CN112415829B - Terahertz wave signal generation method and device based on Mach-Zehnder modulator - Google Patents
Terahertz wave signal generation method and device based on Mach-Zehnder modulator Download PDFInfo
- Publication number
- CN112415829B CN112415829B CN202011292849.2A CN202011292849A CN112415829B CN 112415829 B CN112415829 B CN 112415829B CN 202011292849 A CN202011292849 A CN 202011292849A CN 112415829 B CN112415829 B CN 112415829B
- Authority
- CN
- China
- Prior art keywords
- frequency
- signal
- optical
- radio
- comb
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Classifications
-
- 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
- G02F1/21—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 by interference
-
- 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
- G02F1/0102—Constructional details, not otherwise provided for in this subclass
Abstract
The embodiment of the invention provides a terahertz wave signal generation method and device based on a Mach-Zehnder modulator, wherein a radio frequency driving voltage is used for driving the Mach-Zehnder modulator, the radio frequency driving voltage is stable, and the radio frequency driving voltage is equal to half of a half-wave voltage, so that the phase modulation of the Mach-Zehnder modulator is more stable, the frequency of an obtained optical frequency comb is also stable, two optical comb lines selected by a wavelength selection switch are also stable, a vector signal capable of loading pre-coding is loaded on the carrier, a carrier wave of a loading signal is obtained, and the more stable terahertz wave signal is finally generated. This reduces the effect on the mach-zehnder modulator, and ultimately the THz wave generation, using a stable rf drive voltage.
Description
Technical Field
The invention relates to the technical field of optical communication, in particular to a terahertz wave signal generation method and device based on a Mach-Zehnder modulator.
Background
With the rapid development of ultra-high-speed wireless communication services, for example, the fifth Generation mobile communication technology (5th Generation mobile network, abbreviated as 5G) and the sixth Generation mobile communication standard (6th Generation mobile network, abbreviated as 6G) in the future, data is wirelessly transmitted and real-time wireless data is exchanged. In order to obtain a reasonable SIGNAL-to-NOISE RATIO (SNR), THz waves have in fact a certain advantage as information carriers compared to microwave and optical SIGNALs. Radio Frequency (RF) bandwidth is in the microwave and low Frequency millimeter wave bands and naturally enters terahertz (THz). Wherein the frequency of the microwave is 300MHz to 300GHz, the frequency of the low-frequency millimeter wave band is 30-300 GHz, and the frequency range of the THz is 300GHz-10 THz.
In order to obtain the THz signal, the related art uses a phase modulator for processing, and the dc bias voltage of the phase modulator is unstable, so that the influence on the phase modulator is large, and finally, the influence on the generation of the terahertz wave signal is also large.
Disclosure of Invention
An object of an embodiment of the present invention is to provide a terahertz wave signal generation method and apparatus based on a mach-zehnder modulator, which are used to reduce the influence on the mach-zehnder modulator and ultimately reduce the influence on the generation of THz waves by using a stable radio frequency driving voltage. The specific technical scheme is as follows:
in a first aspect, an embodiment of the present invention provides a terahertz wave signal generation method based on a mach-zehnder modulator, including:
the optical frequency comb generating circuit acquires a chirp factor of a Mach-Zehnder modulator; according to a single-frequency light beam generated by a laser, a radio-frequency signal generated by a radio-frequency source and the chirp factor, driving two phase modulators connected in parallel in the Mach-Zehnder modulator through a radio-frequency driving voltage to generate a light-frequency comb, wherein the radio-frequency driving voltage is equal to half of a half-wave voltage, and the Mach-Zehnder modulator is in an intensity modulation mode;
the wavelength selection switch obtains two optical comb lines from the optical frequency comb, wherein one of the two optical comb lines is used as a local oscillator, and the other of the two optical comb lines is used as a carrier;
a second phase modulator obtains vector signals capable of loading precoding, and the vector signals are loaded on the carrier waves to obtain carrier waves loaded with signals;
the first amplifier amplifies the carrier wave of the loading signal to obtain the carrier wave of the amplified loading signal;
the coupler couples the carrier wave of the amplified loading signal with the local oscillator to obtain a coupled signal;
and the single-row carrier photoelectric detector carries out beat frequency on the coupling signal to generate a terahertz wave signal.
Further, the chirp factor is 9;
the frequency interval between the optical frequency combs is 360GHz, and the frequency of a radio frequency signal of a radio frequency source is 30 GHz;
the interval between the two optical comb lines is 360GHz, one of the two optical comb lines is used as a local oscillator, and the other of the two optical comb lines is used as a carrier;
the frequency of the terahertz wave signal is 360 GHz.
Further, the method further comprises: the vector signal capable of loading precoding is obtained by a precoding module through the following steps:
acquiring a pseudo-random binary sequence and a radio frequency carrier;
carrying out 16QAM modulation on the pseudo-random binary sequence to obtain an I path signal and a Q path signal;
respectively carrying out amplitude precoding, phase precoding and quadrature modulation on the I-path signal and the Q-path signal to obtain a precoded 16QAM vector signal, wherein the vector signal comprises: orthogonal I and Q signals;
respectively low-pass filtering the orthogonal I path signal and Q path signal, and loading on the radio frequency carrier to obtain a loaded I path signal and a loaded Q path signal;
and combining the loaded I path signals and the loaded Q path signals to obtain vector signals capable of being loaded with precoding.
Further, after the single-row carrier photodetector beats the coupling signal to generate a terahertz wave signal, the method further includes:
and displaying the terahertz wave signal by an oscilloscope.
Further, after the coupler couples the carrier of the amplified loading signal with the local oscillator to obtain a coupled signal, the method further includes:
the second amplifier amplifies the coupling signal to obtain an amplified coupling signal;
and the single-row carrier photoelectric detector carries out beat frequency on the amplified coupling signal to generate a terahertz wave signal.
Further, the optical frequency comb generating circuit obtains a chirp factor of a mach-zehnder modulator; according to a single-frequency light beam generated by a laser, a radio-frequency signal generated by a radio-frequency source and the chirp factor, two parallel phase modulators in the Mach-Zehnder modulator are driven by a radio-frequency driving voltage to generate an optical frequency comb, and the method comprises the following steps:
a radio frequency signal generated by a radio frequency source;
a single frequency beam generated by a laser;
and one end of each of two parallel phase modulators in the Mach-Zehnder modulator inputs radio frequency driving voltage and direct current bias voltage, the two parallel phase modulators are driven to respectively perform phase modulation on the radio frequency signals to generate an optical frequency comb, and the other end of each of the two parallel phase modulators in the Mach-Zehnder modulator outputs the optical frequency comb.
