Terahertz signal mixing device and method based on microwave photon technology
By using a terahertz signal mixing device based on microwave photonics technology, mixing is achieved through optical signal interference and modulation, which solves the problems of system bandwidth and complexity of traditional electronic mixers and realizes terahertz signal processing with high integration and low loss.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-03
- Publication Date
- 2026-04-14
AI Technical Summary
Traditional terahertz signal mixers based on electronics suffer from problems such as difficulty in increasing system bandwidth, high cost, high loss, system complexity, and large size, making it difficult to meet the development needs of terahertz systems.
A terahertz signal mixing device based on microwave photonics technology is adopted. It utilizes a seed laser, a phase modulator, a signal generator, an optical coupler, a slave laser, an erbium-doped fiber amplifier, optoelectronic semiconductor devices, a coplanar probe, a terahertz signal generator, a DC biaser, a DC voltage source, and a signal analyzer to achieve mixing through phase modulation and optical signal interference, thereby reducing the physical size and complexity of the system.
It achieves ultra-wideband tunability, low loss, strong electromagnetic interference resistance, and high system integration, greatly reducing physical size and complexity, and is easy to integrate with other semiconductor devices.
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Figure CN121864207A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of terahertz signal mixing technology, and in particular to a terahertz signal mixing device and method based on microwave photonics technology. Background Technology
[0002] The terahertz band typically refers to a segment of electromagnetic waves in the electromagnetic spectrum with a frequency range of 0.1 THz to 10 THz and a wavelength range of 30 μm to 3 mm. The terahertz band lies between the short-wavelength edge of millimeter waves and the long-wavelength edge of infrared light in the electromagnetic spectrum. From the perspective of its spectral range, compared to microwaves and millimeter waves, terahertz waves have a higher frequency and shorter wavelength, enabling electronic devices to have larger communication bandwidth, higher resolution, and to achieve miniaturization and weight reduction. Compared to ordinary visible light, terahertz waves have better penetration through many non-polar materials (wood, plastics, fabrics, smoke, etc.), improving the ability of electronic testing equipment to detect these materials through light. Furthermore, the photon energy of terahertz waves is very low (only on the order of meV), posing no harm to humans or other living organisms, allowing for non-destructive testing and biomedical imaging using terahertz waves. Due to its unique optical properties, terahertz waves have attracted great attention in recent decades. Currently, terahertz waves have been widely studied and applied in various fields, including material detection, airport and railway station security inspection, non-destructive testing of materials, industrial control, broadband terahertz communication, material terahertz spectrum analysis, biomedical diagnosis, space exploration, radar, electronic countermeasures, and metrology, which have a strong driving effect on scientific research, national economy and social development.
[0003] As an important component for signal processing in terahertz systems, mixers are widely used in satellite communications, wireless communications, and radar. Traditional electronics-based terahertz signal mixers have very serious bottlenecks, making it increasingly difficult to increase system bandwidth. In addition, high-speed electronic devices are expensive, have high losses, are complex, and are bulky, making it difficult to meet the development needs of terahertz systems.
[0004] Therefore, improving integration and reducing the physical size and complexity of the system has become one of the urgent existing technical problems to be solved. Summary of the Invention
[0005] This invention provides a terahertz signal mixing device and method based on microwave photonics technology, which can improve integration and reduce the physical size and complexity of the system.
[0006] In a first aspect, a terahertz signal mixing device based on microwave photonics technology is provided, comprising: a seed laser, a phase modulator, a signal generator, an optical coupler, a slave laser, an erbium-doped fiber amplifier, optoelectronic semiconductor devices, a coplanar probe, a terahertz signal generator, a DC biaser, a DC voltage source, and a signal analyzer; wherein...
[0007] The seed laser is used to output a continuous laser signal; the phase modulator is used to perform phase modulation on the laser signal output by the seed laser to obtain a main laser frequency comb; the signal generator is used to provide the modulation signal.
[0008] The slave laser is used to interfere with the optical signal passing through the optical coupler and the laser signal generated by the slave laser, so that the output light of the two are coherent and have consistent phase and frequency.
