CN-122027038-A - Terahertz noise signal generation device and system based on multi-beam tunable chaotic light mixing

CN122027038ACN 122027038 ACN122027038 ACN 122027038ACN-122027038-A

Abstract

The invention provides a terahertz noise signal generating device and system based on multi-beam tunable chaotic light mixing, which relate to the technical field of terahertz noise signal generation and comprise a multi-wavelength laser array, a circulator, an optical coupler, a variable optical attenuator, a polarization controller and a photoelectric detector. The multi-wavelength laser array outputs a beam of multi-wavelength continuous light with uniform wavelength intervals by independently regulating and controlling current parameters of n unit lasers, the beam is directionally transmitted to the optical coupler through the circulator, and the optical coupler splits the light into a feedback branch and a signal branch. In the feedback branch, continuous light is re-injected into the multi-wavelength laser array through the variable optical attenuator and the polarization controller and through the optical circulator, and the inherent relaxation oscillation of the laser generates chaotic light through the instability of oscillation amplitude and the frequency spectrum broadening of the inherent relaxation oscillation under the disturbance of external optical feedback. In the signal branch, n bundles of chaotic light are transmitted to the photoelectric detector, and terahertz noise signals with flat frequency spectrum and high super-noise ratio can be generated through an optical mixing process.

Inventors

MA YUXIN
LI PU
WANG YUNCAI
GAO JUNJIAN
SUN YUEHUI
LIU WENJIE

Assignees

广东工业大学

Dates

Publication Date: 20260512
Application Date: 20260116

Claims (10)

1. The terahertz noise signal generating device based on multi-beam tunable chaotic light mixing is characterized by comprising a multi-wavelength laser array (1), a circulator (2), an optical coupler (3), a variable optical attenuator (4), a polarization controller (5) and a photoelectric detector (6); The multi-wavelength laser array (1) is internally provided with a plurality of independent laser units, each laser unit and the adjacent laser units are preset with fixed wavelength intervals, each laser unit independently carries out working current adjustment, the central wavelength of the laser unit is changed to change the frequency range of the terahertz noise spectrum, and the multi-wavelength laser array (1) outputs n wavelengths of laser to a first port of the circulator (2), outputs from a second port of the circulator (2) and enters the optical coupler (3); The first output end of the optical coupler (3) is connected with the input end of the variable optical attenuator (4), the output end of the variable optical attenuator (4) is connected with the input end of the polarization controller (5), the output end of the polarization controller (5) is connected with the third port of the circulator (2) to form a feedback branch, the variable optical attenuator (4) regulates and controls the power intensities of the n wavelengths of laser to a chaotic state triggering threshold value, the polarization controller (5) changes the polarization state of an initial laser signal, and the laser signal regulated and controlled by the variable optical attenuator (4) and the polarization controller (5) is directionally transmitted by the circulator (2) and then is output from the first port and is input into the multi-wavelength laser array (1) to form external optical feedback disturbance, so that the multi-wavelength laser array (1) enters the chaotic state; The signal output end of the optical coupler (3) is connected with the input end of the photoelectric detector (6) to form a signal branch, and the photoelectric detector (6) carries out electro-optic conversion on n bundles of chaotic laser on the signal branch, and outputs broadband terahertz signals through optical mixing.
2. The terahertz noise signal generating device based on multi-beam tunable chaotic light mixing according to claim 1, wherein the n wavelength lasers output from the second port of the circulator (2) and entering the optical coupler (3) are split into a first part of light and a second part of light according to a preset proportion through the first output end of the optical coupler (3), the first part of light is input into a feedback branch, feedback light is formed on the feedback branch, the feedback light is used for driving the multi-wavelength laser array (1) to enter a chaotic state, and the second part of light is output to the photoelectric detector (6) through the signal output end of the optical coupler (3) for optical mixing and terahertz noise generation.
3. The terahertz noise signal generating device based on multi-beam tunable chaotic light mixing according to claim 1, wherein the multi-wavelength laser array (1) is a monolithically integrated distributed feedback laser array, and an active region of each laser unit is provided with a grating structure with different periods.
4. The terahertz noise signal generating device based on multi-beam tunable chaotic light mixing according to claim 1, wherein the variable optical attenuator (4) is a controllable linear optical attenuation device and is used for regulating and controlling the feedback optical power intensity of a feedback branch to a chaotic state trigger threshold.
5. The terahertz noise signal generating device based on multi-beam tunable chaotic light mixing according to claim 2, wherein the polarization controller (5) is an adjustable polarization regulating device, and is used for regulating the polarization direction of the feedback light, changing the polarization direction of the feedback light and the polarization directions of n wavelength lasers output by the multi-wavelength laser array (1), and regulating the feedback intensity.
6. The terahertz noise signal generating device based on multi-beam tunable chaotic light mixing according to claim 1, wherein the photodetector (6) is a high-speed broadband type photodetector device, and frequency components overlapped with each other are generated in an electric domain by utilizing randomness of incoherent light in amplitude and phase through electro-optic conversion after light mixing to form a continuous broadband electric noise spectrum.
7. The terahertz noise signal generating device based on multi-beam tunable chaotic light mixing according to claim 1, further comprising a harmonic mixer (7) and a spectrometer (8), the spectrometer (8) being configured to provide a local oscillator signal to the harmonic mixer (7); The photoelectric detector (6) inputs a broadband terahertz signal to a radio frequency input end of the harmonic mixer (7), and the harmonic mixer (7) mixes the broadband terahertz electric signal with a local oscillation signal and converts the broadband terahertz signal into frequency; The spectrometer (8) performs continuous spectrum scanning on the frequency-converted broadband terahertz signal, displays information of the broadband terahertz signal in real time, and monitors the super-noise ratio.
8. The device for generating terahertz noise signal based on multi-beam tunable chaotic light mixing according to claim 7, wherein the information of the broadband terahertz signal comprises spectral amplitude and frequency distribution.
9. The terahertz noise signal generating device based on multi-beam tunable chaotic light mixing according to claim 7, wherein the harmonic mixer (7) down-converts a broadband terahertz signal to an intermediate frequency signal when the broadband terahertz signal is frequency-converted.
10. A terahertz noise signal generating system based on multi-beam tunable chaotic light mixing, which is characterized by comprising the terahertz noise signal generating device based on multi-beam tunable chaotic light mixing according to any one of claims 1 to 8.