Further, a chirp factor of a mach-zehnder modulator is obtained in the optical frequency comb generating circuit; according to a single-frequency light beam generated by a laser, a radio-frequency signal generated by a radio-frequency source and the chirp factor, two parallel phase modulators in the Mach-Zehnder modulator are driven by a radio-frequency driving voltage, and after an optical frequency comb is generated, the method further comprises the following steps:
the third amplifier amplifies the frequency of the optical frequency comb, and inputs the amplified signal to the wavelength selective switch as a new optical frequency comb;
the wavelength selective switch obtains two optical comb lines from the optical frequency comb, including:
and the wavelength selection switch obtains two optical frequency combs from the new optical frequency comb, wherein one optical comb line of the two optical frequency combs is used as a local oscillator, and the other optical comb line of the two optical frequency combs is used as a carrier wave.
In a second aspect, an embodiment of the present invention provides a terahertz wave signal generating apparatus based on a mach-zehnder modulator, including:
the optical frequency comb generating circuit is used for acquiring the chirp factor of the Mach-Zehnder modulator; according to a single-frequency light beam generated by a laser, a radio-frequency signal generated by a radio-frequency source and the chirp factor, driving two parallel phase modulators in the Mach-Zehnder modulator through a radio-frequency driving voltage to generate a light-frequency comb, wherein the radio-frequency driving voltage is equal to half of a half-wave voltage, and the Mach-Zehnder modulator is in an intensity modulation mode;
the wavelength selection switch is used for obtaining two optical comb lines from the optical frequency comb, wherein one of the two optical comb lines is used as a local oscillator, and the other of the two optical comb lines is used as a carrier;
a second phase modulator, configured to obtain a vector signal capable of being loaded with precoding, and load the vector signal on the carrier to obtain a carrier loaded with a signal;
the first amplifier is used for amplifying the carrier of the loading signal to obtain the carrier of the loading signal after amplification;
the coupler is used for coupling the carrier wave of the amplified loading signal with the local oscillator to obtain a coupled signal;
and the single-row carrier photoelectric detector is used for carrying out beat frequency on the coupling signal to generate a terahertz wave signal.
Further, the chirp factor is 9;
the frequency interval between the optical frequency combs is 360GHz, and the frequency of a radio frequency signal of a radio frequency source is 30 GHz;
the interval between the two optical comb lines is 360GHz, one of the two optical comb lines is used as a local oscillator, and the other of the two optical comb lines is used as a carrier;
the frequency of the terahertz wave signal is 360 GHz.
Further, the apparatus further comprises: the precoding module is used for obtaining a vector signal capable of loading precoding by adopting the following steps:
acquiring a pseudo-random binary sequence and a radio frequency carrier;
carrying out 16QAM modulation on the pseudo-random binary sequence to obtain an I path signal and a Q path signal;
respectively carrying out amplitude precoding, phase precoding and quadrature modulation on the I path signal and the Q path signal to obtain a precoded 16QAM vector signal, wherein the vector signal comprises: orthogonal I and Q signals;
respectively low-pass filtering the orthogonal I path signal and the orthogonal Q path signal, and loading the signals on the radio frequency carrier to obtain a loaded I path signal and a loaded Q path signal;
and combining the loaded I path signals and the loaded Q path signals to obtain vector signals capable of being loaded with precoding.
The embodiment of the invention has the following beneficial effects:
according to the terahertz wave signal generation method and device based on the Mach-Zehnder modulator, the Mach-Zehnder modulator is driven by the radio-frequency driving voltage, the radio-frequency driving voltage is stable, the radio-frequency driving voltage is equal to half of half-wave voltage, so that phase modulation of the Mach-Zehnder modulator is more stable, the frequency of the obtained optical frequency comb is also stable, two optical comb lines selected by the wavelength selection switch are stable, vector signals capable of loading pre-codes are loaded on the carrier waves, carrier waves of the loaded signals are obtained, and terahertz wave signals are generated finally. This reduces the effect on the mach-zehnder modulator, and ultimately the THz wave generation, using a stable rf drive voltage.
Of course, not all of the advantages described above need to be achieved at the same time in the practice of any one product or method of the invention.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.
Fig. 1 is a schematic flowchart of a terahertz wave signal generation method based on a mach-zehnder modulator according to an embodiment of the present invention;
fig. 2 is a schematic diagram of a first structure of a terahertz wave signal generating apparatus based on a mach-zehnder modulator according to an embodiment of the present invention;
FIG. 3(a) is a schematic optical spectrum through a Mach-Zehnder modulator according to an embodiment of the present invention;
fig. 3(b) is a schematic optical spectrum before entering UTC-PD according to an embodiment of the present invention;
FIG. 4(a) is a spectrum of a laser beam after passing through a laser in a simulation system according to an embodiment of the present invention;
FIG. 4(b) is a diagram of an optical spectrum of an MZM in a simulation system according to an embodiment of the present invention;
fig. 4(c) is an optical spectrum diagram of a simulation result before entering UTC-PD in a simulation system according to an embodiment of the present invention;
FIG. 4(d) is an optical spectrum diagram of a simulation result after entering a UTC-PD in a simulation system according to an embodiment of the present invention;
fig. 5(a) is a second schematic structural diagram of a terahertz wave signal generating apparatus based on a mach-zehnder modulator according to an embodiment of the present invention;
fig. 5(b) is a second schematic structural diagram of the terahertz wave signal generating apparatus based on the mach-zehnder modulator according to the embodiment of the present invention;
FIG. 6 is a schematic diagram of a process of generating a loadable precoded vector signal based on phase precoding according to an embodiment of the present invention;
FIG. 7(a) is a constellation diagram before precoding according to an embodiment of the present invention;
FIG. 7(b) is a constellation diagram with amplitude precoding only according to an embodiment of the present invention;
FIG. 7(c) is a constellation diagram after amplitude precoding and phase precoding according to an embodiment of the present invention;
fig. 8 is a graph showing the relationship between optical power entering the UTC-PD and bit error rate.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be obtained by a person skilled in the art without making any creative effort based on the embodiments in the present invention, belong to the protection scope of the present invention.
For convenience of understanding, the method and the apparatus for generating a terahertz wave signal based on a mach-zehnder modulator according to the embodiments of the present invention will be described in the following.
In order to obtain a reasonable SIGNAL-to-NOISE RATIO (SNR), the bandwidth of Radio Frequency (RF) is in the microwave and low Frequency millimeter wave bands, and naturally enters terahertz (THz). Wherein the frequency of the microwave is 300MHz to 300GHz, the frequency of the low-frequency millimeter wave band is 30-300 GHz, and the frequency range of the THz is 300GHz-10 THz.
In fact, THz waves have certain advantages as information carriers compared to microwaves and optical signals. Compared with the optical link, it has smaller atmospheric disturbance attenuation and is much larger than the available bandwidth of the microwave band. Therefore, the terahertz technology attracts more and more people to research and develop high-speed wireless optical communication systems so as to adapt to wireless services with high bandwidth requirements.
