Tunable QPSK (Quadrature Phase Shift Keying) transceiving device based on silicon-based optoelectronic chip

Abstract

The invention relates to a tunable QPSK transceiver based on a silicon-based optoelectronic chip. The tunable QPSK transceiver comprises a first light source module, a second light source module, a first end face coupler, a second end face coupler, an IQ modulation module, a third end face coupler, a frequency shift module, an adjustable optical attenuator module, a fourth end face coupler, an IQ demodulation module and an optoelectronic control module. A coupler, a beam splitter, a beam combiner, a 90-degree optical mixer, a modulator and a detector are integrated on a silicon optical chip, the silicon optical chip, a laser, an optoelectronics control module and the like are packaged together by utilizing a photoelectric hybrid packaging technology, high-density integration is realized, analog phase locking is realized by applying a tunable electro-optical frequency shift technology on a system level, and the system is high in reliability and high in reliability. And the receiving sensitivity reaches a theoretical limit. According to the invention, the design is simple, and compared with other schemes, high-speed and high-capacity short-distance optical interconnection can be realized, meanwhile, the power consumption, the cost and the hardware requirements are reduced, and the miniaturization of devices is realized.

Description

Technical Field

[0001] The present invention relates to on-chip coherent optical communication, and particularly to a tunable QPSK transceiver device based on a silicon-based optoelectronic chip. Background Art

[0002] With the progress of satellite sensing technology, the resolution of its sensors has reached the order of 0.1 m, and the data collected has increased sharply. Limited by the volume, power consumption, and mass of the satellite platform, traditional microwave communication can no longer meet the communication rate requirements of such satellites. Laser communication uses laser as the carrier of information transmission and free space as the transmission channel, with characteristics such as large communication capacity, small divergence angle, and high confidentiality. It is an important technology for the space-ground integrated information network, which can effectively solve the bottleneck problem of satellite communication rate and is of great significance for both people's livelihood and national defense.

[0003] For a traditional space laser coherent communication system constructed based on discrete optoelectronic devices, the integration level of the laser communication payload is low, the power consumption is large, and miniaturization is difficult, which limits its application in space laser communication of satellite Internet. Moreover, the delay of the traditional discrete optical system is relatively high, which results in a low locking bandwidth of the optical phase-locked loop for coherent laser communication and is prone to unlocking, and cannot meet the integration and high-speed requirements of future space laser communication terminals. In addition, existing phase-locking schemes are all digital phase-locking schemes, which have high performance requirements for hardware and algorithms and insufficient reliability, and have certain limitations in the application scenarios of satellite laser communication. Summary of the Invention

[0004] In order to solve the problems of miniaturization, low power consumption, low hardware requirements, and high reliability of the space laser communication system, the present invention proposes a tunable QPSK transceiver device based on a silicon-based optoelectronic chip.

[0005] The technical solution of the present invention is as follows:

[0006] A tunable QPSK transceiver device based on a silicon-based optoelectronic chip includes a first light source module and a second light source module. Its characteristics are that it further includes an optoelectronic control module and on-chip first end-face coupler, IQ modulation module, third end-face coupler, second end-face coupler, frequency shift module, tunable optical attenuator module, IQ demodulation module, and fourth end-face coupler;

[0007] The narrow linewidth signal light output by the first light source module is modulated by the first end-face coupler and the IQ modulation module, and then coupled with external devices through the third end-face coupler module;

[0008] After the narrow-linewidth intrinsic light output by the second light source module is frequency-shifted by the second end-face coupler and the frequency-shifting module, it passes through the variable optical attenuator module and maintains a zero frequency difference with the modulation signal received through the fourth end-face coupler. After zero-difference reception, the intrinsic light and the modulation signal are input into the IQ demodulation module for IQ demodulation;

[0009] The optoelectronic control module is electrically connected to the first light source module and the second light source module respectively to control them to generate stable narrow-linewidth lasers;

[0010] The optoelectronic control module is electrically connected to the on-chip IQ modulation module, frequency-shifting module, variable optical attenuation module, and IQ demodulation module respectively to independently control them, realizing the working point control of the IQ modulation module and the frequency-shifting module, the attenuation ability regulation of the variable optical attenuation module, and the differential amplification of the detector signal in the IQ demodulation module.