[0009] The terahertz signal generator generates a terahertz signal which is fed into an optoelectronic semiconductor device via a coplanar probe and mixed with the local oscillator signal generated by the optoelectronic semiconductor device to obtain an intermediate frequency signal.
[0010] In one embodiment, the optical signal, after being phase-modulated by the phase modulator, is split into two paths after passing through the first optical coupler and input into two slave lasers respectively.
[0011] In one embodiment, the two laser signals output from the slave laser pass through a second optical coupler to obtain an optical signal, which is then amplified by an erbium-doped fiber amplifier and input to an optoelectronic semiconductor device to excite the optoelectronic semiconductor device to generate a local oscillator signal.
[0012] In one implementation, during the terahertz signal mixing process, a DC voltage source is used to provide a bias voltage to the optoelectronic semiconductor device through a DC biaser to adjust its operating state.
[0013] In one embodiment, the intermediate frequency signal obtained by the optoelectronic semiconductor device is input into a signal analyzer for detection after passing through a coplanar probe and a T-type DC bias.
[0014] In one embodiment, the optoelectronic semiconductor device is a waveguide-fed traveling-wave unidirectional carrier photodiode.
[0015] In one embodiment, the optoelectronic semiconductor device employs a coplanar waveguide structure, utilizing an InGaAs absorption layer and an InP carrier collection layer to optimize electron transport.
[0016] In one embodiment, the optoelectronic semiconductor device is manufactured using standard photolithography and wet etching processes, and the absorption layer is grown by metal-organic vapor phase epitaxy (MOVPE) to achieve gradient doping.
[0017] Secondly, a terahertz signal mixing method based on microwave photonics technology is provided, the method being applied to the aforementioned apparatus, comprising:
[0018] The seed laser outputs a continuous laser signal, and the main laser frequency comb is obtained by using a phase modulator to modulate the phase of the laser signal.
[0019] After the phase-modulated optical signal passes through the optical coupler, it is split into two paths and input into two slave lasers respectively. The optical signal interferes with the laser signal generated by the slave laser, making the output light of the two coherent and having consistent phase and frequency.
[0020] The two laser signals output from the slave laser are amplified by an erbium-doped fiber amplifier after passing through an optical coupler, and then input to an optoelectronic semiconductor device to excite the device to generate a local oscillator signal.
[0021] The terahertz signal generated by the terahertz signal generator is fed into the optoelectronic semiconductor device through a coplanar probe and mixed with the local oscillator signal to achieve frequency mixing. The resulting intermediate frequency signal is then fed into the signal analyzer for detection after passing through the coplanar probe and a T-type DC bias.
[0022] In one implementation, during the terahertz signal mixing process, a DC voltage source is used to provide a bias voltage to the optoelectronic semiconductor device through a DC biaser to adjust its operating state.
[0023] This invention provides a terahertz signal mixing device and method based on microwave photonics technology. The device includes: a seed laser, a phase modulator, a signal generator, an optical coupler, a slave laser, an erbium-doped fiber amplifier, an optoelectronic semiconductor device, a coplanar probe, a terahertz signal generator, a DC biaser, a DC voltage source, and a signal analyzer. The seed laser outputs a continuous laser signal. The phase modulator modulates the laser signal output from the seed laser to obtain a master laser frequency comb. The signal generator provides a modulation signal. The slave laser interferes with the optical signal generated by the optical coupler and the laser signal generated by the slave laser, ensuring coherence and consistency in phase and frequency. The terahertz signal generator feeds the generated terahertz signal through the coplanar probe into the optoelectronic semiconductor device, where it mixes with the local oscillator signal generated by the device to obtain an intermediate frequency signal. This device improves integration and reduces the physical size and complexity of the system.
[0024] Other features and advantages of the invention will be set forth in the following description, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention may be realized and obtained by means of the structures particularly pointed out in the written description, claims, and accompanying drawings. Attached Figure Description
[0025] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this invention, illustrate exemplary embodiments of the invention and are used to explain the invention, but do not constitute an undue limitation of the invention. In the drawings:
[0026] Figure 1 This is a block diagram of a terahertz signal mixing device based on microwave photonics technology according to an embodiment of the present invention;
[0027] Figure 2 This is a structural diagram of a waveguide-fed traveling wave unidirectional carrier photodiode according to an embodiment of the present invention. Detailed Implementation
[0028] To improve integration and reduce the physical size and complexity of the system, a terahertz signal mixing device and method based on microwave photonics technology is provided.