Description

Terahertz noise signal generation device and system based on multi-beam tunable chaotic light mixing Technical Field The invention relates to the technical field of terahertz noise signal generation, in particular to a terahertz noise signal generation device and system based on multi-beam tunable chaotic light mixing. Background The terahertz noise source is used as a key basic tool for terahertz noise coefficient measurement and performance evaluation, and has important application prospects in the fields of remote sensing detection, communication transmission, military application and the like. The terahertz noise source is mainly realized by a thermal noise source, an electrical noise source and a radio frequency photonics noise source. At present, the prior art generally adopts a broadband incoherent light mixing mode to generate terahertz noise, but the mode has a plurality of defects, such as lower super-noise ratio, unsatisfactory frequency spectrum flatness of the generated terahertz noise signal, incapability of realizing flexible regulation and control of frequency component intensity and the like, and further limits the application of the terahertz noise signal in a scene requiring high dynamic range and high-precision frequency spectrum control. Disclosure of Invention In order to solve the problems of low ultra-noise ratio and insufficient regulation flexibility of the terahertz noise signals generated by the prior art, the invention provides a terahertz noise signal generation device and system based on multi-beam tunable chaotic light mixing, which realize flexible control of the intensity of each frequency component in the terahertz noise signals and generate the terahertz noise signals with flat frequency spectrum and adjustable signal-to-noise ratio. In order to achieve the technical effects, the technical scheme of the invention is as follows: A terahertz noise signal generating device based on multi-beam tunable chaotic light mixing comprises a multi-wavelength laser array, a circulator, an optical coupler, a variable optical attenuator, a polarization controller and a photoelectric detector; the multi-wavelength laser array is internally provided with a plurality of independent laser units, each laser unit and the adjacent laser units are preset with fixed wavelength intervals, each laser unit independently carries out working current adjustment, and the central wavelength of the laser unit is changed to change the frequency range of the terahertz noise spectrum; The first output end of the optical coupler is connected with the input end of the variable optical attenuator, the output end of the variable optical attenuator is connected with the input end of the polarization controller, and the output end of the polarization controller is connected with the third port of the circulator to form a feedback branch, on the feedback branch, the variable optical attenuator regulates and controls the power intensity of the n-wavelength laser to a chaotic state trigger threshold value, the polarization controller changes the polarization state of an initial laser signal, and the laser signal regulated and controlled by the variable optical attenuator and the polarization controller is directionally transmitted through the circulator and then is output from the first port and is input into a multi-wavelength laser array to form external optical feedback disturbance, so that the multi-wavelength laser array enters the chaotic state; the signal output end of the optical coupler is connected with the input end of the photoelectric detector to form a signal branch, and the photoelectric detector carries out electro-optic conversion on n bundles of chaotic lasers on the signal branch to output broadband terahertz signals through optical mixing. Preferably, the n wavelength lasers output from the second port of the circulator and entering the optical coupler are split into a first part of light and a second part of light according to a preset proportion through the first output end of the optical coupler, the first part of light is input to the feedback branch, feedback light is formed on the feedback branch, the feedback light is used for driving the multi-wavelength laser array to enter a chaotic state, and the second part of light is output to the photoelectric detector through the signal output end of the optical coupler and used for optical mixing and generating terahertz noise. Preferably, the multi-wavelength laser array is a monolithically integrated distributed feedback laser array, and the active region of each laser unit is provided with a grating structure having a different period. Preferably, the variable optical attenuator is a controllable linear optical attenuation device, and is used for regulating and controlling the feedback optical power intensity of the feedback branch to a chaotic trigger threshold. Preferably, the polarization controller is an adjustable polarization regulation