And, recently, photon-assisted millimeter wave and terahertz technologies have greatly increased the channel capacity of wireless communication, even exceeding 100 Gb/s. This is mainly due to the use of efficient spectral modulation, advanced multiplexing techniques and the full use of the available ultra-wideband at high carrier bandwidths. Systems with wireless bit rates in excess of 100Gb/s have been validated at different wireless carrier frequencies. However, in the related art, a phase modulator for generating an optical comb line uses a direct-current bias voltage, and the direct-current bias voltage has a large influence on a radio-frequency signal, and further has a large influence on the phase modulator, and finally has a large influence on generation of a terahertz wave signal; and the dc bias voltage is relatively small, so that the frequency comb generated is also relatively narrow.
In addition, the terahertz based on the Mach-Zehnder modulator provided by the embodiment of the inventionA method and apparatus for generating a Zehnder signal by using a radio frequency driving voltage to drive a Mach-Zehnder modulator, the radio frequency driving voltage being stable, and a DC bias voltage of the Mach-Zehnder modulator being in an orthogonal position, i.e., -V, when the Mach-Zehnder modulator is in intensity modulation π 2, because the DC bias voltage is half of the half-wave voltage, the DC bias voltage has small intensity modulation, and the RF driving voltage is also equal to half of the half-wave voltage, and the range of the RF driving voltage is 0-V π Therefore, the phase modulation of the Mach-Zehnder modulator is more stable, the frequency of the obtained optical frequency comb is more stable, and therefore the two optical comb lines selected by the wavelength selection switch are more stable, the carrier loaded on the carrier is less affected, and the terahertz wave signal is less affected. This reduces the effect on the mach-zehnder modulator, and ultimately the THz wave generation, using a stable rf drive voltage. Meanwhile, the terahertz wave signal generation method based on the Mach-Zehnder modulator can generate different terahertz wave signals according to different radio-frequency driving voltages.
Next, a description is continued on a terahertz wave signal generation method based on a mach-zehnder modulator according to an embodiment of the present invention.
In the process of transmitting the terahertz wave optical signal, information to be loaded needs to be coded at a transmitting end, then an optical frequency comb is used as a carrier, the information to be loaded is loaded on the carrier, then beat frequency is carried out, the terahertz wave signal carrying the information to be loaded is generated, and the terahertz wave signal is transmitted to a receiving end. And the receiving end demodulates and decodes the terahertz wave signal carrying the information to be loaded to obtain the loaded information. This results in the transmitted information.
The terahertz wave signal generation method based on the mach-zehnder modulator provided by the embodiment of the invention is applied to the field of future 6G communication, and specifically applied equipment can be electronic equipment, specifically the electronic equipment can be: intelligent mobile terminal, server, simulation equipment, etc. Without limitation, any electronic device that can implement the embodiments of the present invention is within the scope of the present invention.
As shown in fig. 1 and fig. 2, a terahertz wave signal generation method based on a mach-zehnder modulator according to an embodiment of the present invention may include the following steps:
The Mach-Zehnder modulator adjusts the radio frequency driving voltage and the direct current bias voltage through the chirp factor, and obtains the current frequency line with a higher difference relative to the adjacent frequency lines. The dc bias voltage generally affects the amplitude of the optical frequency combs, while the rf drive voltage is used to generate the frequency of the optical frequency combs and the rf source is used to determine the spacing between adjacent optical frequency combs.
The optical frequency comb generating circuit is short for an optical frequency comb generating circuit. The half-wave voltage is a voltage which is required to be added when the optical path difference between two perpendicular components Ex ', Ey' of the optical wave is half a wavelength when the optical wave propagates in the optical crystal, and is called as a half-wave voltage.
The laser can adopt an external cavity laser, and the optical frequency comb generating circuit comprises: an External Cavity Laser (ECL 1), a Mach Zehnder Modulator (MZM), and a Radio frequency source (fs). Wherein one of the Mach-Zehnder modulators includes: two phase modulators in parallel.
In this way, parameters such as radio frequency driving voltage and direct current bias voltage of the mach-zehnder modulator are adjusted in a VPI (VPI Photonics, which is an analog software) simulation system to adjust the optical frequency comb for optimization. The spectrum of the laser in the simulation system of the embodiment of the invention is shown in fig. 4 (a); the inventionExample the optical spectrum of the MZM in the simulated system is shown in fig. 4(b), the optical spectrum before entering the UTC-PD is shown in fig. 3(a), fig. 3(b) and fig. 4(c), and the optical spectrum after entering the UTC-PD is shown in fig. 4 (d). Wherein n1 and n2 shown in FIG. 3(b) are two selected frequency comb lines, f s For the frequency of the RF source entering the Mach-Zehnder modulator, the value of which determines the spacing between two adjacent frequency comb lines of the optical frequency comb, f c Is the center frequency. At this time, the driving voltage is adjusted to obtain an ideal optical frequency comb. When the chirp factor is 8, as shown in fig. 3(a), the +6 and-6 can be selected as two optical comb lines. Of course, when the chirp factor is 9, +5 and-5 can be selected from the optical spectrum diagram (not shown) of the corresponding mach-zehnder modulator as two optical comb lines; at a chirp of 10, +6 and-6 (not shown) may be selected from the optical spectrum diagram of its mach-zehnder modulator as two optical comb lines. The obtained 360 HZ terahertz wave signal with high relative amplitude has a good relative effect.
After the optical frequency comb is generated in step 110, the generated optical frequency comb is transmitted to the wavelength selection switch, and step 120 is executed as follows.
And step 120, the wavelength selection switch obtains two optical comb lines from the optical frequency comb, wherein one of the two optical comb lines is used as a local oscillator, and the other of the two optical comb lines is used as a carrier.
Wherein, a Wavelength Selective Switch (WSS) selects two optical comb lines, one optical comb line enters PM, and a signal is loaded; the other optical comb line does not load signals and is used as a local oscillator; and the two subsequent optical comb lines are combined together and sent to UTC-PD for beat frequency to generate a terahertz wave signal.
After obtaining the two optical comb lines in step 120, the carrier waves in the two optical comb lines are sent to the second phase modulator, and the local oscillators in the two optical comb lines are sent to a coupler (abbreviated as OC), and the following step 130 is continuously performed.
And step 130, a second phase modulator acquires the vector signal which can be loaded with precoding, and loads the vector signal on the carrier wave to obtain the carrier wave loaded with the signal. The vector signal capable of being loaded with precoding is information to be loaded, and the information is used for completing actual transmission information, such as communication data, in an actual transmission process. This enables transmission of this information to the receiving end via the carrier.