[0011] The IQ modulation module includes a first beam splitter, a second beam splitter, a first thermal phase shifter, a third beam splitter, a first electro-optic modulator, a second electro-optic modulator, a third electro-optic modulator, a fourth electro-optic modulator, a second thermal phase shifter, a third thermal phase shifter, a first combiner, a second combiner, a combined beam splitter, a monitoring photodetector, and a waveguide.

[0012] The IQ modulation module receives the narrow-linewidth signal light from the first end-face coupler of the silicon-based optoelectronic chip and splits the signal light 1:1 through the first beam splitter. The upper path of light is split 1:1 through the second beam splitter and is respectively connected to two electro-optic modulators and a thermal phase shifter to form the I path. The lower path of the signal passes through the first thermal phase shifter and is split 1:1 by the third beam splitter and is also connected to two electro-optic modulators and a thermal phase shifter to form the Q path. Finally, it is combined by the combined beam splitter to form the P path and is split 95:5 and input into the straight waveguide and the monitoring photodetector respectively. The monitoring photodetector is used to monitor the working state of the IQ modulation module and is electrically connected to the optoelectronic control module to control the three thermal phase shifters with a DC signal to make the IQ modulation module work at the optimal working point. The waveguide and the third end-face coupler module output the modulation signal.

[0013] The structure of the frequency-shifting module is the same as that of the IQ modulation module. Functionally, the frequency-shifting module mainly realizes the adjustable frequency-shifting function. Specifically, it is manifested that the voltage-controlled oscillator of the optoelectronic control module outputs a tunable electrical oscillation signal, and two signals are formed through the integrated 90° electrical bridge and are respectively applied to the I path and the Q path of the frequency-shifting module to realize the frequency-adjustable frequency-shifting.

[0014] The IQ demodulation module consists of a 90° optical mixer and four GeSi photodetectors. The 90° optical mixer can be a 2*4 MMI or assembled by a thermal phase shifter and four 2*2 MMIs. The frequency-shifted eigen-signal and the signal to be demodulated are input into the 90° optical mixer, and four signals with phase differences of 180°, 270°, 90°, and 0° are respectively output and connected to the GeSi detectors. The GeSi detectors are electrically connected to the transimpedance amplifier circuit integrated with the optoelectronic control module, and balanced detection is performed in the circuit.

[0015] The optoelectronic control module includes a laser control module, a balanced amplification module, a frequency shift control module, and an operating point control module. The optoelectronic control module includes a laser control module, a balanced amplification module, a frequency shift control module, and an operating point control module;

[0016] The laser control module controls the power supply of the light source module 1 and the light source module 2 and regulates them to achieve narrow linewidth output;

[0017] The balanced amplification module is used to differentially amplify the detector signals of the IQ demodulation module;

[0018] The frequency shift control module acts on the electro-optic modulators of the I path and the Q path of the frequency shift module respectively to regulate the eigen-light for frequency shift, and realizes the tunable frequency shift of the eigen-light by programming the FPGA program to tune the frequency of the voltage-controlled oscillator;

[0019] The operating point control module is used to extract the signals of the monitoring photodetectors of the IQ modulation module and the frequency shift module, and controls the output voltage of the adjustable voltage source according to this signal to control the thermal phase shifter to regulate the initial states of the I path, Q path, and P path of the IQ modulation module and the frequency shift module, so as to control them at the optimal operating point

[0020] The laser control module includes a thermoelectric cooling module to control the temperature of the silicon-based optoelectronic chip and the light source module to be constant, and a precise current control module to output precise and stable current to control the laser to output stable narrow linewidth laser.

