in turn on the optical signal modulation path each electrode is connected to one bit of the input electrical signal, from the output port of the optical signal to the input port of the optical signal, and sequentially accesses the lowest bit to the highest bit of the input electrical signal .
  • the electrode ⁇ As shown in Figure 4, the electrode ⁇ . The lowest bit of the input signal is connected, the electrode 2 is connected to the second bit of the input signal, the electrode ⁇ 3 is connected to the third bit of the input signal, and so on, and the electrode is connected to the nth bit (the highest bit) of the input signal.
  • the magnitude of the phase of the optical signal changed by the entire optical signal modulation path is the sum of the phases of the optical signals that are changed by the received electrical signals for the respective electrodes.
  • the code of the input electrical signal and the phase of the optical signal changed at the output relative to the input segment are the same as in Table 5.
  • the optical signal is modulated by the optical signal modulation path, and the output is opposite to the input terminal.
  • the changed phase conforms to the natural coding law.
  • the electrode parameters also include the direction of action of the electric field.
  • the parameters of the electrode can be flexibly set to achieve the respective electrodes on the optical signal modulation path, and the phase changed at the output end relative to the input end conforms to the natural coding law.
  • FIG. 5 is a schematic structural diagram of Embodiment 6 of an electro-optic modulator according to the present invention, where the electro-optic modulator includes:
  • the first optical signal modulation path 501 is an optical signal modulation path according to any one of Embodiments 1 to 5 of the present invention.
  • the two ends of the first optical signal modulation path are respectively associated with the optical signal.
  • the input port and the optical signal output port are connected, and each of the first optical signal modulation paths is respectively connected to one bit of the input electrical signal.
  • the optical signal input port 502 is configured to receive the optical signal before modulation.
  • the optical signal output port 503 is configured to output an optical signal modulated by the input electrical signal.
  • the photoelectric modulator has only one optical signal modulation path, and the optical signal is transmitted from the input port of the electro-optic modulator to the first optical signal modulation path, and the first optical signal modulation path uses the input electrical signal to modulate the optical signal.
  • the optical signal output port output of the electro-optic modulator.
  • Embodiment 7 of an electro-optic modulator according to the present invention, where the electro-optic modulator includes:
  • the first optical signal modulation path 501, the first optical signal modulation path is the optical signal modulation according to any one of Embodiments 1 to 5, and the first optical signal modulation path is respectively connected to the optical signal input port. And the optical signal output port is connected, and each of the first optical signal modulation paths is respectively connected to one bit of the data path of the input electrical signal.
  • the second optical signal modulation path 601 is the optical signal modulation path according to any one of Embodiments 1 to 5, and the two ends of the second optical signal modulation path and the optical signal input port are respectively And the optical signal output port is connected, and each of the electrodes in the second optical signal modulation path is respectively connected to one bit of the input electrical signal.
  • the optical signal input port 502 is configured to receive the optical signal before modulation.
  • the optical signal output port 503 is configured to output an optical signal modulated by the input electrical signal.
  • the electro-optic modulator further includes:
  • Two DC electrodes 602 and 603, which are respectively disposed in the first optical signal modulation path and the optical signal input port of the second optical signal modulation path, for adjusting the operating voltage of the modulator, thereby adjusting the modulator Modulation format.
  • the DC electrodes 602 and 603 are mainly used to adjust the operating point of the operating voltage or the operating current on the first optical signal modulation path and the second optical signal modulation path, respectively, for adjusting the modulation format of the electro-optic modulator.
  • first optical signal modulation path and the second optical signal modulation path may be changed by adding the positive and negative directions of the electric field voltage or changing the positive and negative of the input electric signal to realize the first optical signal modulation path and the second optical signal path.
  • the opposite phase of the change of the optical signal enables the push-pull action of the electro-optic modulator.
  • the first optical signal modulation path in the electro-optic modulator and the phase of the electrode pair in the second optical signal modulation path may be the same or different.
  • the line is specifically limited, and different quantization methods can also be used, and the push-pull operation mode is not realized.
  • FIG. 7 is a schematic structural diagram of an eighth embodiment of an optical transmitter according to the present invention, which is applied to a transmitting end of a coherent optical communication system, where the optical transmitter includes:
  • Encoder 701 a plurality of amplifier paths F. ⁇ F 1 and Do D ⁇ and an electro-optic modulator 702 as described in Embodiments 6 through 7.
  • the encoder 701 encodes the input data into an input electrical signal and outputs it to a plurality of amplifier paths;
  • the number of amplifier paths is the same as the electrode B on a signal modulation path in the electro-optic modulator 701.
  • the number of ⁇ : is equal, and each of the amplifier paths is used to amplify one bit of the input electrical signal and output it to an electrode connected to the electro-optic modulator.