A second Phase modulator (PM for short) as shown in fig. 2, as shown in fig. 5(a) and as shown in fig. 5(b), may process a precoded vector signal, and may be implemented in a software module, that is, a precoding module, where before entering the PM, signal processing is completed, and the optical modulator is used to load a signal on an optical carrier. Specifically, the pre-coding module may be implemented in matlab simulation software, and for clarity of layout, the pre-coding process will be described later.
The modulation of the signal by the second phase modulator PM is used, so that the complexity of the system is effectively reduced, and the cost is reduced.
After the carrier of the loading signal is obtained in the step 130, the carrier of the loading signal is amplified and sent to the coupler, and the following steps 140 and 150 are continuously performed.
The first amplifier, the second amplifier and the like in the embodiment of the invention are all erbium-doped fiber amplifiers.
And 150, coupling the carrier of the amplified loading signal with the local oscillator by the coupler to obtain a coupled signal.
After obtaining the coupled signal in step 150, the coupled signal includes: the method comprises the steps of carrying out local oscillation and loading Carrier waves of signals, and sending coupled signals to a single-row Carrier photoelectric detector UTC-PD (Uni-tracking-Carrier photonic, UTC-PD for short) through a Standard Single Mode Fiber (SSMF);
and 160, performing beat frequency on the coupling signal by the single-row carrier photoelectric detector to generate a terahertz wave signal.
After the step 160, the terahertz wave signal is sent to an oscilloscope, where the terahertz wave signal carries a vector signal capable of being loaded with precoding, so as to enable a receiving end to obtain finally required information.
In an embodiment of the present invention, after the step 160, the method further includes: and displaying the terahertz wave signal by an oscilloscope. The oscilloscope is a real-time oscilloscope (OSC for short). This allows subsequent processing of the signal at the receiving end, such as an oscilloscope.
According to the terahertz wave signal generation method and device based on the Mach-Zehnder modulator, the Mach-Zehnder modulator is driven by the radio-frequency driving voltage, the radio-frequency driving voltage is stable, the radio-frequency driving voltage is equal to half of half-wave voltage, so that phase modulation of the Mach-Zehnder modulator is more stable, the frequency of the obtained optical frequency comb is also stable, two optical comb lines selected by the wavelength selection switch are also stable, vector signals capable of loading pre-codes are loaded on the carrier waves, carrier waves of the loaded signals are obtained, and the more stable terahertz wave signals are generated finally. This reduces the effect on the mach-zehnder modulator, and ultimately the THz wave generation, using a stable rf drive voltage. Meanwhile, the terahertz wave signal generation method based on the Mach-Zehnder modulator can generate different terahertz wave signals according to different radio-frequency driving voltages, and the frequency of the radio-frequency driving voltage is higher than that of the direct-current bias voltage, so that the generated frequency comb is wider.
In a possible implementation manner, a chirp factor may be generally used to determine the rf driving voltage, and in order to set a more appropriate voltage value for the rf driving voltage and obtain a high-frequency terahertz wave signal, an embodiment of the present invention may further include: the chirp factor may be 8 to 10, and an alternative chirp factor is not limited to 9;
the optical frequency comb generating circuit acquires a chirp factor of a Mach-Zehnder modulator; according to a single-frequency light beam generated by a laser, a radio-frequency signal generated by a radio-frequency source and the chirp factor, two parallel phase modulators in the Mach-Zehnder modulator are driven by a radio-frequency driving voltage to generate a light-frequency comb, wherein the radio-frequency driving voltage is equal to half of a half-wave voltage, the frequency interval between the light-frequency combs is 360GHz, the frequency of the radio-frequency signal of the radio-frequency source is 30GHz, and thus the radio-frequency signal of 30GHz is obtained.
The optical frequency comb generating circuit acquires a chirp factor of the Mach-Zehnder modulator; driving two parallel phase modulators in the mach-zehnder modulator by a radio-frequency driving voltage according to a single-frequency beam generated by a laser, a radio-frequency signal generated by a radio-frequency source, and the chirp factor, and generating an optical-frequency comb further comprises:
a radio frequency signal generated by a radio frequency source; a single frequency beam generated by a laser; and one end of each of two parallel phase modulators in the Mach-Zehnder modulator inputs radio frequency driving voltage and direct current bias voltage, the two parallel phase modulators are driven to respectively perform phase modulation on the radio frequency signals to generate an optical frequency comb, and the other end of each of the two parallel phase modulators in the Mach-Zehnder modulator outputs the optical frequency comb. Therefore, the subsequent PM can modulate the vector signal which is precoded in advance, so that the receiving end can receive the normal signal.
The wavelength selection switch obtains two optical comb lines from the optical comb, wherein the interval between the two optical comb lines is 360GHz, one of the two optical comb lines is used as a local oscillator, and the other of the two optical comb lines is used as a carrier;
a second phase modulator acquires vector signals capable of being loaded with precoding and loads the vector signals on the carrier waves to obtain carrier waves for loading the signals;
the loadable precoded vector signal refers to a signal capable of being directly modulated by a phase modulator, for example, the loadable precoded vector signal may be, but is not limited to, a loadable precoded 16 quadrature amplitude modulation QAM vector signal.
The first amplifier amplifies the carrier wave of the loading signal to obtain the carrier wave of the amplified loading signal;
the coupler couples the carrier wave of the amplified loading signal with the local oscillator to obtain a coupled signal;
and the single-row carrier photoelectric detector beats the coupling signal to generate a terahertz wave signal, wherein the frequency of the terahertz wave signal is 360 GHz.
In the above embodiment, the rf driving voltage and the dc bias voltage of the MZM are set by a parameter setting page, such as VPI simulation system, so that the rf driving voltage is equal to the dc bias voltage and both are equal to half the half-wave voltage (V) rf ＝V dc ＝V π And/2), the frequency of an input MZM radio frequency source is 30GHz, the chirp factor of the MZM is set to be 9, so as to adjust the optical frequency comb to be optimized, and a better optical frequency comb is obtained through the MZM. Wherein, V rf Is a radio frequency drive voltage, V dc Is a DC bias voltage, V π For half-wave voltage, rf is short for radio frequency drive, dc is short for direct current drive, and pi represents half-wave and is used for distinguishing from other voltage.
Generally, the frequency of one laser fluctuates, and for two lasers in the related art, the two lasers are independent lasers, and the fluctuations of the two lasers are also independent of each other, so that the fluctuation difference of two optical signals generated by the two lasers respectively may be 2 times of the fluctuation of one optical signal, or more, one optical comb line is selected from each optical signal, and two optical comb lines are selected. And then obtaining a final terahertz wave optical signal based on the two optical comb lines. If the terahertz wave optical signal with 360GHz as the target is used, because the fluctuation difference of two optical signals generated by the two lasers is large, the frequency fluctuation of the two optical comb lines can be selected to be near 360GHz, the obtained final terahertz wave optical signal is obviously deviated from the original target, and the receiving end needs to perform related processing for obtaining the terahertz wave optical signal with 360 GHz.