[0021] The balanced amplification module includes a TIA chip for the transimpedance amplifier circuit, and differential amplification is performed on-chip for the two signals with a phase difference of 180° passing through the 90° optical mixer at the electrical chip to achieve balanced detection.

[0022] The frequency shift control module includes a voltage-controlled oscillator, a 90° hybrid coupler, and an FPGA chip. The FPGA chip controls the voltage-controlled oscillator to generate the required high-frequency oscillation signal, and the 90° hybrid coupler splits the high-frequency oscillation signal into two signals with a 90° phase difference, which are respectively applied to the electro-optic modulators on the I-channel and Q-channel of the frequency shift module to realize the regulation of the intrinsic light for frequency shift. The frequency tuning of the voltage-controlled oscillator is achieved by programming the FPGA to realize the tunable frequency shift of the intrinsic light.

[0023] The operating point control module includes an FPGA chip and a tunable voltage source. By programming the FPGA, the signals of the monitoring photodetectors of the IQ modulation module and the frequency shift module are extracted, and the output voltage of the tunable voltage source is controlled according to these signals to control the thermal phase shifter to regulate the initial states of the I-channel, Q-channel, and P-channel of the IQ modulation module and the frequency shift module, so as to control them at the optimal operating point.

[0024] In the aspect of QPSK modulation, the present invention adopts an electro-optic modulator with a carrier depletion structure, that is, a reverse-biased PN junction, with lower-concentration n-type and p-type dopings distributed in the silicon-based optical waveguide region to form the PN junction; higher-concentration n-type and p-type dopings are distributed in the outer ridge structure of the silicon-based optical waveguide to achieve ohmic contact. The phase modulation is realized by changing the modulation voltage and the DC bias voltage of the electro-optic modulator. The change of its optical field is shown as follows:

[0025]

[0026] where E out represents the output optical field, E in represents the input optical field, and when the DC bias voltage is controlled at the Quad- or Quad+ point and the peak-to-peak value of the modulation signal is V π , OOK modulation can be performed; when the DC bias voltage is controlled at the Min point and the peak-to-peak value of the modulation signal is 2V π , binary phase shift keying BPSK modulation can be performed. When the I-channel and Q-channel MZ modulators are at the Min point and the PM phase shift is 90°, QPSK signal modulation can be performed. The optical fields of the corresponding I-channel, Q-channel, and the combined P-channel are shown as follows:

[0027]

[0028]

[0029]

[0030] In the aspect of QPSK demodulation, mainly, the received signal light and the intrinsic light pass through a 90° optical mixer to output four signals: I+, I-, Q+, and Q-.

[0031] The expressions of the signal light and the local light are denoted as:

[0032]

[0033]

[0034] The expressions of the four signals output after passing through the mixer are:

[0035]

[0036] Where I+ and I- are E1 and E2 respectively, and Q+ and Q- are E3 and E4 respectively.

[0037] After passing through two balanced detectors, photocurrents can be obtained:

[0038]

[0039]

[0040] Where R is the detector responsivity. The two signals are 90 degrees out of phase, so they are called the in-phase terminal and the quadrature terminal.

[0041] Where R is the detector responsivity. The two signals are 90 degrees out of phase, so they are called the in-phase terminal and the quadrature terminal.

[0042] In the homodyne demodulation method implemented by the tunable on-chip frequency shift in the present invention, the signal light and the local light are in the same frequency and in-phase state, that is, (ω S -ω LO )t = 0. At this time, the outputs of the four signals I+, I-, Q+, and Q- after passing through the balanced detector are the baseband signals.

[0043] The advantages of the present invention are:

[0044] Different from directly modulating a laser, the present invention has a simple process, low requirements for the performance of the laser and polymer materials, and excellent radiation resistance and anti-environmental interference.

[0045] The present invention has strong scalability, can implement BPSK, QPSK, and OOK modulations, has the ability to be compatible with multiple modulation formats, and has a high tolerance to optical signal power changes and nonlinear effects.