[0029] The preferred embodiments of the present invention will be described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are for illustration and explanation only and are not intended to limit the present invention. Furthermore, the embodiments and features in the embodiments of the present invention can be combined with each other without conflict.
[0030] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of the embodiments of the present invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments described herein can be implemented in a sequence other than that illustrated or described herein.
[0031] like Figure 1 As shown in the embodiment, a terahertz signal mixing device based on microwave photonics technology is provided, including: a seed laser, a phase modulator, a signal generator, an optical coupler, a slave laser, an erbium-doped fiber amplifier, optoelectronic semiconductor devices, a coplanar probe, a terahertz signal generator, a DC biaser, a DC voltage source, and a signal analyzer; wherein,
[0032] The seed laser is used to output a continuous laser signal; the phase modulator is used to perform phase modulation on the laser signal output by the seed laser to obtain a main laser frequency comb; the signal generator is used to provide the modulation signal.
[0033] The slave laser is used to interfere with the optical signal passing through the optical coupler and the laser signal generated by the slave laser, so that the output light of the two are coherent and have consistent phase and frequency.
[0034] The terahertz signal generator generates a terahertz signal which is fed into an optoelectronic semiconductor device via a coplanar probe and mixed with the local oscillator signal generated by the optoelectronic semiconductor device to obtain an intermediate frequency signal.
[0035] In one embodiment, the optical signal, after being phase-modulated by the phase modulator, is split into two paths after passing through the first optical coupler and input into two slave lasers respectively.
[0036] In one embodiment, the two laser signals output from the slave laser pass through a second optical coupler to obtain an optical signal, which is then amplified by an erbium-doped fiber amplifier and input to an optoelectronic semiconductor device to excite the optoelectronic semiconductor device to generate a local oscillator signal.
[0037] In one implementation, during the terahertz signal mixing process, a DC voltage source is used to provide a bias voltage to the optoelectronic semiconductor device through a DC biaser to adjust its operating state.
[0038] In one embodiment, the intermediate frequency signal obtained by the optoelectronic semiconductor device is input into a signal analyzer for detection after passing through a coplanar probe and a T-type DC bias.
[0039] In one implementation, such as Figure 2 As shown, the optoelectronic semiconductor device is a waveguide-fed traveling wave unidirectional carrier photodiode. It adopts a coplanar waveguide structure and utilizes an InGaAs absorption layer and an InP carrier collection layer to optimize electron transport. It is manufactured using standard photolithography and wet etching processes and grown by metal-organic vapor phase epitaxy (MOVPE) to achieve gradient doping of the absorption layer.
[0040] Based on the same technical concept, this application also provides a terahertz signal mixing method based on microwave photonics technology. Since the method is applied to the above-mentioned device, the implementation of the method can refer to the implementation of the device, and repeated parts will not be described again.
[0041] To make it easier to understand, a specific example is given below:
[0042] Based on microwave photonics technology, such as Figure 1As shown, the seed laser outputs a continuous laser signal with a wavelength of 1550 nm. A phase modulator is used to phase modulate this laser signal to obtain a master laser frequency comb. The modulation signal frequency is 20 GHz, provided by a signal generator. The phase-modulated optical signal is split into two paths after passing through a first optical coupler and input to two slave lasers respectively. The laser signal frequencies output by the first and second slave lasers are f1 and f2, respectively. The phase-modulated optical signal interferes with the laser signals generated by the slave lasers, making the output light coherent and consistent in phase and frequency. This method can improve the stability of the slave laser output signal. The two laser signals output by the slave lasers are then processed by a second optical coupler to obtain a frequency of f1. LO An optical signal with a frequency of f1-f2 = 100 GHz is amplified by an erbium-doped fiber amplifier and then input into a photoelectric semiconductor device to excite the device to generate a local oscillator signal with a frequency of 100 GHz. Specifically, a unidirectional transport carrier photodiode integrated with a coplanar waveguide can be used as the photoelectric semiconductor device. The terahertz signal generated by the terahertz signal generator is fed into the photoelectric semiconductor device via a coplanar probe and mixed with the local oscillator signal. The resulting intermediate frequency signal is then input into a signal analysis instrument for detection after passing through the coplanar probe and a T-type DC biaser. During the terahertz signal mixing process, a DC voltage source is used to provide a bias voltage to the photoelectric semiconductor device through a DC biaser to adjust its operating state.
[0043] In particular, the present invention employs Figure 2 The waveguide-fed traveling-wave unidirectional carrier photodiode shown is a photoelectric semiconductor device. This device employs a coplanar waveguide structure, utilizing an InGaAs absorption layer and an InP carrier collection layer to optimize electron transport. The device is fabricated using standard photolithography and wet etching processes, and the absorption layer is grown via metal-organic vapor phase epitaxy (MOVPE) to achieve gradient doping. The excitation optical signal is incident through a tapered waveguide aperture and coupled to the intermediate waveguide to achieve mode field diameter matching of the lens fiber.
[0044] An embodiment provides a terahertz signal mixing method based on microwave photonics technology, including:
[0045] The seed laser outputs a continuous laser signal, and the main laser frequency comb is obtained by using a phase modulator to modulate the phase of the laser signal.
[0046] After the phase-modulated optical signal passes through the optical coupler, it is split into two paths and input into two slave lasers respectively. The optical signal interferes with the laser signal generated by the slave laser, making the output light of the two coherent and having consistent phase and frequency.
[0047] The two laser signals output from the slave laser are amplified by an erbium-doped fiber amplifier after passing through an optical coupler, and then input to an optoelectronic semiconductor device to excite the device to generate a local oscillator signal.
[0048] The terahertz signal generated by the terahertz signal generator is fed into the optoelectronic semiconductor device through a coplanar probe and mixed with the local oscillator signal to achieve frequency mixing. The resulting intermediate frequency signal is then fed into the signal analyzer for detection after passing through the coplanar probe and a T-type DC bias.
[0049] In one implementation, during the terahertz signal mixing process, a DC voltage source is used to provide a bias voltage to the optoelectronic semiconductor device through a DC biaser to adjust its operating state.
[0050] To make it easier to understand, a specific example is given below:
[0051] The seed laser outputs a continuous laser signal with a wavelength of 1550nm. The laser signal is phase-modulated by a phase modulator to obtain the main laser frequency comb. The modulation signal frequency is 20GHz and is provided by the signal generator.
[0052] The phase-modulated optical signal is split into two paths after passing through the first optical coupler and input into two slave lasers respectively. The laser signal frequencies output by the first slave laser and the second slave laser are f1 and f2 respectively. The phase-modulated optical signal interferes with the laser signal generated by the slave laser, making the output light of the two coherent and consistent in phase and frequency. This method can improve the stability of the output optical signal of the slave laser.
[0053] The two laser signals output from the slave laser are coupled to a frequency of f after passing through a second optical coupler. LO An optical signal with a frequency of 100 GHz (f1-f2) is amplified by an erbium-doped fiber amplifier and then input into an optoelectronic semiconductor device to excite the device to generate a local oscillator signal with a frequency of 100 GHz.
[0054] The terahertz signal generated by the terahertz signal generator is fed into the optoelectronic semiconductor device through a coplanar probe and mixed with the local oscillator signal to achieve frequency mixing. The obtained intermediate frequency signal is then input into the signal analyzer for detection after passing through the coplanar probe and the T-type DC bias.
[0055] During the mixing process of terahertz signals, a DC voltage source is used to provide bias voltage to optoelectronic semiconductor devices through a DC biaser, which is used to adjust their operating state.
[0056] The key advantages of the terahertz signal mixing scheme based on microwave photonics technology proposed in this invention compared to traditional electronic mixing methods mainly include:
[0057] 1. Terahertz mixing systems based on microwave photonics technology have several advantages over traditional electronic mixing systems, including ultra-wideband tunability, low loss, and strong resistance to electromagnetic interference.
[0058] 2. Using a single semiconductor device as both a local oscillator signal generator and a terahertz signal mixer provides high integration and significantly reduces the physical size and complexity of the system.