In the embodiment of the invention, one laser is used, one laser generates optical signal fluctuation, two optical comb lines are selected from the optical comb generated by one optical signal entering the Mach-Zehnder modulator, and the interval between the optical comb lines is 360GHz, which is equivalent to that the two optical comb lines do difference to offset the fluctuation of the optical signal, so that even if the fluctuation exists, the optical comb lines cannot be influenced, the obtained terahertz wave optical signal cannot be influenced, and the problem of frequency shift of the terahertz wave optical signal of 360GHz at the receiving end is also avoided. Compared with two lasers, the problem of frequency deviation in the traditional optical heterodyne beat frequency process is solved, the device cost is reduced, and the complexity of processing received signals by a receiving end is further reduced.
And only one second phase modulator is adopted, and the second phase modulator is limited by the second phase modulator and cannot directly load the 16QAM vector signal, so that the pre-coding module is used for pre-coding the 16QAM vector signal and pre-loading the pre-coded vector signal on a radio frequency carrier, and the vector signal capable of loading the pre-coding is obtained. Compared with the use of a plurality of devices of the IQ phase modulator, the complexity of a hardware circuit is reduced, so that the signal is modulated by the second phase modulator, the complexity of the system is effectively reduced, and the cost is reduced. Moreover, compared with the Q modulator, the cost is higher, and the cost of the embodiment of the invention is lower.
Referring to fig. 5(a), in another possible implementation, the optical frequency comb generating circuit obtains a chirp factor of a mach-zehnder modulator; according to a single-frequency light beam generated by a laser, a radio-frequency signal generated by a radio-frequency source and the chirp factor, driving two phase modulators connected in parallel in the Mach-Zehnder modulator through a radio-frequency driving voltage to generate a light-frequency comb, wherein the radio-frequency driving voltage is equal to half of a half-wave voltage, the frequency interval between the light-frequency combs is 360GHz, and the frequency of the radio-frequency signal of the radio-frequency source is 30 GHz; this results in a radio frequency signal of 30 GHz.
The optical frequency comb generating circuit acquires a chirp factor of the Mach-Zehnder modulator; driving two parallel phase modulators in the mach-zehnder modulator by a radio-frequency driving voltage according to a single-frequency beam generated by a laser, a radio-frequency signal generated by a radio-frequency source, and the chirp factor, and generating an optical-frequency comb further comprises:
a radio frequency signal generated by a radio frequency source; a single frequency beam generated by a laser; and one end of each of two parallel phase modulators in the Mach-Zehnder modulator inputs radio frequency driving voltage and direct current bias voltage, the two parallel phase modulators are driven to respectively perform phase modulation on the radio frequency signals to generate an optical frequency comb, and the other end of each of the two parallel phase modulators in the Mach-Zehnder modulator outputs the optical frequency comb. Therefore, the subsequent PM can modulate the vector signal which is precoded in advance, so that the receiving end can receive the normal signal.
One end of each of the two parallel phase modulators in the mach-zehnder modulator inputs a radio frequency driving voltage and a direct current bias voltage, the two parallel phase modulators are driven to respectively perform phase modulation on the radio frequency signal, the two phase modulation waves are mutually interfered and converted into intensity modulation, an optical frequency comb is generated, and the other end of each of the two parallel phase modulators in the mach-zehnder modulator outputs the optical frequency comb, wherein the direct current bias voltage and the radio frequency signal determine a selection mode of the mach-zehnder modulator, and the selection mode comprises: intensity modulation and push-pull modulation.
The wavelength selection switch obtains two optical comb lines from the optical frequency comb, wherein the interval between the two optical comb lines is 360GHz, one of the two optical comb lines is used as a local oscillator, and the other of the two optical comb lines is used as a carrier;
a second phase modulator obtains vector signals capable of loading precoding, and the vector signals are loaded on the carrier waves to obtain carrier waves loaded with signals;
the loadable precode vector signal refers to a signal capable of being directly modulated by a phase modulator, for example, the loadable precode vector signal may be, but is not limited to, a loadable precode 16 quadrature amplitude modulation QAM vector signal.
The first amplifier amplifies the carrier wave of the loading signal to obtain the carrier wave of the amplified loading signal;
the coupler couples the carrier wave of the amplified loading signal with the local oscillator to obtain a coupled signal;
the second amplifier amplifies the coupling signal to obtain an amplified coupling signal;
and the single-row carrier photoelectric detector carries out beat frequency on the amplified coupling signal to generate a terahertz wave signal.
Referring to fig. 5(b), on the basis of the two possible implementations, in yet another possible implementation, the chirp factor of one mach-zehnder modulator is obtained in the optical frequency comb generating circuit; according to a single-frequency light beam generated by a laser, a radio-frequency signal generated by a radio-frequency source and the chirp factor, two parallel phase modulators in the Mach-Zehnder modulator are driven by a radio-frequency driving voltage, and after an optical frequency comb is generated, the method further comprises the following steps:
the third amplifier amplifies the frequency of the optical frequency comb, and inputs the amplified signal to the wavelength selective switch as a new optical frequency comb;
the wavelength selective switch obtains two optical comb lines from the optical frequency comb, including:
and the wavelength selection switch obtains two optical frequency combs from the new optical frequency comb, wherein one optical comb line in the two optical frequency combs is used as a local oscillator, and the other optical comb line in the two optical frequency combs is used as a carrier.
Because the 16QAM vector signals can be modulated by directly using the phase modulator, but if the signals are not precoded, the signals are deformed and cannot be correctly demodulated, amplitude precoding and phase precoding are required to be performed on the 16QAM signals, and the 16QAM signals are preloaded on a radio frequency carrier, so as to obtain vector signals capable of loading precoding. The PM is then modulated using the vector signal loaded with the precoding. The 16QAM signal generated here is low-pass filtered, and then directly converted up to an RF (radio frequency signal) signal by the simultaneous action of a cosine function and a sine function.
In order to obtain the vector signal capable of being loaded with precoding, referring to fig. 6, the terahertz wave signal generating method based on the mach-zehnder modulator according to the embodiment of the present invention obtains the vector signal capable of being loaded with precoding by using the precoding module through the following steps:
the method comprises the first step of obtaining a pseudo-random binary sequence and a radio frequency carrier.
Wherein, the radio frequency carrier wave is different from the carrier wave generated by the frequency comb, and the radio frequency carrier wave f is s0 The signal is a sine signal or a cosine signal and is generated by matlab simulation software.