[0046] The present invention has tunable frequency shift ability. By adopting the form of analog phase-locked loop, it can complete the compensation of Doppler frequency shift caused by the relative motion between satellites within the ns level, realize homodyne QPSK coherent reception, and achieve the reception sensitivity at the theoretical limit. Compared with adjusting the temperature and current of the laser, it can lock faster and achieve a larger loop bandwidth. Compared with the form of digital phase-locked loop that requires a high-speed AD acquisition card and corresponding algorithms, the present invention has very low requirements in this regard.

[0047] The present invention is based on silicon-based optoelectronic technology and integrates CMOS active optoelectronic devices, effectively reducing the space, power consumption and cost of the system, and greatly improving the system stability and anti-interference ability. Brief Description of the Drawings

[0048] Figure 1 It is the overall structure diagram of a tunable QPSK transceiver device based on a silicon-based optoelectronic chip of the present invention

[0049] Figure 2 It is the schematic structural diagram of the IQ modulation module of a tunable QPSK transceiver device based on a silicon-based optoelectronic chip of the present invention

[0050] Figure 3 It is the schematic structural diagram of the frequency shift module of a tunable QPSK transceiver device based on a silicon-based optoelectronic chip of the present invention

[0051] Figure 4 It is the schematic structural diagram of the coherent demodulation module of a tunable QPSK transceiver device based on a silicon-based optoelectronic chip of the present invention

[0052] Figure 5 It is the schematic structural diagram of the optoelectronic control module of a tunable QPSK transceiver device based on a silicon-based optoelectronic chip of the present invention Detailed Embodiments

[0053] The present invention will be further described below in conjunction with examples and drawings, but the protection scope of the present invention should not be limited thereby.

[0054] Figure 1 It is the overall structure diagram of a tunable QPSK transceiver device based on a silicon-based optoelectronic chip of the present invention, including a first light source module 1, a second light source module 2, a first end-face coupler 3, a second end-face coupler 4, an IQ modulation module 5, a third end-face coupler 7, a frequency shift module 6, an adjustable optical attenuator module 8, a fourth end-face coupler 9, an IQ demodulation module 10, and an optoelectronic control module 11.

[0055] The narrow-linewidth signal light output by the first light source module 1 is modulated by the first end-face coupler 3 and the IQ modulation module 5, and then coupled with external devices through the third end-face coupler module 7;

[0056] After the narrow-linewidth intrinsic light output by the second light source module 2 is frequency-shifted by the second end-face coupler 4 and the frequency-shifting module 6, it maintains a zero frequency difference with the modulation signal received through the fourth end-face coupler 9 via the tunable optical attenuator module 8. After zero-difference reception, the intrinsic light and the modulation signal are input into the IQ demodulation module 10 for IQ demodulation;

[0057] The optoelectronic control module 11 is electrically connected to the first light source module 1 and the second light source module 2 respectively to control them to generate stable narrow-linewidth lasers;

[0058] The optoelectronic control module 11 is electrically connected to the on-chip IQ modulation module 5, frequency-shifting module 6, tunable optical attenuation module 8, and IQ demodulation module 10 respectively, and independently controls them to realize the working point control of the IQ modulation module 10 and the frequency-shifting module 6, the attenuation ability regulation of the tunable optical attenuation module 8, and the differential amplification of the detector signal in the IQ demodulation module 10.