  • the optical transmitter further includes:
  • a digital-to-analog converter that performs digital-to-analog conversion on the input electrical signal received from the encoder, and outputs the same to the plurality of amplifiers Fo F ⁇ and

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Abstract

一种光信号调制通路、电光调制器以及光发射机，光信号调制通路上除基准电极以外的其他电极与基准电极的电光晶体的材料参数和/或在电场作用方向为横向时的电场宽度不同，其他电极所改变的输入光信号的相位大于基准电极所改变的输入光信号的相位，在整个光信号调制通路所占空间一定的情况下，使得光信号调制通路上的电极都接入高电平时，与光信号调制通路上只有基准电极相比，增大所改变的输入光信号的相位大小，无需增加电极的个数或者增加单个电极的长度，即可实现增大整个光信号调制通路所能改变的输入光信号的相位的累计大小。

Description

一种光信号调制通路、 电光调制器以及光发射机 技术领域
本发明涉及光通信技术领域， 特别是涉及一种光信号调制通路、 电光调 制器以及光发射机。 背景技术
电光调制器主要基于电光晶体以及各向异性聚合物中的线性电光效应 的基本原理， 即电光晶体的折射率会随着所施加的外加电场而变化。 目前， 相干光通信系统中比较常用的电光调制器是 NW?3晶体制作的马赫增德尔 调制器（Mach-Zehnder Modulator, ΜΖΜ)， Λ¾03晶体的折射率明显随施加 的外加电场的电压而改变。 如图 1所示的 ΜΖΜ的结构， \¾03晶体在上下 两个电压信号 ^ (0和^2 (0的作用下折射率发生改变， 光信号 Ein ( 分成上下 两路入射至 LiNb03晶体中，输出的两路光信号相位随 LiNb03晶体折射率的改 变分别改变 和 ( )。 两束改变相位的光信号在输出端合路后获得输出 光信号 Κ)。
电光调制器中包括两种电极， 一种直流电极， 一种射频电极， 射频电 极是数据调制端口， 接收放大后的模拟电信号， 实现电光调制。 多个射频 电极从光信号输入端口至光信号输出端口依次相连形成一条光信号调制通 路。通常一个电光调制器包括两条光信号调制通路来实现推挽的工作方式， 如图 2所示， 将电光调制器的光输入端与光输出端之间的两条光信号调制 通路上的电极分成多段， 每段电极相互独立， 改变每段电极的长度， 从而 光信号经过每段电极传输后都有一个相位的变化， 电极长度不同， 光信号 经过电极后所改变的相位的大小不同， 每条光信号调制通路电极最终输出 光信号相位的变化就是每段电极对光信号共同作用下的相位差的累加。 在 调制器的输出端， 上下两条光信号调制通路的光信号的相位差反向起到推 挽的作用。
本领域技术人员釆用上述电光调制器实现对光信号的相位调制时， 发 现有如下缺点：
上述电光调制器釆用改变每段电极长度的方法来改变输出光经每段电 极传输后所改变的相位的大小， 这种方式只改变了电极的长度， 当每段电 极长度相等时， 其它参数不变的情况下， 若想增加每条光信号调制通路的 电极累计所改变的光信号相位， 需要增加电极的个数， 这样会导致电光调 制器所用的电极数量很多； 当每段电极长度不等时， 其它参数不变的情况 下， 若想增加每条光信号调制通路的电极累计所改变的光信号相位， 需要 增加某个或是多个电极的长度， 这样会导致电光调制器中电极所耗费的电 光材料增加。 上述电光调制器中单位长度的电极可以改变光信号的相位是 一个定值， 通过增加电极的个数或改变电极的长度来实现增加每条光信号 调制通路的电极累计所改变的光信号相位的大小， 会增加光信号调制通路 的尺寸， 进而增加电光调制器的尺寸， 不利于集成。 发明内容
有鉴于此， 本发明实施例提供了一种光信号调制通路、 电光调制器以 及光发射机。
本发明实施例第一方面提供一种光信号调制通路，应用于电光调制器， 所述光信号调制通路包括：
至少两个电极从光信号输入端口至光信号输出端口依次相连， 每个电 极用于在外部输入电信号为高电平时改变输入光信号的相位；
所述至少两个电极包括基准电极， 所述基准电极是外部输入高电平时 所改变输入光信号相位最小的电极， 所述基准电极所改变的相位为基准相 位， 其他电极的电极参数与所述基准电极的电极参数不同， 其他电极在外 部输入高电平时所改变的输入光信号的相位大于基准相位， 所述电极参数 包括电极的电光晶体的材料参数和 /或电场作用方向与输入光信号传输方 向垂直时的电场宽度；
其中， 所述材料参数为电极的电光晶体的折射率的立方与电极的电光 晶体的电光系数的乘积。
本发明实施例第一方面的第一种可能的实现方式中：
所有电极所接入的外部电信号都为高电平时， 按照从光信号输出端口 至光信号输入端口的顺序所排列的电极对输入光信号所改变的相位比为： 1:2:···2"- 2 :2"- 其中， η为电极的个数。
结合本发明实施例第一方面的第一种可能的实现方式， 在第二种可能 的实现方式中：
按照从光信号输出端口至光信号输入端口的顺序所排列的电极的电光 晶体的材料参数的比为： I:2:22 :···:2"—2 :2"—1 , 其中， η为电极的个数。
结合本发明实施例第一方面的第一种可能的实现方式， 在第三种可能 的实现方式中：
所述电场作用方向与输入光信号传输方向垂直， 按照从光信号输出端 口至光信号输入端口 的顺序所排列的电极的电场宽度的比为：
1：!：!：... 1 , 其中， η为电极的个数。
2 4 2"- 1
本发明实施例第一方面的第四种可能的实现方式中：
电 场 作 用 方 向 与 输 入 光 信 号 传 输 方 向 垂 直 ，
^:^:^:•••:^^ = 1:2:4:…： 2"， 其中， rQ :r1 :r2 :…^分别表示电极 的电光晶体的电光系数， d0 :d d2：… 分别表示电极的电场宽度，
Νϋ Ν\： N2 :. N„— i分别表示电极的电光晶体的折射率， n为电极的个数。 结合本发明实施例第一方面的第一种可能的实现方式至第一方面第四 种可能的实现方式， 在第五种可能的实现方式中， 至少两个电极依次相连 包括：
电极的个数与输入电信号的位宽相同， 每个电极接入输入电信号的一 位数据， 其中， 自光信号输出端起的第 m个电极接入自输入电信号最低位 起的第 m位数据， 其中， m为大于 0且小于或等于电极个数的正整数。
本发明实施例第二方面提供一种电光调制器， 所述电光调制器包括： 第一光信号调制通路， 所述第一光信号调制通路为本发明实施例第一 方面至第一方面第五种可能的实现方式任意一项所述光信号调制通路， 第 一光信号调制通路两端分别与光信号输入端口以及光信号输出端口相连， 第一光信号调制通路中的每个电极分别接入输入电信号的一位数据； 光信号输入端口， 用于接收调制前的光信号；
光信号输出端口， 用于输出利用输入电信号调制后的光信号。
本发明实施例第二方面的第一种可能的实现方式中， 所述电光调制器 还包括：
第二光信号调制通路， 所述第二光信号调制通路为本发明实施例第一 方面至第一方面第五种可能的实现方式任意一项所述的光信号调制通路， 第二光信号调制通路两端分别与光信号输入端口以及光信号输出端口相 连， 第二光信号调制通路中的每个电极分别接入输入电信号的一位数据； 所述第一光信号调制通路上的各个电极与第二光信号调制通路的各个 电极的外加电场方向相反。
结合本发明实施例第二方面的第一种可能的实现方式， 在第二种可能 的实现方式中， 所述电光调制器还包括：
两个直流电极， 所述两个直流电极分别设置在第一光信号调制通路以 及第二光信号调制通路的光信号输入端口， 用于调节调制器的工作电压， 从而调节调制器的调制格式。
本发明实施例第三方面提供一种光发射机， 应用于相干光通信系统的 发射端。 所述光发射机包括：
编码器， 多个放大器通路以及一个本发明第二方面至第二方面第二种 可能的实现方式任意一项所述的电光调制器；
所述编码器将输入数据编码后转换成输入电信号输出至多个放大器通 路；
所述放大器通路的个数与所述电光调制器中信号调制通路上的电极的 个数相等， 每个所述放大器通路用于将输入电信号的一位数据放大后输出 至所述电光调制器中与其相连的一个电极。
本发明第三方面的第一种可能的实现方式中， 所述光发射机还包括： 一个数模转换器， 所述数模转换器将从编码器接收的所述输入电信号 进行数模转换后， 输出至所述多个放大器。
由上述内容可知， 本发明实施例有如下有益效果： 本发明实施例提供了一种光信号调制通路， 电光调制器以及光发射机， 所述光信号调制通路包括： 至少两个电极从光信号输入端口至光信号输出 端口依次相连， 每个电极用于在外部输入电信号为高电平时改变输入光信 号的相位； 所述至少两个电极包括基准电极， 所述基准电极是外部输入高 电平时所改变输入光信号相位最小的电极， 所述基准电极所改变的相位为 基准相位， 其他电极的电极参数与所述基准电极的电极参数不同， 其他电 极在外部输入高电平时所改变的输入光信号的相位大于基准相位， 所述电 极参数包括电极的电光晶体的折射率材料参数和 /或在电场作用方向为横 向时的电场宽度。 光信号调制通路上除基准电极以外的其他电极与基准电 极的电光晶体的材料参数和 /或在电场作用方向为横向时的电场宽度不同， 其他电极所改变的输入光信号的相位大于基准电极所改变的输入光信号的 相位， 在整个光信号调制通路所占空间一定的情况下， 使得光信号调制通 路上的电极都接入高电平时， 与光信号调制通路上只有基准电极相比， 增 大所改变的输入光信号的相位大小， 无需增加电极的个数或者增加单个电 极的长度， 即可实现增大整个光信号调制通路所能改变的输入光信号的相 位的累计大小。 本发明实施例提供的光信号调制通路尺寸小， 便于集成， 灵活度高。 附图说明
为了更清楚地说明本发明实施例或现有技术中的技术方案， 下面将对 实施例或现有技术描述中所需要使用的附图作简单地介绍， 显而易见地， 下面描述中的附图仅仅是本发明的一些实施例， 对于本领域普通技术人员 来讲， 在不付出创造性劳动的前提下， 还可以根据这些附图获得其他的附 图。
图 1 为现有技术中 MZM结构示意图；
图 2 为现有技术中电光调制器的结构示意图；
图 3 ( a ) 为电场作用方向为纵向示意图；
图 3 ( b ) 为电场作用方向为横向示意图；
图 4 本发明一种光信号调制通路实施例一结构示意图； 图 5为本发明一种电光调制器实施例六结构示意图;
图 6为本发明一种电光调制器实施例七结构示意图;
图 7为本发明一种光发射机实施例八结构示意图。 具体实施方式
为了给出在电极所占空间一定的情况下， 增大整个光信号调制通路所 能改变的光信号的相位的累计大小的实现方案， 本发明实施例提供了一种 电光调制器以及电光调制方法， 以下结合说明书附图对本发明的优选实施 例进行说明， 应当理解， 此处所描述的优选实施例仅用于说明和解释本发 明， 并不用于限定本发明。 并且在不冲突的情况下， 本申请中的实施例及 实施例中的特征可以相互组合。
如图 3所示， 电极上所加的电场有两种类型：
第一种类型如图 3 ( a ) 所示， 电极外加电场的方向与电极中光信号的 传播方向平行， 此时电场作用方向为纵向， 釆用公式（ 1 )计算单个电极所 改变的光信号的相位 ^
rN3v ( Λ
φ = π ( 丄入 第二种类型如图 3 ( b ) 所示， 电极外加电场的方向与电极中光信号的 传播方向垂直， 此时电场作用方向为横向， 釆用公式（2 )计算单个电极所 改变的光信号 ^
Figure imgf000008_0001
其中， 为线性电光系数， N为电光晶体的折射率， V为外加电场的电 压， 为输入光信号的波长， Z为电极长度， d为电场宽度。
当然，外加电场的方向可以与电极中光信号的传播方向有大于 0。 且小 于 90。 的夹角， 此时， 外加电场的方向可以分为平行于电极中光信号的传 播方向的分量以及垂直于电极中光信号的传播方向的分量。 相应的光信号 的相位的改变即为平行于电极中光信号的传播方向的电场分量所改变的相 位， 和垂直于电极中光信号的传播方向的电场分量的和。