Secondly, performing 16QAM modulation on the pseudo-random binary sequence to obtain an I path signal and a Q path signal;
thirdly, amplitude precoding, phase precoding and quadrature modulation are respectively carried out on the I path signal and the Q path signal to obtain a precoded 16QAM vector signal, wherein the vector signal comprises: orthogonal I and Q signals;
fourthly, the orthogonal I path signal and the orthogonal Q path signal are respectively subjected to low-pass filtering and loaded on the radio frequency carrier wave to obtain a loaded I path signal and a loaded Q path signal;
wherein the frequency of the radio frequency signal here is about 5 GHz.
And fifthly, combining the loaded I path signals and the loaded Q path signals to obtain vector signals capable of loading precoding. As shown in fig. 6, in the fifth step, the first combiner and the second combiner load the I-path signal and the Q-path signal on the radio frequency carrier, respectively, and the third combiner combines the I-path signal and the Q-path signal loaded on the radio frequency carrier. And, referring to fig. 7(a), fig. 7(b) and fig. 7(c), the constellation before precoding, the constellation after only amplitude precoding, and the constellation after amplitude precoding and phase precoding are shown in sequence.
Compared with the related art, the method has the advantages that the IQ phase modulator is used, 16QAM vector signals can be directly loaded and sent to the UTC-PD (Uni-tracking-Carrier photodetector, UTC-PD for short), and the UTC-PD carries out processing. And, the IQ phase modulator comprises: two phase modulators and a phase shifter, wherein the two phase modulators connected in parallel are connected with the phase shifter.
In the embodiment of the invention, only one second phase modulator is adopted, and the second phase modulator is limited by the second phase modulator, so that the 16QAM vector signal cannot be directly loaded, and the pre-coding module is used for pre-coding the 16QAM vector signal and pre-loading the pre-coded 16QAM vector signal on a radio frequency carrier to obtain the pre-coded vector signal. Compared with the use of a plurality of devices of the IQ phase modulator, the complexity of a hardware circuit is reduced, so that the signal is modulated by the second phase modulator, the complexity of the system is effectively reduced, and the cost is reduced. Compared with the Q modulator, the cost is higher, the cost of the embodiment of the invention is lower, and the vector signal can be modulated.
In the embodiment of the invention, the 16QAM THz signal is experimentally evaluated through simulation. And the bit error rate was measured as a function of the transmitted optical power and successfully demonstrated performance below the FEC threshold. FIG. 8 is a graph showing the relationship between the bit error rate and the emitted optical power for a 5Gbaud 0.4THz 16QAM THz wave signal emitted to a PD. It can be seen that 20km of SMF-28 transmission results in optical power loss with an error rate of 3.8 e-3. The inset in fig. 8 shows the constellation of the 0.4THz36THz wave signal after the DSP was offline at-9 dBm optical power received. The optical frequency comb and the phase modulator are effectively combined, and the efficient and stable terahertz signal can be generated. Simulation experiment results show that the embodiment of the invention has certain practicability and feasibility.
Next, a description will be given of a terahertz wave signal generating apparatus based on a mach-zehnder modulator according to an embodiment of the present invention.
The embodiment of the invention provides a terahertz wave signal generating device based on a Mach-Zehnder modulator, which comprises the following modules:
the optical frequency comb generating circuit is used for acquiring the chirp factor of the Mach-Zehnder modulator; according to a single-frequency light beam generated by a laser, a radio-frequency signal generated by a radio-frequency source and the chirp factor, driving two phase modulators connected in parallel in the Mach-Zehnder modulator through a radio-frequency driving voltage to generate a light-frequency comb, wherein the radio-frequency driving voltage is equal to half of a half-wave voltage, and the Mach-Zehnder modulator is in an intensity modulation mode;
the wavelength selection switch is used for obtaining two optical comb lines from the optical frequency comb, wherein one of the two optical comb lines is used as a local oscillator, and the other of the two optical comb lines is used as a carrier;
a second phase modulator, configured to obtain a vector signal capable of being loaded with precoding, and load the vector signal onto the carrier to obtain a carrier loaded with a signal;
the first amplifier is used for amplifying the carrier of the loading signal to obtain the carrier of the amplified loading signal;
the coupler is used for coupling the carrier of the amplified loading signal with the local oscillator to obtain a coupled signal;
and the single-row carrier photoelectric detector is used for performing beat frequency on the coupling signal to generate a terahertz wave signal.
In one possible implementation, the chirp factor is 9;
the frequency interval between the optical frequency combs is 360GHz, and the frequency of a radio frequency signal of a radio frequency source is 30 GHz;
the interval between the two optical comb lines is 360GHz, one of the two optical comb lines is used as a local oscillator, and the other of the two optical comb lines is used as a carrier;
the frequency of the terahertz wave signal is 360 GHz.
In one possible implementation, the apparatus further includes: the precoding module is used for obtaining a vector signal capable of loading precoding by adopting the following steps:
acquiring a pseudo-random binary sequence and a radio frequency carrier;
carrying out 16QAM modulation on the pseudo-random binary sequence to obtain an I path signal and a Q path signal;
respectively carrying out amplitude precoding, phase precoding and quadrature modulation on the I path signal and the Q path signal to obtain a precoded 16QAM vector signal, wherein the vector signal comprises: orthogonal I and Q signals;
respectively low-pass filtering the orthogonal I path signal and Q path signal, and loading on the radio frequency carrier to obtain a loaded I path signal and a loaded Q path signal;
and combining the loaded I path signals and the loaded Q path signals to obtain vector signals capable of being loaded with precoding.
In one possible implementation, the apparatus further includes:
and the oscilloscope is used for displaying the terahertz wave signal after the single-row carrier photoelectric detector performs beat frequency on the coupling signal to generate the terahertz wave signal.
In one possible implementation, the optical-frequency comb generating circuit includes:
a radio frequency source for generating a radio frequency signal;
a laser for generating a single frequency beam;
one end of each of the two parallel phase modulators in the mach-zehnder modulator is used for inputting a radio frequency driving voltage and a direct current bias voltage, the two parallel phase modulators are driven to respectively perform phase modulation on the radio frequency signal to generate an optical frequency comb, and the other end of each of the two parallel phase modulators in the mach-zehnder modulator is used for outputting the optical frequency comb.
In one possible implementation, the apparatus further includes:
a third amplifier for obtaining a chirp factor of a mach-zehnder modulator at the optical-frequency comb generating circuit; according to a single-frequency light beam generated by a laser, a radio-frequency signal generated by a radio-frequency source and the chirp factor, driving two phase modulators connected in parallel in the Mach-Zehnder modulator through a radio-frequency driving voltage, generating an optical frequency comb, then amplifying the frequency of the optical frequency comb, and inputting the amplified signal serving as a new optical frequency comb to the wavelength selection switch;
and the wavelength selection switch is used for obtaining two optical frequency combs from the new optical frequency comb, wherein one optical comb line of the two optical frequency combs is used as a local oscillator, and the other optical comb line of the two optical frequency combs is used as a carrier wave.