[0059] Figure 2 It is a schematic structural diagram of the IQ modulation module of a tunable QPSK transceiver device based on a silicon-based optoelectronic chip according to the present invention, including a first beam splitter 5-1, a second beam splitter 5-2, a first thermal phase shifter 5-3, a third beam splitter 5-4, a first electro-optic modulator 5-5, a second electro-optic modulator 5-6, a third electro-optic modulator 5-7, a fourth electro-optic modulator 5-8, a second thermal phase shifter 5-9, a third thermal phase shifter 5-10, a first combiner 5-11, a second combiner 5-12, a combined beam splitter 5-13, a monitoring photodetector 5-14, and a waveguide 5-15;

[0060] The IQ modulation module 5 receives the narrow-linewidth signal light of the first end-face coupler 3 and is split 1:1 by the first beam splitter 5-1. Among them, the upper path of light is split 1:1 by the second beam splitter 5-2 and is respectively connected to two electro-optic modulators and thermal phase shifters to form the I path. The lower path of the signal passes through the first thermal phase shifter 5-3 and is then split 1:1 by the third beam splitter 5-4 and is also connected to two electro-optic modulators and thermal phase shifters to form the Q path. Finally, it is combined by the combined beam splitter 5-13 to form the P path and is split 95:5 and input into the straight waveguide 5-15 and the monitoring photodetector 5-14 respectively. The waveguide 5-15 is connected to the third end-face coupler module 7 to output the modulation signal; the monitoring photodetector 5-14 monitors the received signal light and is electrically connected to the optoelectronic control module 11, and the three thermal phase shifters are electrically connected to the optoelectronic control module 11 respectively.

[0061] Figure 3It is a schematic structural diagram of the frequency shift module of a tunable QPSK transceiver device based on a silicon-based optoelectronic chip according to the present invention. Its structural composition is the same as that of the IQ modulation module. Its characteristic lies in that, functionally, the frequency shift module 6 mainly realizes the tunable frequency shift function. Specifically, it is manifested that the voltage-controlled oscillator of the optoelectronic control module 11 outputs a tunable electrical oscillation signal, and two signals are formed through the integrated 90° electrical bridge and are respectively applied to the I path and Q path of the frequency shift module 6 to realize the frequency shift with adjustable frequency, and the program is written by FPGA to keep the local light and the received signal light at zero difference to realize zero-difference demodulation and improve the sensitivity of the system to the theoretical limit.

[0062] Figure 4 It is a schematic structural diagram of the coherent demodulation module of a tunable QPSK transceiver device based on a silicon-based optoelectronic chip according to the present invention. Its characteristics are as follows: The IQ demodulation module is composed of a 90° optical mixer 10-1 and four GeSi photodetectors. The 90° optical mixer can be a 2*4 MMI or can be composed of a thermal phase shifter and four 2*2 MMIs pieced together. The frequency-shifted local signal and the signal to be demodulated are input into the 90° optical mixer, and four signals with phase differences of 180°, 270°, 90°, and 0° are respectively output and connected to the GeSi detectors. The GeSi detectors are electrically connected to the transimpedance amplifier circuit integrated in the optoelectronic control module 11, and balanced detection is performed in the circuit.

[0063] Figure 5 It is a schematic structural diagram of the optoelectronic control module of a tunable QPSK transceiver device based on a silicon-based optoelectronic chip according to the present invention, including a laser control module 11-1, a balanced amplification module 11-2, a frequency shift control module 11-3, and an operating point control module 11-4.

[0064] Its characteristics are as follows: The laser control module 11-1 includes a thermoelectric cooling module to control the temperature of the silicon-based optoelectronic chip and the light source module to be constant, and a precise current control module to output a precise and stable current to control the laser to output a stable narrow-linewidth laser.

[0065] The balanced amplification module 11-2 includes a TIA chip for the transimpedance amplifier circuit, and the two signals with a phase difference of 180° passing through the 90° optical mixer are differentially processed on the chip at the electrical chip to realize balanced detection.

[0066] The frequency shift control module 11-3 includes a voltage-controlled oscillator, a 90° hybrid coupler, and an FPGA chip. The FPGA chip controls the voltage-controlled oscillator to generate the required high-frequency oscillation signal, and the 90° hybrid coupler splits the high-frequency oscillation signal into two signals with a 90° phase difference, which are respectively applied to the electro-optic modulators on the I-channel and Q-channel of the frequency shift module 6 to achieve the regulation of the intrinsic light for frequency shift. The frequency tuning of the voltage-controlled oscillator is realized by programming the FPGA to achieve the tunable frequency shift of the intrinsic light.