[0059] 3. The terahertz mixer proposed in this invention is easy to integrate with other silicon-based and indium phosphide-based semiconductor devices, and has great application prospects in the field of terahertz optoelectronics.
[0060] Although preferred embodiments of the invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of the invention.
[0061] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.
Claims
1. A terahertz signal mixing device based on microwave photonics technology, characterized in that, include: Seed lasers, phase modulators, signal generators, optocouplers, slave lasers, erbium-doped fiber amplifiers, optoelectronic semiconductor devices, coplanar probes, terahertz signal generators, DC biasers, DC voltage sources, and signal analyzers; among them, The seed laser is used to output a continuous laser signal; the phase modulator is used to perform phase modulation on the laser signal output by the seed laser to obtain a main laser frequency comb; the signal generator is used to provide the modulation signal. The slave laser is used to interfere with the optical signal passing through the optical coupler and the laser signal generated by the slave laser, so that the output light of the two are coherent and have consistent phase and frequency. The terahertz signal generator generates a terahertz signal which is fed into an optoelectronic semiconductor device via a coplanar probe and mixed with the local oscillator signal generated by the optoelectronic semiconductor device to obtain an intermediate frequency signal.
2. The terahertz signal mixing device based on microwave photonics technology according to claim 1, characterized in that, The optical signal, after being phase modulated by the phase modulator, is split into two paths after passing through the first optical coupler and input into the two slave lasers respectively.
3. The terahertz signal mixing device based on microwave photonics technology according to claim 2, characterized in that, The two laser signals output from the slave laser are converted into optical signals by the second optical coupler. These signals are then amplified by an erbium-doped fiber amplifier and input to an optoelectronic semiconductor device to excite the device to generate a local oscillator signal.
4. The terahertz signal mixing device based on microwave photonics technology according to claim 3, characterized in that, During the mixing process of terahertz signals, a DC voltage source is used to provide bias voltage to optoelectronic semiconductor devices through a DC biaser, which is used to adjust their operating state.
5. The terahertz signal mixing device based on microwave photonics technology according to claim 4, characterized in that, The intermediate frequency signal obtained by the optoelectronic semiconductor device is input into the signal analyzer for detection after passing through a coplanar probe and a T-type DC bias.
6. The terahertz signal mixing device based on microwave photonics technology according to claim 5, characterized in that, The optoelectronic semiconductor device is a waveguide-fed traveling-wave unidirectional carrier photodiode.
7. The terahertz signal mixing device based on microwave photonics technology according to claim 6, characterized in that, The optoelectronic semiconductor device adopts a coplanar waveguide structure and utilizes an InGaAs absorption layer and an InP carrier collection layer to optimize electron transport.
8. The terahertz signal mixing device based on microwave photonics technology according to claim 7, characterized in that, The optoelectronic semiconductor device is manufactured using standard photolithography and wet etching processes, and the absorption layer is grown using metal-organic vapor phase epitaxy (MOVPE) to achieve gradient doping.
9. A method for using the terahertz signal mixing device based on microwave photonics technology as described in claims 1-8, characterized in that, include: The seed laser outputs a continuous laser signal, and the main laser frequency comb is obtained by using a phase modulator to modulate the phase of the laser signal. After the phase-modulated optical signal passes through the optical coupler, it is split into two paths and input into two slave lasers respectively. The optical signal interferes with the laser signal generated by the slave laser, making the output light of the two coherent and having consistent phase and frequency. The two laser signals output from the slave laser are amplified by an erbium-doped fiber amplifier after passing through an optical coupler, and then input to an optoelectronic semiconductor device to excite the device to generate a local oscillator signal. The terahertz signal generated by the terahertz signal generator is fed into the optoelectronic semiconductor device through a coplanar probe and mixed with the local oscillator signal to achieve frequency mixing. The resulting intermediate frequency signal is then fed into the signal analyzer for detection after passing through the coplanar probe and a T-type DC bias.
10. The terahertz signal mixing method based on microwave photonics technology according to claim 9, characterized in that, During the mixing process of terahertz signals, a DC voltage source is used to provide bias voltage to optoelectronic semiconductor devices through a DC biaser, which is used to adjust their operating state.