It is noted that, herein, relational terms such as first and second, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other identical elements in a process, method, article, or apparatus that comprises the element.
All the embodiments in the present specification are described in a related manner, and the same and similar parts among the embodiments may be referred to each other, and each embodiment focuses on the differences from the other embodiments. In particular, for the apparatus embodiment, since it is substantially similar to the method embodiment, the description is relatively simple, and reference may be made to the partial description of the method embodiment for relevant points.
The above description is only for the preferred embodiment of the present invention, and is not intended to limit the scope of the present invention. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention shall fall within the protection scope of the present invention.
Claims (7)
1. A terahertz wave signal generation method based on a precoded Mach-Zehnder modulator is characterized by comprising the following steps:
the optical frequency comb generating circuit acquires a chirp factor of a Mach-Zehnder modulator; according to a single-frequency light beam generated by a laser, a radio-frequency signal generated by a radio-frequency source and the chirp factor, driving two phase modulators connected in parallel in the Mach-Zehnder modulator through a radio-frequency driving voltage to generate a light-frequency comb, wherein the radio-frequency driving voltage is equal to half of a half-wave voltage, and the Mach-Zehnder modulator is in an intensity modulation mode;
the wavelength selection switch obtains two optical comb lines from the optical frequency comb, wherein one of the two optical comb lines is used as a local oscillator, and the other of the two optical comb lines is used as a carrier;
a second phase modulator obtains vector signals capable of loading precoding, and the vector signals are loaded on the carrier waves to obtain carrier waves loaded with signals;
the first amplifier amplifies the carrier wave of the loading signal to obtain the carrier wave of the amplified loading signal;
the coupler couples the carrier of the amplified loading signal with the local oscillator to obtain a coupled signal;
the single-row carrier photoelectric detector beats the coupling signal to generate a terahertz wave signal;
the vector signal capable of loading precoding is obtained by a precoding module through the following steps:
acquiring a pseudo-random binary sequence and a radio frequency carrier;
carrying out 16QAM modulation on the pseudo-random binary sequence to obtain an I path signal and a Q path signal;
respectively carrying out amplitude precoding, phase precoding and quadrature modulation on the I path signal and the Q path signal to obtain a precoded 16QAM vector signal, wherein the vector signal comprises: orthogonal I and Q signals;
respectively low-pass filtering the orthogonal I path signal and Q path signal, and loading on the radio frequency carrier to obtain a loaded I path signal and a loaded Q path signal;
combining the loaded I path signals and the loaded Q path signals to obtain vector signals capable of being loaded with precoding;
the optical frequency comb generating circuit acquires a chirp factor of a Mach-Zehnder modulator; according to a single-frequency light beam generated by a laser, a radio-frequency signal generated by a radio-frequency source and the chirp factor, two parallel phase modulators in the Mach-Zehnder modulator are driven by a radio-frequency driving voltage to generate an optical frequency comb, and the method comprises the following steps:
a radio frequency signal generated by a radio frequency source;
a single frequency beam generated by a laser;
and one end of each of two parallel phase modulators in the Mach-Zehnder modulator inputs radio frequency driving voltage and direct current bias voltage, the two parallel phase modulators are driven to respectively perform phase modulation on the radio frequency signals to generate an optical frequency comb, and the other end of each of the two parallel phase modulators in the Mach-Zehnder modulator outputs the optical frequency comb.
2. The method of claim 1, wherein the chirp factor is 9;
the frequency interval between the optical frequency combs is 360GHz, and the frequency of a radio frequency signal of a radio frequency source is 30 GHz;
the interval between the two optical comb lines is 360GHz, one of the two optical comb lines is used as a local oscillator, and the other of the two optical comb lines is used as a carrier;
the frequency of the terahertz wave signal is 360 GHz.
3. The method of claim 1 or 2, wherein after the single-file carrier photodetector beats the coupled signal generating a terahertz wave signal, the method further comprises:
and displaying the terahertz wave signal by an oscilloscope.
4. The method of claim 1 or 2, wherein the coupler couples the carrier of the amplified loading signal with the local oscillator to obtain a coupled signal, and further comprising:
the second amplifier amplifies the coupling signal to obtain an amplified coupling signal;
and the single-row carrier photoelectric detector carries out beat frequency on the amplified coupling signal to generate a terahertz wave signal.
5. The method according to claim 1 or 2, wherein a chirp factor of a mach-zehnder modulator is obtained at the optical-frequency comb generating circuit; after two parallel phase modulators in the mach-zehnder modulator are driven by a radio-frequency driving voltage according to a single-frequency light beam generated by a laser, a radio-frequency signal generated by a radio-frequency source and the chirp factor to generate an optical-frequency comb, the method further comprises:
the third amplifier amplifies the frequency of the optical frequency comb, and inputs the amplified signal to the wavelength selective switch as a new optical frequency comb;
the wavelength selective switch obtains two optical comb lines from the optical frequency comb, including:
and the wavelength selection switch obtains two optical frequency combs from the new optical frequency comb, wherein one optical comb line in the two optical frequency combs is used as a local oscillator, and the other optical comb line in the two optical frequency combs is used as a carrier.
6. A terahertz wave signal generating apparatus based on a precoded mach-zehnder modulator, characterized by comprising:
the optical frequency comb generating circuit is used for acquiring the chirp factor of the Mach-Zehnder modulator; according to a single-frequency light beam generated by a laser, a radio-frequency signal generated by a radio-frequency source and the chirp factor, driving two phase modulators connected in parallel in the Mach-Zehnder modulator through a radio-frequency driving voltage to generate a light-frequency comb, wherein the radio-frequency driving voltage is equal to half of a half-wave voltage, and the Mach-Zehnder modulator is in an intensity modulation mode;
the wavelength selection switch is used for obtaining two optical comb lines from the optical frequency comb, wherein one of the two optical comb lines is used as a local oscillator, and the other of the two optical comb lines is used as a carrier;
a second phase modulator, configured to obtain a vector signal capable of being loaded with precoding, and load the vector signal on the carrier to obtain a carrier loaded with a signal;
the first amplifier is used for amplifying the carrier of the loading signal to obtain the carrier of the amplified loading signal;
the coupler is used for coupling the carrier of the amplified loading signal with the local oscillator to obtain a coupled signal;
the single-row carrier photoelectric detector is used for performing beat frequency on the coupling signal to generate a terahertz wave signal;
the precoding module is used for obtaining a vector signal capable of loading precoding by adopting the following steps:
acquiring a pseudo-random binary sequence and a radio frequency carrier;
carrying out 16QAM modulation on the pseudo-random binary sequence to obtain an I path signal and a Q path signal;
respectively carrying out amplitude precoding, phase precoding and quadrature modulation on the I path signal and the Q path signal to obtain a precoded 16QAM vector signal, wherein the vector signal comprises: orthogonal I and Q signals;
respectively low-pass filtering the orthogonal I path signal and the orthogonal Q path signal, and loading the signals on the radio frequency carrier to obtain a loaded I path signal and a loaded Q path signal;
combining the loaded I path signals and the loaded Q path signals to obtain vector signals capable of being loaded with precoding;
the optical frequency comb generation circuit is specifically used for: a radio frequency signal generated by a radio frequency source; a single frequency beam generated by a laser; and one end of each of two phase modulators connected in parallel in the Mach-Zehnder modulator inputs a radio frequency driving voltage and a direct current bias voltage, the two phase modulators connected in parallel are driven to respectively perform phase modulation on the radio frequency signals to generate an optical frequency comb, and the other end of each of the two phase modulators connected in parallel in the Mach-Zehnder modulator outputs the optical frequency comb.