[0067] The operating point control module 11-4 includes an FPGA chip and a tunable voltage source. The signals of the monitoring photodetectors of the IQ modulation module 5 and the frequency shift module 6 are extracted by programming the FPGA, and the output voltage of the tunable voltage source is controlled according to the signals to control the thermal phase shifter to regulate the initial states of the I-channel, Q-channel, and P-channel of the IQ modulation module 5 and the frequency shift module 6 to control them at the optimal operating point.

Claims

1. A tunable QPSK transceiver device based on a silicon-based optoelectronic chip, comprising a first light source module (1) and a second light source module (2), characterized in that, It further includes an optoelectronic control module (11), as well as a first end-face coupler (3), an IQ modulation module (5), a third end-face coupler (7), a second end-face coupler (4), a frequency shift module (6), an adjustable optical attenuator module (8), an IQ demodulation module (10), and a fourth end-face coupler (9) on the chip; The narrow linewidth signal light output by the first light source module (1) is modulated by the first end-face coupler (3) and the IQ modulation module (5), and then coupled to an external device through the third end-face coupler module (7); The narrow linewidth intrinsic light output by the second light source module (2) is frequency-shifted by the second end-face coupler (4) and the frequency shift module (6), and then passes through the adjustable optical attenuator module (8) to maintain a zero frequency difference with the modulation signal received through the fourth end-face coupler (9). After homodyne reception, the intrinsic light and the modulation signal are input into the IQ demodulation module (10) for IQ demodulation; The optoelectronic control module (11) is electrically connected to the first light source module (1) and the second light source module (2) respectively to control them to generate stable narrow linewidth lasers; The optoelectronic control module (11) is electrically connected to the on-chip IQ modulation module (5), frequency shift module (6), adjustable optical attenuation module (8), and IQ demodulation module (10) respectively to independently control them, realizing the working point control of the IQ modulation module (10) and the frequency shift module (6), the attenuation ability regulation of the adjustable optical attenuation module (8), and the differential amplification of the detector signal in the IQ demodulation module (10).

2. The tunable QPSK transceiver device based on a silicon-based optoelectronic chip according to claim 1, characterized in that: The IQ modulation module (5) includes a first beam splitter (5-1), a second beam splitter (5-2), a first thermal phase shifter (5-3), a third beam splitter (5-4), a first electro-optic modulator (5-5), a second electro-optic modulator (5-6), a third electro-optic modulator (5-7), a fourth electro-optic modulator (5-8), a second thermal phase shifter (5-9), a third thermal phase shifter (5-10), a first combiner (5-11), a second combiner (5-12), a combined beam splitter (5-13), a monitoring photodetector (5-14), and a waveguide (5-15); The IQ modulation module (5) receives the narrow linewidth signal light from the first end-face coupler (3) and splits it 1:1 through the first beam splitter (5-1). Among them, the upper path of light is split 1:1 through the second beam splitter (5-2) and is respectively connected to two electro-optic modulators and a thermal phase shifter to form the I path. The lower path of the signal passes through the first thermal phase shifter (5-3) and is then split 1:1 by the third beam splitter (5-4) and is also connected to two electro-optic modulators and a thermal phase shifter to form the Q path. Finally, it is combined by the combined beam splitter (5-13) to form the P path and is split 95:5 and input into the straight waveguide (5-15) and the monitoring photodetector (5-14) respectively. The waveguide (5-15) is connected to the third end-face coupler module (7) to output the modulation signal. The monitoring photodetector (5-14) monitors the received signal light and is electrically connected to the optoelectronic control module (11). The three thermal phase shifters are respectively electrically connected to the optoelectronic control module (11).