由于现有技术中是通过改变电极的长度 Z来改变电极对光信号所改变 的相位的大小， 因此， 在现有技术中， 所加的外电场的方向为横向， 由于 当外加电场的方向为纵向时， 改变电极的长度无法改变电极对光信号所改 变的相位的大小。现有技术中只釆用了通过改变电极长度 Z实现对光信号调 制通路对光信号所改变的相位 进行细分量化， 一种方法是， 光信号调制 通路上每个电极的长度相同， 所改变的光信号的相位相同， 累计改变相位 φ , 实现在光信号调制通路上对相位 均分的细分量化； 另一种方式是， 光 信号调制通路上每个电极的长度不同， 所改变的光信号的相位也不同， 累 计改变相位 ^， 实现在光信号调制通路上对相位 不均分的细分量化。 上述 两种方式都仅仅通过改变电极的长度 I实现对相位 φ的细分量化， 当外加电 场的方向为纵向， 或者光信号调制通路所占空间一定时， 不能通过改变长 度 Ζ实现细分量化时， 现有技术中没有给出对相位 的细分量化其他的实现 方式。
由公式 （ 1 ) 和公式 （2 ) 可以看出， 与相位 有关的电极参数除了电 极长度以外， 还有电光晶体的折射率 ， 线性电光系数 外加电场方向为 横向时电场宽度 d以及外加电场的电压 V。 本发明下述实施例主要讨论电极 在电光晶体的材料参数不同， 或者在外加电场方向为横向时电场宽度 ^ /不 同， 再或者材料参数不同以及在外加电场方向为横向时电场宽度 d不同， 还或者材料参数不同、 外加电场作用方向不同以及在外加电场方向为横向 时电场宽度 ί /不同的情况下实现对光信号调制通路上相位 φ的细分量化，以 实现在不增加电极个数或改变电极长度的前提下， 增大整个光信号调制通 路对光信号累计所改变的相位的大小。
下面结合附图对本发明实施例进行详细说明。
实施例一
图 4为本发明一种光信号调制通路实施例一结构示意图， 所述光信号 调制通路应用于电光调制器， 所述光信号调制通路包括：
至少两个电极从光信号输入端口至光信号输出端口依次相连， 每个电 极用于在外部输入电信号为高电平时改变输入光信号的相位。
如图 4所示的光信号调制通路， 左端与光信号输入端口相连， 右端与 光信号输出端口相连， 从光信号调制通路的光信号输出端口至光信号输入 端口， 电极 β。， 电极 ， 电极 β2， ...， 电极 —共 η个电极依次连接组成 光信号调制通路。
所述光信号调制通路中， 电极的个数与输入电信号的位宽相同， 每个 电极接入输入电信号的一位数据， 其中， 自光信号输出端起的第 m个电极 接入自输入电信号最低位起的第 m位数据， 其中， m为大于 0且小于或等 于电极个数的正整数。
在光信号调制通路上依次相连的各个电极， 每个电极接入输入电信号 的一位数据， 从光信号的输出端口至光信号的输入端口， 依次接入输入电 信号的最低位至最高位。 如图 4所示， 电极 β。接入输入信号的最低位， 电 极 接入输入信号的第二位， 电极 β3接入输入信号的第三位， 以此类推， 电极 接入输入信号的第 η位 （最高位）。 每个电极在其所接入的输入电 信号为高电平时， 改变输入光信号的相位。 整个光信号调制通路所改变的 光信号的相位 的大小， 为各个电极利用所接入的电信号所改变的光信号 相位的累加。
所述至少两个电极包括基准电极， 所述基准电极是外部输入高电平时 所改变输入光信号相位最小的电极， 所述基准电极所改变的相位为基准相 位， 其他电极的电极参数与所述基准电极的电极参数不同， 其他电极在外 部输入高电平时所改变的输入光信号的相位大于基准相位， 所述电极参数 包括电极的电光晶体的材料参数和 /或电场作用方向与输入光信号传输方 向垂直时的电场宽度。
其中， 所述材料参数为电极的电光晶体的折射率的立方与电极的电光 晶体的电光系数的乘积。 基准电极在外部输入高电平时所改变的输入光信号相位最小。如图 4所示， 以电极 β。为基准电极为例， 电极 ^所接入的电信号为高电平时， 所改变的 光信号的相位为％。 其他电极： 电极 电极 β2， ...， 电极 β„— ,与电极 ^的 电极参数不同， 并且， 电极 ， 电极 β2， ...， 电极 在所接入的电信号为 高电平时， 所改变的光信号的相位 ,%,· ··^^大于％。
这里需要说明是， 电极 ， 电极 β2， ...， 电极 在所接入的电信号为 高电平时， 所改变的光信号的相位^ ,···^^大于％有多种情况： 第一种情况： 电极 ， 电极 β2， ...， 电极 在所接入的电信号为高电 平时， 所改变的光信号的相位 ,只是大于 ， 但 ，％，···^^之间没 有一定规律的比例关系；
第二种情况： 电极 ， 电极 β2， ...， 电极 在所接入的电信号为高电 平时， 所改变的光信号的相位 , i不仅大于 ， 并且 , , 2,.i„— i之 间的比例关系为 2"- 1： 2"- 2 :···2:1;
第三种情况： 电极 ， 电极 β2， ...， 电极 在所接入的电信号为高电 平时， 所改变的光信号的相位 , 1不仅大于 Ψ。， 并且 , ΐ, 2，··Ίΐ之 间的比例关系为 1： 2 :···2"-2： 2"-1。
这里需要说明的是， 光信号调制通路的电极对输入光信号相位的改变 不仅限于上述三种情况， 还可以位于光信号调制通路中间的电极在所接入 的电信号为高电平时， 所改变的输入光信号的相位最大， 由中间相两边的 电极所接入的电信号为高电平时， 所改变的输入光信号的相位依次减小； 还可以是位于光信号调制通路中间的电极在所接入的电信号为高电平时， 所改变的输入光信号的相位最小， 由中间相两边的电极所接入的电信号为 高电平时， 所改变的输入光信号的相位依次增大。 这里不仅限于上述几种 情况， 只要是光信号调制通路上相同长度的电极中， 其他电极的电极参数 与基准电极的电极参数不同， 并且在所接入的电信号为高电平时， 所改变 的输入光信号的相位大于基准相位即可， 这里不再——赘述。
实际应用时， 为了使用方便， 一般釆用第三种情况， 不在电光调制器 外额外的进行复杂编码即可获得输入电信号与输出光信号所改变相位之间 的特定的映射关系： 当光信号调制通路上的电极在所接入的电信号都为高 电平时， 按照从光信号输出端口至光信号输入端口的顺序所排列的电极对 输入光信号所改变的相位比为： I：2：… 2"— 2 : 2"— 其中， η为电极的个数。
基准电极^所改变的光信号的相位为 ， 电极 所改变的光信号的相 φχ = 2φ0 , 电极 2所改变的光信号的相位％ =4%， ...， 电极 所改变的 光信号的相位
Figure imgf000011_0001
= 2" φ0。 当光信号调制通路上的电极在所接入的电信号都 为高电平时， 即实现对光信号调制通路上相位 的细分量化符合自然编码 规律， φ = φ0 + φι + φ2 -\ h φη_。
光信号调制通路上的各个电极 β。， 电极 βι， 电极 β2， ...， 电极 β„— ,的电 极参数不同， 所述电极参数包括电极的电光晶体的材料参数和 /或电场作用 方向与输入光信号传输方向垂直时的电场宽度， 按照从光信号输出端口至 光信号输入端口的排列顺序， 光信号调制通路上的单个电极对光信号相位 的改变的大小成倍递增， (^ ： ^ ：^ ：…二 ^^。 实现对光信号调制通 路上相位 的细分量化符合自然编码的规律， 此时不需要对输入电信号进 行额外的复杂的编码， 即可得输入电信号与输出光信号相位之间的特定的 映射关系。
其中， 所述材料参数为电极的电光晶体的折射率的立方与电极的电光 晶体的电光系数的乘积。
由上述内容可知， 本发明实施例有如下有益效果：
至少两个电极从光信号输入端口至光信号输出端口依次相连， 每个电 极用于在外部输入电信号为高电平时改变输入光信号的相位； 所述至少两 个电极包括基准电极， 所述基准电极是外部输入高电平时所改变输入光信 号相位最小的电极， 所述基准电极所改变的相位为基准相位， 其他电极的 电极参数与所述基准电极的电极参数不同， 其他电极在外部输入高电平时 所改变的输入光信号的相位大于基准相位， 所述电极参数包括电极的电光 晶体的折射率材料参数和 /或在电场作用方向为横向时的电场宽度。 光信号 调制通路上除基准电极以外的其他电极与基准电极的电光晶体的材料参数 和 /或在电场作用方向为横向时的电场宽度不同， 其他电极所改变的输入光 信号的相位大于基准电极所改变的输入光信号的相位， 在整个光信号调制 通路所占空间一定的情况下， 使得光信号调制通路上的电极都接入高电平 时， 与光信号调制通路上只有基准电极相比， 增大所改变的输入光信号的 相位大小， 无需增加电极的个数或者增加单个电极的长度， 即可实现增大 整个光信号调制通路所能改变的输入光信号的相位的累计大小。 下面结合具体的实例对不同的电极参数实现对光信号调制通路的相位 的细分量化进行详细描述， 下述实例中， 光信号调制通路上按照从光信 号输出端口至光信号输入端口的顺序所排列的电极对输入光信号所改变的 相位比为： I：2：… 2 实施例二至实施例四以由三个电极相连所组成 的光信号调制通路为例， 其他个数的电极相连所组成的光信号调制通路与 之类似， 这里不再——赘述。 实施例二
实施例二中，光信号调制通路上各个电极的电光晶体的材料参数不同， 实现对光信号调制通路所改变的相位 的细分量化：
至少两个电极依次相连， 各个电极的电光晶体的材料参数不同， 按照 从光信号输出端口至光信号输入端口的顺序所排列的电极的电光晶体的材 料参数的比为： Ι ^ ^2 : · ·· ^"-2 ^"-1 , 其中， η为电极的个数。 其中， 所述材 料参数为电极的电光晶体的折射率的立方与电极的电光晶体的电光系数的 乘积。
居公式（ 1 )和公式（ 2 )， 可以看出外加电场为纵向或横向时， 电极 所改变的相位 都与电极的电光晶体的折射率 N以及电极的电光晶体的电 光系数 r有关， 即各个电极的电光晶体的折射率 N以及电光系数 r不同， 各 个电极对光信号的相位所改变的大小不同。 由于相位 与电光晶体的折射 率 N的立方以及电光系数 r 的乘积成正比， 因此， 设置光信号调制通路上 的 各个 电 极 β。,βρβ , 的 电 光 晶 体 的 材料参数 的 比 为 ： r0N0 3： Γ,Ν " r2N2 3 rn_,N n = 1： 2： 22： · · ·： 2η ， 实现各个电极 β。， β β2… β„— i对光 信调制通路上的相位 的细分量化符合自然编码规律。
假设电极 β。的电光晶体的折射率为 N。，对光信号的相位改变大小为 ， 以三个电极相连所组成的光信号调制通路为例，表 1中列出了三个电极 β。、 和 2的折射率， 以及每个电极对光信号所改变的相位的大小。
表 1 电极的折射率不同 电极 材料参数 改变相位的大小
Bo r N 3
φ0 Bi
2 r N 3 2 Po
B2
A r N 3 ½0 由表 1中可以看出， 电极 B。所改变的光信号的相位的大小为 ， 电极 所改变的光信号的相位的大小为 2 ，电极 B2所改变的光信号的相位的大 小为 ½。， 通过设置电极 BQ 、 和 B2不同的电光晶体的折射率， 实现对光 信号调制通路上所改变的相位 进行细分量化符合自然规律， 使电极 B。、 Bi 和 所改变的光信号的相位的大小成倍递增。
电极的个数与输入电信号的位宽相同， 每个电极接入输入电信号的一 位数据， 其中， 自光信号输出端起的第 m个电极接入自输入电信号最低位 起的第 m位数据， 其中， m为大于 0且小于或等于电极个数的正整数。
在光信号调制通路上依次相连的各个电极， 每个电极接入输入电信号 的一位数据， 从光信号的输出端口至光信号的输入端口， 依次接入输入电 信号的最低位至最高位。 如图 4所示， 电极 β。接入输入信号的最低位， 电 极 接入输入信号的第二位， 电极 β3接入输入信号的第三位， 以此类推， 电极 接入输入信号的第 η位 （最高位）。 整个光信号调制通路所改变的 光信号的相位 的大小， 为各个电极利用所接收到的电信号所改变的光信 号相位的累加。
表 2为输入电信号的编码与光信号在输出端相对于输入端所改变的相 位 对照表。 由表 2 中的内容可知， 光信号经过光信号调制通路进行调制 后， 在输出端相对于输入端所改变的相位 符合自然编码规律。 表 2 输入电信号编码与光信号在输出端相对于输入端所改变的相位 输入电信号编码
光信号在输出端相对于输入端所改变的相位
000 0
001
φ0 010
2%
Oil
100
101
110
111 ， φ
这里需要说明是， 改变电极的电光晶体的折射率可以通过对电极的电 光晶体中添加金属杂质或金属化合物实现， 例如： 可以在电光晶体中添加 不同浓度的铁元素或氧化镁等， 实现对电光晶体折射率的改变。
由上述内容可知， 实施例二还有如下有益效果：
