CN-116338637-B - Laser measurement system and method

CN116338637BCN 116338637 BCN116338637 BCN 116338637BCN-116338637-B

Abstract

The disclosure provides a laser measurement system and a laser measurement method, which are applied to the technical field of microwave photons. The system comprises an antenna, a microwave source, a laser, a polarization controller, a double parallel Mach-Zehnder modulator, an electric coupler, a photoelectric detector and a signal processing module. The antenna is used for receiving echo signals, the microwave source is used for sending out reference signals, the polarization controller is used for controlling the polarization direction of an optical carrier sent out by the laser, the echo signals and the reference signals are modulated onto the optical carrier with the controlled polarization direction through the double parallel Mach-Zehnder modulators and output modulated optical signals, the modulated optical signals enter the signal processing module after being subjected to beat frequency processing of the photoelectric detector, and the signal processing module outputs a final result so as to obtain Doppler frequency shift and arrival angle measurement results. The Doppler frequency shift and the arrival angle can be measured simultaneously, the direction of the Doppler frequency shift is judged, the Doppler frequency shift is not limited by electromagnetic interference and the working bandwidth, and the working bandwidth is extremely large.

Inventors

LI XINTONG
TAO JINMING
LI JINYE
LIU JIANGUO

Assignees

中国科学院半导体研究所

Dates

Publication Date: 20260508
Application Date: 20221212

Claims (6)

1. A laser measurement system, comprising: the device comprises a first antenna, a second antenna, a microwave source, a laser, a polarization controller, a double parallel Mach-Zehnder modulator, a photoelectric detector, a signal processing module and an electric coupler; The first antenna is used for receiving a first echo signal; The second antenna is used for receiving a second echo signal; the microwave source is used for sending out a reference signal; the electric coupler is used for combining the first echo signal and the reference signal to obtain a reference signal; the laser is used for emitting a first optical carrier wave; The polarization controller is used for controlling the polarization direction of the first optical carrier to obtain a second optical carrier; The dual-parallel Mach-Zehnder modulator comprises a branch beam splitter, a first sub Mach-Zehnder modulator, a second sub Mach-Zehnder modulator and a polarization beam combiner, wherein the branch beam splitter is used for equally dividing the second optical carrier into two beams according to the optical power of the second optical carrier to obtain a third optical carrier and a fourth optical carrier, the first sub Mach-Zehnder modulator is used for receiving the third optical carrier and the second echo signal to obtain a first pre-modulation optical signal, the second sub Mach-Zehnder modulator is used for receiving the fourth optical carrier and the return signal to obtain a second pre-modulation optical signal, and the polarization beam combiner is used for combining the first pre-modulation optical signal and the second pre-modulation optical signal to obtain a modulation optical signal; the photoelectric detector is used for performing beat frequency processing on the modulated optical signal and converting the modulated optical signal into an electric signal; the signal processing module is used for receiving the electric signals and calculating to obtain measurement results of Doppler frequency shift and arrival angle.
2. The laser measurement system of claim 1, wherein the first sub-mach-zehnder modulator and the second sub-mach-zehnder modulator are both of the push-pull mach-zehnder modulator type; The first sub Mach-Zehnder modulator and the second sub Mach-Zehnder modulator are in parallel connection structure; The first sub Mach-Zehnder modulator and the second sub Mach-Zehnder modulator each have a radio frequency input port and a DC offset port.
3. The laser measurement system of claim 1, wherein the dual parallel mach-zehnder modulator further comprises a main dc bias port; the main DC bias port is used for adjusting the phase between the first pre-modulation optical signal and the second pre-modulation optical signal.
4. The laser measurement system of claim 1, wherein the type of branching beam splitter is a 3dB Y-branching beam splitter.
5. The laser measurement system of claim 1, wherein the first optical carrier is continuously linearly polarized light.
6. A laser measurement method, characterized in that it is applied to the laser measurement system according to any one of claims 1 to 5, the method comprising: receiving a preset echo signal by using an antenna; A microwave source is utilized to send out a reference signal; Emitting a first optical carrier wave by using a laser; controlling the polarization direction of the first optical carrier by using a polarization controller to obtain a second optical carrier; Modulating the preset echo signal and the reference signal onto the second optical carrier by using a double parallel Mach-Zehnder modulator to obtain a modulated optical signal; Performing beat frequency processing on the modulated optical signal by using a photoelectric detector, and converting the modulated optical signal into an electric signal; and receiving the electric signals by using a signal processing module, and calculating to obtain the measurement results of Doppler frequency shift and arrival angle.

Description

Laser measurement system and method Technical Field The disclosure relates to the technical field of microwave photons, in particular to a laser measurement system and a laser measurement method. Background In radar ranging, intelligent driving, wireless communication and other emerging fields, it is important to obtain the position and speed of a moving object. The doppler shift is the frequency of the received echo signal subtracted from the frequency of the transmitted signal from the radar, carrying the speed and direction parameters of the moving object. Measuring the angle of arrival of the echo signals can accurately discern the orientation of the object under test. Therefore, in practical application, the position, direction and travelling speed of the moving object can be accurately judged by using Doppler frequency shift and arrival angle. Conventional measurement methods are generally based on electrical systems, but are difficult to implement when the frequency to be measured is in the megahertz to sub-terahertz range due to the constraint of electronic bottlenecks such as narrow measurement bandwidth, weak anti-interference capability, large transmission loss, high measurement cost, low measurement sensitivity, and the like. In recent years, with the development and rising of microwave photonics, researchers begin to consider the measurement of Doppler shift and arrival angle by using the microwave photonics technology because the microwave photonics technology has the advantages of strong electromagnetic interference resistance, large bandwidth, low loss, high sensitivity, high stability, small volume, low cost and the like. However, the existing technical solution can only realize the measurement of the doppler shift or the arrival angle alone, but cannot realize the simultaneous measurement of the doppler shift and the arrival angle. Disclosure of Invention In view of the above, the present disclosure provides a laser measurement system and method to solve the problems that the working bandwidth is narrow and the doppler shift and the arrival angle cannot be measured simultaneously in the prior art. A first aspect of the present disclosure provides a laser measurement system comprising: the system comprises an antenna, a microwave source, a laser, a polarization controller, a double parallel Mach-Zehnder modulator, a photoelectric detector and a signal processing module; the antenna is used for receiving preset echo signals; the microwave source is used for sending out a reference signal; the laser is used for emitting a first optical carrier wave; The polarization controller is used for controlling the polarization direction of the first optical carrier to obtain a second optical carrier; the double parallel Mach-Zehnder modulator is configured to modulate the preset echo signal and the reference signal onto the second optical carrier to obtain a modulated optical signal; the photoelectric detector is used for performing beat frequency processing on the modulated optical signal and converting the modulated optical signal into an electric signal; the signal processing module is used for receiving the electric signals and calculating to obtain measurement results of Doppler frequency shift and arrival angle. According to an embodiment of the disclosure, the preset echo signal includes a first echo signal and a second echo signal, and the antenna includes: A first antenna and a second antenna; The first antenna is used for receiving the first echo signal; the second antenna is configured to receive the second echo signal. According to an embodiment of the disclosure, the measurement system further comprises an electrical coupler for combining the first echo signal and the reference signal to obtain a reference signal. According to an embodiment of the present disclosure, the dual parallel mach-zehnder modulator includes: A branch beam splitter, a first sub Mach-Zehnder modulator, a second sub Mach-Zehnder modulator and a polarization beam combiner; the branch beam splitter equally divides the second optical carrier into two beams according to the optical power of the second optical carrier, so as to obtain a third optical carrier and a fourth optical carrier; the first sub Mach-Zehnder modulator is configured to receive the third optical carrier and the second echo signal, and obtain a first pre-modulated optical signal; the second sub-Mach-Zehnder modulator is configured to receive the fourth optical carrier and the reference back signal, and obtain a second pre-modulated optical signal; The polarization beam combiner is configured to combine the first pre-modulated optical signal and the second pre-modulated optical signal to obtain a modulated optical signal. According to an embodiment of the present disclosure, the types of the first sub-mach-zehnder modulator and the second sub-mach-zehnder modulator are both push-pull mach-zehnder modulators; The first sub Mach-Zehnder modulator and the