3. The tunable QPSK transceiver device based on a silicon-based optoelectronic chip according to claim 2, characterized in that: The electro-optic modulator used in the IQ modulation module (5) is a carrier depletion type MZI structure electro-optic modulator.

4. The tunable QPSK transceiver device based on a silicon-based optoelectronic chip according to claim 1, characterized in that, The frequency shift module (6) realizes the adjustable frequency shift function in an analog phase-locked form. Specifically, it is manifested that the voltage-controlled oscillator of the optoelectronic control module (11) outputs an adjustable electrical oscillation signal, and two signals are formed through the integrated 90° electrical bridge and are respectively applied to the I path and the Q path of the frequency shift module (6) to realize the frequency shift with adjustable frequency. And by programming the FPGA, the local light and the received signal light are maintained at zero difference to realize zero-difference demodulation and improve the sensitivity of the system to the theoretical limit.

5. The tunable QPSK transceiver device based on a silicon-based optoelectronic chip according to claim 1, characterized in that: The IQ demodulation module (10) consists of a 90° optical mixer and four GeSi photodetectors. Among them, the 90° optical mixer can be a 2*4 MMI or can be composed of a thermal phase shifter and four 2*2 MMIs pieced together. The frequency-shifted local signal and the signal to be demodulated are input into the 90° optical mixer, and four signals with phase differences of 180°, 270°, 90°, and 0° are respectively output and are connected to the GeSi detectors. The GeSi detectors are electrically connected to the transimpedance amplifier circuit integrated in the optoelectronic control module (11) and perform balanced detection in the circuit.

6. The tunable QPSK transceiver device based on a silicon-based optoelectronic chip according to claim 1, characterized in that: The optoelectronic control module (11) includes a laser control module (11-1), a balanced amplification module (11-2), a frequency shift control module (11-3), and an operating point control module (11-4); The laser control module (11-1) controls the power supply of the light source module (1) and the light source module (2) and regulates it to achieve narrow linewidth output; The balanced amplification module (11-2) is used for differential amplification of the detector signals of the IQ demodulation module; The frequency shift control module (11-3) acts on the electro-optic modulators of the I path and the Q path of the frequency shift module (6) respectively to realize the regulation of the local light for frequency shift, and tunes the frequency of the voltage-controlled oscillator by programming the FPGA to realize the adjustable frequency shift of the local light; The working point control module (11-4) is used to extract the signals of the monitoring photodetectors of the IQ modulation module (5) and the frequency shift module (6), and control the output voltage of the adjustable voltage source according to these signals to control the thermal phase shifter to regulate the initial states of the I-channel, Q-channel, and P-channel of the IQ modulation module (5) and the frequency shift module (6), so as to control them at the optimal working point.

7. The tunable QPSK transceiver device based on a silicon-based optoelectronic chip according to claim 6, characterized in that: The laser control module (11-1) includes a thermoelectric cooling module to keep the temperature of the silicon-based optoelectronic chip and the light source module constant, and a precise current control module to output a precise and stable current to control the laser to output a stable narrow linewidth laser; The balanced amplification module (11-2) includes a TIA chip for the transimpedance amplifier circuit, and differential amplification is performed on-chip for the two signals with a 180° phase difference passing through the 90° optical mixer at the electrical chip to achieve balanced detection; The frequency shift control module (11-3) includes a voltage-controlled oscillator, a 90° electrical bridge, and an FPGA chip. The FPGA chip is used to control the voltage-controlled oscillator to generate the required high-frequency oscillation signal, and the 90° electrical bridge is used to split the high-frequency oscillation signal into two signals with a 90° phase difference; The working point control module (11-4) includes an FPGA chip and an adjustable voltage source. By programming the FPGA, the voltage loaded on the thermal phase shifter by the adjustable voltage source is controlled to achieve working point control.

8. The tunable QPSK transceiver device based on a silicon-based optoelectronic chip according to claim 1, characterized in that: Both the first light source module (1) and the second light source module (2) operate in the communication band.

Images