实施例二给光信号调制通路上各个电极的电光晶体的折射率 Ν以及电 光系数 r 不同， 则电极对输入光信号的的折射率不同， 因此对光信号所改 变的相位的大小也不同， 在外加电场为纵向时， 也可以实现从光信号输出 端口至光信号输入端口所排列的各个电极对光信号的相位的改变符合自然 编码规律； 同时， 由于电极的电光晶体的材料参数的不同， 从光信号输出 端口至光信号输入端口所排列各个电极对光信号相位的改变成倍增加， 与 现有技术相比， 对光信号改变相同大小的相位所需的电极个数较少， 减小 了光信号调制通路所占的空间， 以及所花费的成本。 实施例三
实施例三中， 光信号调制通路上各个电极的电场作用方向与光信号传 输方向垂直时电场宽度不同， 实现对光信号调制通路所改变的相位 的细 分量化：
至少两个电极依次相连， 各个电极的电场宽度不同， 所述电场作用方 向与光信号传输方向垂直时， 按照从光信号输出端口至光信号输入端口的 顺序所排列的电极的电场作用方向为横向时电场宽度的比为：
1：1:1:... 1 , 其中， n为电极的个数。
2 4 2"- 1
根据公式（2 )可知， 在外加电场为横向 （外加电场方向与光信号传输 方向垂直）时， 电极所改变的相位 与外加电场的电场宽度 d有关， 其他条 件一定时， 电极的电场宽度 d不同， 电极所改变的光信号的相位不同。 由 于相位 与电场宽度 ^ /成反比， 因此， 设置光信号调制通路上各个电极 β。, βρ β2〜β„— i的电场宽度的比为： ^： ：^ :…^^ ^ : ^ :…：^ , 实现各 个电极 β。，β1，β2… - i对光信调制通路上的相位 的细分量化符合自然编码 规律。 这里需要说明的是， 上述外加电场还可以与输入光信号的方向有一 定的夹角， 但是在与光信号传输方向垂直的方向上有分量。
假设电极 β。的电场宽度为 ， 对光信号的相位改变大小为 ， 以三个 电极相连所组成的光信号调制通路为例，表 3中列出了三个电极 β。、 £!和£2 的电场宽度， 以及每个电极对光信号所改变的相位的大小。
表 3 电极的电场宽度不同
Figure imgf000016_0001
由表 3中可以看出， 电极 Β。所改变的光信号的相位的大小为 ， 电极 所改变的光信号的相位的大小为 2%，电极 B2所改变的光信号的相位的大 小为 ½。， 通过设置电极 Β。 、 和 B2不同的电场宽度， 实现对光信号调制 通路上所改变的相位 进行细分量化符合自然规律， 使电极 B。 、 Bi 和 B2所 改变的光信号的相位的大小成倍递增。
电极的个数与输入电信号的位宽相同， 每个电极接入输入电信号的一 位数据， 其中， 自光信号输出端起的第 m个电极接入自输入电信号最低位 起的第 m位数据， 其中， m为大于 0且小于或等于电极个数的正整数。 在光信号调制通路上依次相连的各个电极， 每个电极接入输入电信号 的一位数据， 从光信号的输出端口至光信号的输入端口， 依次接入输入电 信号的最低位至最高位。 如图 4所示， 电极 β。接入输入信号的最低位， 电 极 接入输入信号的第二位， 电极 β3接入输入信号的第三位， 以此类推， 电极 接入输入信号的第 η位 （最高位）。 整个光信号调制通路所改变的 光信号的相位 的大小， 为各个电极利用所接收到的电信号所改变的光信 号相位的累加。
输入电信号的编码与光信号在输出端相对于输入段所改变的相位 与 表 2相同， 参考实施例一中的描述， 光信号经过光信号调制通路进行调制 后， 在输出端相对于输入端所改变的相位 符合自然编码规律。
有上述内容可知， 实施例三有如下有益效果：
在改变光信号的相位时， 只需改变电极的外加电场宽度即可， 操作简 单， 无需改变电极的长度或增加电极的个数， 实现在输出端相对于输入端 所改变的相位 符合自然编码规律。 实施例四
实施例二中， 光信号调制通路上各个电极的电光晶体的材料参数以及 在电场作用方向与光信号传输方向垂直时电场宽度不同， 实现对光信号调 制通路所改变的相位 的细分量化：
至少两个电极依次相连， 各个电极的材料参数和电场宽度不同， 按照 从光信号输出端口至光信号输入端口的顺序所排列的电极的电光晶体的材 料参数的比为：
Figure imgf000017_0001
电场作用方向与输入光信号传输 方向垂直， 按照从光信号输出端口至光信号输入端口的顺序所排列的电极 的电场作用方向为横向时电场宽度的比为： d0 Ά : d2 : ··· — 1； 使 其中， η为电极的个数。
Figure imgf000017_0002
假设电极 β。的电光晶体的折射率为 N。， 电场宽度为 ， 对光信号的相 位改变大小为 ， 以四个电极相连所组成的光信号调制通路为例， 表 4 中 列出了四个电极 β β 2和 的折射率， 电场宽度以及每个电极对光信 号所改变的相位的大小。 表 4 折射率以及电场宽度不同
Figure imgf000018_0001
由表 4中可以看出， 电极 Β。所改变的光信号的相位的大小为％， 电极 所改变的光信号的相位的大小为 2%，电极 B2所改变的光信号的相位的大 小为 ½。， 电极 B3所改变的光信号的相位的大小为 8 ， 通过设置电极 B。 、 Bi 、 B2和 B3不同的电光晶体的折射率以及电场宽度实现对光信号调制通路 上所改变的相位 进行细分量化符合自然规律， 使电极 B。 、 Bi 、 B2和 B3所 改变的光信号的相位的大小成倍递增。
电极的个数与输入电信号的位宽相同， 每个电极接入输入电信号的一 位数据， 其中， 自光信号输出端起的第 m个电极接入自输入电信号最低位 起的第 m位数据， 其中， m为大于 0且小于或等于电极个数的正整数。
在光信号调制通路上依次相连的各个电极， 每个电极接入输入电信号 的一位数据， 从光信号的输出端口至光信号的输入端口， 依次接入输入电 信号的最低位至最高位。 如图 4所示， 电极 β。接入输入信号的最低位， 电 极^接入输入信号的第二位， 电极 β3接入输入信号的第三位， 以此类推， 电极 接入输入信号的第 η位 （最高位）。 整个光信号调制通路所改变的 光信号的相位 的大小， 为各个电极利用所接收到的电信号所改变的光信 号相位的累加。
表 5为输入电信号的编码与光信号在输出端相对于输入端所改变的相 位 对照表。 由表 5 中的内容可知， 光信号经过光信号调制通路进行调制 后， 在输出端相对于输入端所改变的相位 符合自然编码规律。 表 5 输入电信号编码与光信号在输出端相对于输入端所改变的相位 输入电信号编码
光信号在输出端相对于输入端所改变的相位
0000 0
0001
φ0
0010
0011
0100
0101
0110
6 %
0111
7
1000
8 %
1001
1010
1011
l l ^o 1100
12
1101
1110
1111
15
实施例四中， 釆用折射率以及电场宽度两个参数共同改变电极对光信 宽度的具体设置方式， 还可以釆用其他的折射率与电场宽度两个参数的组 合设置方式， 只要保证^ : ^ : ^ : · · · : ^ι^ = 1 : 2 : 4：…：2«- 1， 用以实现 在输出端相对于输入端所改变的相位 符合自然编码规律即可。
釆用折射率与电场宽度两个参数共同控制电极所改变的光信号的相 位， 有如下优点：
对于仅仅改变电极的折射率来说， 改变每一个电极的电光晶体的材料 参数操作比较复杂， 并且需要对不同的电极掺杂不同浓度的金属或者金属 混合物， 操作复杂； 对于只改变电极的电场宽度来说， 电场宽度成倍减小， 电场宽度很难减小到初始电场宽度的 1/4， 甚至更小。 釆用电光晶体的材料 参数以及电场宽度两个参数总和改变电极对光信号相位所改变的大小， 可 以简化对电极折射率以及电场宽度改变操作的复杂度。
在实施例四中， 四个电极， 只改变两个电极的折射率， 并且两个电极 的折射率改变一致； 只需要将两个电极的电场宽度减小初始电场宽度 d0的 二分之一，无需改变为初始电场宽度 d。的 1/4和 1/8，减小了实现的复杂度。 实施例五
所述电极参数包括电场作用方向， 电极的电极长度与电场宽度的比、 电光晶体的材料参数不同， 实现对光信号调制通路所改变的相位 的细分 量化：
当电场作用方向为纵向 （电场作用方向与光信号传输方向平行） 时， 电极对光信号相位的改变与电极长度以及电场宽度无关。
至少两个电极依次相连，各个电极的电极的电极长度与电场宽度的比、 电场作用方向以及电光晶体的材料参数不同， 以使得各个电极所改变的所 述光信号的相位按照从光信号输出端口至光信号输入端口的顺序符合自然 编码的规律。
以四个电极相连所组成的光信号调制通路为例， 表 6 中列出了四个电 极 β。、 β 2和 3的电场作用方向， 折射率， 电极长度与电场宽度的比， 以及每个电极对光信号所改变的相位的大小。 表 6电极的电极长度与电场宽度的比、 电场作用方向以及折射率不同
Figure imgf000021_0001
由表 6可以看出， 电极 β。和电极^的折射率， 电极长度与电场宽度的 比值两个参数虽然相同， 由于电极 β。的电场作用方向是纵向， 电极所改变 的光信号的相位与电极长度和电场宽度无关， 因此， 电极 β。所改变的光信 号的相位为 ，而不是 2 。 当电场作用方向为纵向时， 电极所改变的光信号 的相位与电极长度和电场宽度有关， 如表 6中， 电极 和电极 Β2， 电极 Β2 中， 电极长度与电场宽度的比为电极 ^中比值的二倍， 则电极 Β2所改变的 光信号的相位的大小为电极 所改变光信号大小的二倍。
通过在电场作用方向不同时设置电极 、 Bi 、 82和 B3不同的电光晶体 的材料参数以及电场宽度实现对光信号调制通路上所改变的相位 进行细 分量化符合自然规律， 使电极 BQ 、 Bi 、 B2和 B3所改变的光信号的相位的大 小成倍递增。
光信号调制通路上， 电极的个数与输入电信号的位数相同， 每个电极 接入输入电信号的一位数据， 其中， 自光信号输出端起的第 m个电极接入 自输入电信号最低位起的第 m位数据， 其中， m为大于 0且小于或等于电 极个数的正整数。
在光信号调制通路上依次相连的各个电极， 每个电极接入输入电信号 的一位数据， 从光信号的输出端口至光信号的输入端口， 依次接入输入电 信号的最低位至最高位。 如图 4所示， 电极 β。接入输入信号的最低位， 电 极^接入输入信号的第二位， 电极 β3接入输入信号的第三位， 以此类推， 电极 接入输入信号的第 η位 （最高位）。 整个光信号调制通路所改变的 光信号的相位 的大小， 为各个电极利用所接收到的电信号所改变的光信 号相位的累加。
输入电信号的编码与光信号在输出端相对于输入段所改变的相位 与 表 5相同， 参考实施例四中的描述， 光信号经过光信号调制通路进行调制 后， 在输出端相对于输入端所改变的相位 符合自然编码规律。
实施例五还有如下有益效果：
电极参数还包括电场的作用方向， 可以灵活的设置电极的各个参数， 实现光信号调制通路上各个电极， 在输出端相对于输入端所改变的相位 符合自然编码规律。 实施例六
图 5为本发明一种电光调制器实施例六结构示意图， 所述电光调制器 包括：
第一光信号调制通路 501， 所述第一光信号调制通路 501 为本发明实 施例一至实施例五任意一个实施例所述的光信号调制通路， 第一光信号调 制通路两端分别与光信号输入端口以及光信号输出端口相连， 第一光信号 调制通路中的每个电极分别接入输入电信号的一位数据。
光信号输入端口 502， 用于接收调制前的光信号。
光信号输出端口 503， 用于输出利用输入电信号调制后的光信号。 实施例六中， 光电调制器只有一条光信号调制通路， 光信号从电光调 制器的输入端口传输至第一光信号调制通路， 第一光信号调制通路利用输 入电信号对光信号进行调制后从电光调制器的光信号输出端口输出。 实施例七
图 6为本发明一种电光调制器实施例七结构示意图， 所述电光调制器 包括：
第一光信号调制通路 501， 所述第一光信号调制通路为本发明实施例 一至实施例五任意一个实施例所述光信号调制通， 第一光信号调制通路两 端分别与光信号输入端口以及光信号输出端口相连， 第一光信号调制通路 中的每个电极分别接入输入电信号的一位数据路。
第二光信号调制通路 601， 所述第二光信号调制通路为本发明实施例 一至实施例五任意一个实施例所述光信号调制通路， 第二光信号调制通路 两端分别与光信号输入端口以及光信号输出端口相连， 第二光信号调制通 路中的每个电极分别接入输入电信号的一位数据。
光信号输入端口 502， 用于接收调制前的光信号。
光信号输出端口 503， 用于输出利用输入电信号调制后的光信号。 可选的， 所述电光调制器还包括：
两个直流电极 602和 603， 所述两个直流电极分别设置在第一光信号 调制通路以及第二光信号调制通路的光信号输入端口， 用于调节调制器的 工作电压， 从而调节调制器的调制格式。
直流电极 602和 603主要用于分别调节第一光信号调制通路以及第二 光信号调制通路上的工作电压或工作电流的工作点位置， 用来调节电光调 制器的调制格式。
这里需要说明的是， 可以改变第一光信号调制通路或第二光信号调制 通路外加电场电压的正负方向或改变输入电信号的正负来实现第一光信号 调制通路以及第二光信号通路对光信号所改变的相位相反， 实现电光调制 器的推挽作用。 当然， 电光调制器中的第一光信号调制通路以及第二光信 号调制通路中电极对相位 的量化方式可以相同， 也可以不同， 这里不进 行具体限定， 也可以釆用不同的量化方式， 不实现推挽的工作方式。 实施例八
图 7为本发明一种光发射机实施例八结构示意图， 应用与相干光通信 系统的发射端， 所述光发射机包括：
编码器 701，多个放大器通路 F。~F 1和 Do D^以及一个实施例六至实 施例七所述的电光调制器 702。
所述编码器 701将输入数据编码后转换成输入电信号输出至多个放大 器通路；
所述放大器通路的个数与所述电光调制器 701 中一个信号调制通路上 的电极 B。〜： 的个数相等，每个所述放大器通路用于将输入电信号的一位 数据放大后输出至所述电光调制器中与其相连的一个电极。
可选的， 所述光发射机还包括：
一个数模转换器， 所述数模转换器将从编码器接收的所述输入电信号 进行数模转换后， 输出至所述多个放大器 Fo F^以及
Figure imgf000024_0001
显然， 本领域的技术人员可以对本发明进行各种改动和变型而不脱离 本发明的精神和范围。 这样， 倘若本发明的这些修改和变型属于本发明权 利要求及其等同技术的范围之内， 则本发明也意图包含这些改动和变型在 内。

Claims

权 利 要 求
1、 一种光信号调制通路， 其特征在于， 应用于电光调制器， 所述光信 号调制通路包括：
至少两个电极从光信号输入端口至光信号输出端口依次相连， 每个电 极用于在外部输入电信号为高电平时改变输入光信号的相位；
所述至少两个电极包括基准电极， 所述基准电极是外部输入高电平时 所改变输入光信号相位最小的电极， 所述基准电极所改变的相位为基准相 位， 其他电极的电极参数与所述基准电极的电极参数不同， 其他电极在外 部输入高电平时所改变的输入光信号的相位大于基准相位， 所述电极参数 包括电极的电光晶体的材料参数和 /或电场作用方向与输入光信号传输方 向垂直时的电场宽度；
其中， 所述材料参数为电极的电光晶体的折射率的立方与电极的电光 晶体的电光系数的乘积。
2、 根据权利要求 1所述的光信号调制通路， 其特征在于：
所有电极所接入的外部电信号都为高电平时， 按照从光信号输出端口 至光信号输入端口的顺序所排列的电极对输入光信号所改变的相位比为： 1:2:···2"- 2 :2"- 其中， η为电极的个数。
3、 根据权利要求 2所述的光信号调制通路， 其特征在于：
按照从光信号输出端口至光信号输入端口的顺序所排列的电极的电光 晶体的材料参数的比为： Ι^^2:···^"-2^"-1, 其中， η为电极的个数。
4、 根据权利要求 2所述的光信号调制通路， 其特征在于：
所述电场作用方向与输入光信号传输方向垂直， 按照从光信号输出端 口至光信号输入端口 的顺序所排列的电极的电场宽度的比为： 1:-:-:···^-, 其中， η为电极的个数。
5、 根据权利要求 1所述的光信号调制通路， 其特征在于括： 电 场 作 用 方 向 与 输 入 光 信 号 传 输 方 向 垂 直 ，
^:^:^:•••:^^ = 1:2:4:…： 2"， 其中， r。:r1 :r2 :…^分别表示电极 的电光晶体的电光系数， do '.d ^ :-dn_,分别表示电极的电场宽度， N。： N1 :N2 :. N„— i分别表示电极的电光晶体的折射率， n为电极的个数。
6、 根据权利要求 2-5任意一项所述的光信号调制通路， 其特征在于： 电极的个数与输入电信号的位宽相同， 每个电极接入输入电信号的一 位数据， 其中， 自光信号输出端起的第 m个电极接入自输入电信号最低位 起的第 m位数据， 其中， m为大于 0且小于或等于电极个数的正整数。
7、 一种电光调制器， 其特征在于， 所述电光调制器包括：
第一光信号调制通路， 所述第一光信号调制通路为权利要求 1-7任意 一项所述光信号调制通路， 第一光信号调制通路两端分别与光信号输入端 口以及光信号输出端口相连， 第一光信号调制通路中的每个电极分别接入 输入电信号的一位数据；
光信号输入端口， 用于接收调制前的光信号；
光信号输出端口， 用于输出利用输入电信号调制后的光信号。
8、 根据权利要求 7所述的电光调制器， 其特征在于， 所述电光调制器 还包括：
第二光信号调制通路， 所述第二光信号调制通路为权利要求 1-7任意 一项所述的光信号调制通路， 第二光信号调制通路两端分别与光信号输入 端口以及光信号输出端口相连， 第二光信号调制通路中的每个电极分别接 入输入电信号的一位数据；
所述第一光信号调制通路上的各个电极与第二光信号调制通路的各个 电极的外加电场方向相反。
9、 根据权利要求 8所述的电光调制器， 其特征在于， 所述电光调制器 还包括：
两个直流电极， 所述两个直流电极分别设置在第一光信号调制通路以 及第二光信号调制通路的光信号输入端口， 用于调节调制器的工作电压， 从而调节调制器的调制格式。
10、 一种光发射机， 其特征在于， 应用于相干光通信系统的发射端。 所述光发射机包括：
编码器， 多个放大器通路以及一个权利要求 7-9任意一项所述的电光 调制器；
所述编码器将输入数据编码后转换成输入电信号输出至多个放大器通 路；
所述放大器通路的个数与所述电光调制器中信号调制通路上的电极的 个数相等， 每个所述放大器通路用于将输入电信号的一位数据放大后输出 至所述电光调制器中与其相连的一个电极。
11、 根据权利要求 10所述的光发射机， 其特征在于， 所述光发射机还 包括：
一个数模转换器， 所述数模转换器将从编码器接收的所述输入电信号 进行数模转换后， 输出至所述多个放大器。
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