7. The apparatus of claim 6, wherein the chirp factor is 9;
the frequency interval between the optical frequency combs is 360GHz, and the frequency of a radio frequency signal of a radio frequency source is 30 GHz;
the interval between the two optical comb lines is 360GHz, one of the two optical comb lines is used as a local oscillator, and the other of the two optical comb lines is used as a carrier;
the frequency of the terahertz wave signal is 360 GHz.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202011292849.2A CN112415829B (en) | 2020-11-18 | 2020-11-18 | Terahertz wave signal generation method and device based on Mach-Zehnder modulator |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202011292849.2A CN112415829B (en) | 2020-11-18 | 2020-11-18 | Terahertz wave signal generation method and device based on Mach-Zehnder modulator |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN112415829A CN112415829A (en) | 2021-02-26 |
| CN112415829B true CN112415829B (en) | 2022-09-30 |
Family
ID=74772943
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202011292849.2A Active CN112415829B (en) | 2020-11-18 | 2020-11-18 | Terahertz wave signal generation method and device based on Mach-Zehnder modulator |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN112415829B (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112994803B (en) * | 2021-02-19 | 2022-02-08 | 西安邮电大学 | Photon auxiliary vector terahertz signal communication system |
| CN113067643B (en) * | 2021-03-22 | 2022-09-30 | 中国电子科技集团公司第十四研究所 | MZM bias point control method of EDFA-containing optical link |
| CN115479914B (en) * | 2022-08-15 | 2023-06-27 | 北京邮电大学 | High-resolution terahertz frequency domain scanning system and method |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106027153A (en) * | 2016-05-12 | 2016-10-12 | 西安电子科技大学 | Method for generating 60GHz millimeter waves based on new double-sideband Mach-Zehnder modulator |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108712214B (en) * | 2018-05-08 | 2019-10-18 | 浙江大学 | A kind of tunable mostly band terahertz pulse wireless communication emitter |
| CN109743115B (en) * | 2018-12-05 | 2022-02-08 | 南京邮电大学 | MZM-based microwave frequency comb generation device and method of numerical control optical heterodyne method |
| CN110224764B (en) * | 2019-06-13 | 2021-08-20 | 复旦大学 | Method for generating vector terahertz signal by using PM and IM based on ISB and multi-carrier |
| CN111541492A (en) * | 2020-04-24 | 2020-08-14 | 咸阳师范学院 | Multichannel expanded ultra-wideband radio-frequency channelized receiving device and implementation method |
-
2020
- 2020-11-18 CN CN202011292849.2A patent/CN112415829B/en active Active
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106027153A (en) * | 2016-05-12 | 2016-10-12 | 西安电子科技大学 | Method for generating 60GHz millimeter waves based on new double-sideband Mach-Zehnder modulator |
Also Published As
| Publication number | Publication date |
|---|---|
| CN112415829A (en) | 2021-02-26 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN112415829B (en) | Terahertz wave signal generation method and device based on Mach-Zehnder modulator | |
| US7761012B2 (en) | Optical communication system and method for generating dark return-to zero and DWDM optical MM-Wave generation for ROF downstream link using optical phase modulator and optical interleaver | |
| Li et al. | Photonic vector signal generation at W-band employing an optical frequency octupling scheme enabled by a single MZM | |
| CN108199776B (en) | Microwave photon up-conversion device and method based on photoelectric oscillator | |
| CN105099570A (en) | Orthogonal multi-carrier light source and PDM-QPSK signal transmitting device | |
| CN110011174B (en) | Optical phase locking method and device based on microwave photon frequency division | |
| US10164711B2 (en) | Optical mm-wave signal generation using a single IQ modulator | |
| CN110958053B (en) | Device and method for generating quad-frequency optical millimeter wave BPSK vector signal | |
| KR102503881B1 (en) | Terahertz signal transmission apparatus and terahertz signal transmission method using the same | |
| US10181909B2 (en) | Method and apparatus for optical wireless architecture | |
| Ghafoor et al. | Sub-carrier-multiplexed duplex 64-QAM radio-over-fiber transmission for distributed antennas | |
| Chen et al. | A filterless 24-tupling optical millimeter-wave generation and RoF distribution | |
| Zhu et al. | Optical millimeter-wave signal generation by frequency quadrupling using one dual-drive Mach–Zehnder modulator to overcome chromatic dispersion | |
| CN112564813B (en) | Precoding-based terahertz wave signal generation method and device of phase modulator | |
| WO2018198873A1 (en) | Optical transmission method and optical transmission device | |
| Kamissoko et al. | Performance investigation of W-band millimeter-wave radio-over-fiber system employing optical heterodyne generation and self-homodyne detection | |
| Yu et al. | Terahertz-wave generation based on optical frequency comb and single Mach-Zehnder modulator | |
| Li et al. | 0.36 THz photonic terahertz-wave generation by simple optical frequency comb | |
| CN111965915A (en) | Terahertz wave signal generation system and method based on optical frequency comb | |
| Kanno et al. | Phase noise analysis of an optical frequency comb using single side-band suppressed carrier modulation in an amplified optical fiber loop | |
| Ma et al. | A novel ROF link scheme with frequency quadrupling optical millimeter-wave carrying dual-stream of 10 Gbit/s 16-QAM signals | |
| Zacharias et al. | Full duplex millimeter-wave Radio-Over-Fiber system using optical heterodyning and self-homodyning | |
| Parajuli et al. | Optimization of optical carrier to sideband ratio for the concatenated AM-PM based optical single sideband radio over fiber system | |
| Li et al. | Flexible photonic generation of frequency multiplication millimeter-wave vector signal based on dynamic pre-coding algorithm with dispersion compensation | |
| Bahrami et al. | A full-duplex optical millimeter waves (60-100 GHz) radio-over-fiber system |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |