Apparatus and method for measuring angular vibration based on squeezed light source

Abstract

The present application relates to the technical field of laser quantum interference measurement, in particular to an angular vibration measurement device and method based on a squeezed state light source, which can measure high-frequency angular vibration parameters, and the measurement result is expected to break through the standard quantum limit, and effectively improve the measurement accuracy. The present application uses a continuous variable squeezed state quantum light source combined with linear interference measurement to propose a high-frequency angular vibration measurement device based on a squeezed state light source, which can measure high-frequency angular vibration parameters, and the measurement result is expected to break through the standard quantum limit, effectively improve the measurement accuracy, solve the problem that the measurement result cannot break through the standard quantum limit in the traditional interference measurement process, and thus realize high-sensitivity measurement.

Description

Technical Field

[0001] This invention relates to the field of laser quantum interference measurement technology, specifically to an angular vibration measurement device and method based on a compressed state light source. Background Technology

[0002] Current methods for measuring high-frequency angular vibration typically employ laser interferometry. This involves using a heterodyne laser interferometer in conjunction with a standard angular vibration table (capable of generating known angular vibration signals) to precisely measure high-frequency angular vibrations through laser interference. During measurement, a standard angular vibration table generates a high-frequency angular vibration signal with known frequency and amplitude, and then the laser interferometer measures the parameters of this signal. The laser used in the measurement is a coherent laser. A current limitation of this technique is that, in the field of high-precision measurement, the achieved accuracy is insufficient to meet measurement requirements, necessitating further improvements in measurement precision. Summary of the Invention

[0003] In view of this, the present invention provides an angular vibration measurement device and method based on a compressed state light source, which can measure high-frequency angular vibration parameters. The measurement results are expected to break through the standard quantum limit and effectively improve the measurement accuracy.

[0004] To achieve the above objectives, the technical solution of the present invention is as follows:

[0005] An angular vibration measurement device based on a compressed state light source includes a laser light source, a beam splitter prism, a continuous variable light source generation module, an MZ interference optical path, an optical fiber circulator, and a standard vibration exciter.

[0006] In this system, the same laser source generates coherent light and compressed light, with the continuous variable source generating module generating the compressed light. The coherent light and the compressed light are injected into the MZ interference optical path from both ends of the beam splitter. Using an optical fiber circulator, the measurement light carrying angular vibration information obtained by reflection is returned to the MZ interference optical path. The measurement light and the reference light are combined and interfered by the beam splitter for zero-beat balance detection. A standard vibration exciter is used to generate a standard mechanical vibration signal.

[0007] Specifically, it includes a laser source, a first beam splitter, a second reflector, a third reflector, a continuous variable source generation module, a second beam splitter, an acousto-optic frequency shifter, a fourth reflector, a fifth reflector, an optical fiber circulator, a first collimator, a second collimator, a third beam splitter, a first photodetector, a target mirror, a reference accelerometer, a standard vibration exciter, a second photodetector, a signal acquisition and processing device, a vibration controller, and a computer.

[0008] The coherent light generated by the laser source is split into two beams after passing through the first beam splitter. The transmitted laser beam is incident on the second reflector and, after reflection, reaches the second beam splitter. The reflected laser beam is incident on the third reflector and, after reflection, enters the continuous variable light source generation module to generate compressed light, which is also sent to the second beam splitter. The two laser beams are combined and split on the second beam splitter. After transmission and reflection by the second beam splitter, both the transmitted and reflected light contain coherent light and compressed light. One laser beam is frequency-shifted by an acousto-optic frequency shifter and reaches the fifth reflector. The other laser beam is incident on the fourth reflector and, after reflection, reaches the fiber optic circulator. The optical signal is input from port ① of the fiber optic circulator and output from port ② in digital order. The laser signal output from port ② passes through the first collimator and is incident on the target mirror. The target mirror is fixed on a standard vibration exciter, which generates a standard mechanical vibration signal under the control of a vibration controller, referencing the accelerometer and the target mirror. The mirror is fixedly mounted on the standard vibration exciter; the output signal of the reference accelerometer serves as the feedback signal for vibration control, and the output electrical signal is fed back to the vibration controller. The vibration controller receives the feedback signal from the reference accelerometer, performs calculations and solutions according to a preset algorithm, thereby achieving precise control of the standard mechanical vibration signal; after the laser is reflected by the target mirror, the laser light signal carrying angular vibration is incident on the optical fiber through the first collimator and transmitted to port ② of the optical fiber circulator, and output from port ③; the laser signal output from port ③ of the optical fiber circulator is collimated by the second collimator and reaches the third beam splitter, where it merges with the laser reflected by the fifth mirror in the third beam splitter. After being split by the third beam splitter, the beams reach the first photodetector and the second photodetector respectively; the first photodetector and the second photodetector convert the collected interference light signal into interference electrical signal, and the signal acquisition and processing device performs signal solution and processing on the interference electrical signal. The obtained angular vibration information is displayed and output by the computer.

[0009] The spatial optical path devices used are optical lenses or fiber optic devices.

[0010] The standard vibration exciter is a low-frequency standard exciter, a medium-frequency standard exciter, or a high-frequency standard exciter.

[0011] This invention also provides a three-degree-of-freedom angle measurement method based on radially polarized light, which uses the device described in this invention to perform the measurement and includes the following steps:

[0012] The laser source generates fundamental frequency light, which is split into two beams after passing through the first beam splitter. The transmitted coherent laser beam is incident on the second reflector and, after reflection, reaches the second beam splitter. The laser beam reflected by the first beam splitter is incident on the third reflector and, after reflection, is generated into a compressed laser beam by the continuous variable light source generation module, which then reaches the second beam splitter. After passing through the second beam splitter, the two laser beams undergo transmission and reflection, respectively, with both the transmitted and reflected light containing coherent and compressed laser beams. One laser beam is frequency-shifted by an acousto-optic frequency shifter and reaches the fifth reflector. The other laser beam is incident on the fourth reflector and, after reflection, reaches the fiber optic circulator. When the laser signal is input from port ① of the fiber optic circulator, it is output from port ② in digital order. The laser signal output from port ② passes through the first collimator and is incident on the target mirror. The target mirror is fixed on a standard vibration exciter, which generates a standard mechanical vibration signal under the control of a vibration controller. An accelerometer and a target mirror are fixedly mounted on a standard vibration exciter. The output signal of the reference accelerometer serves as the feedback signal for vibration control. The output electrical signal is fed back to the vibration controller. The vibration controller receives the feedback signal from the reference accelerometer and performs calculations and solutions according to a preset algorithm, thereby achieving control of the high-frequency standard mechanical vibration signal. After being reflected by the target mirror, the laser light signal carrying high-frequency angular vibration is incident on the optical fiber through the first collimator and transmitted to port ② of the optical fiber circulator, and output from port ③. The laser signal output from port ③ of the optical fiber circulator is collimated by the second collimator and reaches the third beam splitter. It merges with the laser light reflected by the fifth mirror in the third beam splitter. After being split by the third beam splitter, the beams reach the first photodetector and the second photodetector respectively. The first photodetector and the second photodetector convert the collected interference light signal into interference electrical signal. The signal acquisition and processing device then performs signal solution and processing on the interference electrical signal to obtain angular vibration information.

[0013] Beneficial effects:

[0014] 1. This invention utilizes a continuous variable squeezed state quantum light source combined with linear interferometry to propose a high-frequency angular vibration measurement device based on a squeezed state light source, which realizes the measurement of high-frequency angular vibration parameters. The measurement results are expected to break through the standard quantum limit, effectively improving the measurement accuracy and solving the problem that the measurement results in traditional interferometry cannot break through the standard quantum limit, thereby achieving high-sensitivity measurement.

[0015] 2. The advantages of this invention compared to existing technologies are as follows: Existing technologies typically use coherent lasers as the laser source for high-frequency angular vibration measurements. This invention uses a compressed laser source as the measurement source and injects it into the high-frequency angular vibration measurement device. This allows it to overcome the shot noise limit of classical measurements and achieve higher precision. Most existing technologies use spatial optical path devices to build the optical path for measurement. In this invention, all spatial optical path devices can be replaced by fiber optic devices, achieving all-fiber optic measurement. While ensuring the miniaturization of the measurement device, the measurement stability and reliability are further improved.

[0016] 3. The method of this invention is based on the device of this invention. It utilizes a continuous variable squeezed state quantum light source combined with linear interferometry to measure high-frequency angular vibration parameters. The measurement results are expected to break through the standard quantum limit, effectively improving the measurement accuracy and solving the problem that the measurement results in traditional interferometry cannot break through the standard quantum limit, thereby achieving high-sensitivity measurement. The method of this invention is based on the device of this invention. It uses a squeezed state light source as the measurement light source and injects the squeezed state light source into the high-frequency angular vibration measurement device. This can break through the shot noise limit of classical measurement in high-frequency angular vibration measurement and achieve higher precision measurement.

[0017] 4. In the device of the present invention, the standard vibration exciter can be replaced with a low-frequency and medium-frequency standard exciter, and the device of the present invention can be extended to be applicable to low-frequency and medium-frequency angular vibration measurement devices. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the angular vibration measurement device based on a compressed state light source according to the present invention. Detailed Implementation

[0019] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0020] Compressed light, as a non-classical optical field, can improve phase measurement accuracy by reducing the noise of a certain orthogonal component. Simultaneously, by redistributing the fluctuations of two conjugate observables, compressed light reduces the fluctuation of one of the observables, thereby improving measurement sensitivity. This invention provides a high-frequency angular vibration measurement device based on a compressed light source, the structure of which is as follows: Figure 1As shown, it includes: a laser source (1), a first beam splitter (2), a second reflector (3), a third reflector (4), a continuous variable source generation module (5), a second beam splitter (6), an acousto-optic frequency shifter (7), a fourth reflector (8), a fifth reflector (9), an optical fiber circulator (10), a first collimator (11), a second collimator (12), a third beam splitter (13), a first photodetector (14), a target mirror (15), a reference accelerometer (16), a standard vibration exciter (17), a second photodetector (18), a signal acquisition and processing device (19), a vibration controller (20), and a computer (21).

[0021] The fundamental frequency light (coherent laser) generated by the laser source (1) is split into two laser beams after passing through the first beam splitter (2). The transmitted laser beam is incident on the second reflector (3) and, after reflection, reaches the second beam splitter (6). The reflected laser beam is incident on the third reflector (4) and, after reflection, enters the continuous variable light source generation module (5) to generate a compressed laser beam (measurement light source). The generated compressed laser beam is also sent to the second beam splitter (6). The two laser beams are combined and split on the second beam splitter (6). After being transmitted and reflected by the second beam splitter (6), both the transmitted and reflected light beams contain coherent and compressed laser beams. One of the laser beams passes through an acousto-optic frequency shifter (7). After frequency shifting, the laser beam reaches the fifth reflector (9); another laser beam is incident on the fourth reflector (8), and after being reflected by the fourth reflector (8), it reaches the fiber optic circulator (10); the optical signal is input from port ① of the fiber optic circulator (10), and output from port ② in digital order. The laser signal output from port ② is incident on the target mirror (15) after passing through the first collimator (11); the target mirror (15) is fixed on the standard vibration exciter (17), and the standard vibration exciter (17) generates a high-frequency standard mechanical vibration signal under the control of the vibration controller (20). The reference accelerometer (16) and the target mirror (15) are fixedly installed on the standard vibration exciter (17). The output signal of the reference accelerometer (16) serves as the feedback signal for vibration control. The output electrical signal (charge or voltage) is amplified by a preamplifier and then fed back to the vibration controller (20). The vibration controller (20) receives the feedback signal from the reference accelerometer (16) and performs calculations and solutions according to a preset algorithm, thereby achieving precise control of the high-frequency standard mechanical vibration signal. After the laser is reflected by the target mirror (15), the laser light signal carrying the high-frequency angular vibration is incident into the optical fiber through the first collimator (11) and transmitted to port ② of the fiber optic circulator (10), and output from port ③. The output laser signal is collimated by the second collimator (12) and reaches the third beam splitter (13). It is then combined with the laser reflected by the fifth mirror (9) in the third beam splitter (13). After being split by the third beam splitter (13), the laser signals reach the first photodetector (14) and the second photodetector (18) respectively. The first photodetector (14) and the second photodetector (18) convert the collected interference light signals into electrical signals. The signal acquisition and processing device (19) performs signal calculation and processing on the interference electrical signals. The high-frequency angular vibration information (such as angular acceleration) obtained by the processing is displayed and output by the computer (20), thereby realizing high-precision vibration calibration on site.

[0022] In summary, the device of this invention utilizes a Mach-Zehnder (MZ) interference optical path structure to measure high-frequency angular vibrations. Specifically, it uses the same laser source to generate coherent light and compressed light, wherein the continuous variable source generation module generates compressed light using a conventional method. The coherent light and compressed light are injected into the MZ interference optical path from both ends of the beam splitter. Using an optical fiber circulator, the measurement light carrying angular vibration information obtained by reflection is returned to the MZ interference optical path. The measurement light and the reference light are combined and interfered by the beam splitter for zero-beat balance detection.

[0023] Furthermore, the standard vibration exciter (17) can be replaced with a low-frequency and medium-frequency standard exciter, and the device of the present invention is equally applicable, that is, the device of the present invention can be extended to be applicable to low-frequency and medium-frequency angular vibration measurement devices.

[0024] Furthermore, the first beam splitter (2), the second beam splitter (6), and the third beam splitter (13) can be replaced with fiber optic couplers, meaning that all spatial optical path devices in the device can be replaced by fiber optic devices to achieve all-fiber device measurement.

[0025] The present invention also provides a method for measuring angular vibration based on a compressed light source, implemented using the device of the present invention, comprising the following steps:

[0026] The laser source (1) generates fundamental frequency light, which is split into two laser beams after passing through a first beam splitter (2) with a certain beam splitting ratio. The transmitted coherent laser beam is incident on a second reflector (3) and, after reflection, reaches the second beam splitter (6). The laser beam reflected by the first beam splitter (2) is incident on a third reflector (4) and, after reflection, is generated by a continuous variable light source generation module (5) to produce a compressed laser beam, which then reaches the second beam splitter (6). After passing through the second beam splitter (6), the two laser beams are transmitted and reflected according to the beam splitting ratio. Both the transmitted and reflected light contain coherent and compressed laser beams. One laser beam is frequency-shifted by an acousto-optic frequency shifter (7) and reaches the fifth reflector (9). The other laser beam is incident on a fourth reflector (8) and, after reflection by the fourth reflector (08), reaches the fiber optic circulator (10). When the laser signal is input from port ① of the fiber optic circulator, it is output from port ② in digital order with very little loss. The laser signal output from port ② passes through the first collimator (11) and is incident on the target mirror (15). The target mirror (15) is fixed on the standard vibration exciter (17). The standard vibration exciter (17) generates a high-frequency standard mechanical vibration signal under the control of the vibration controller (20). The reference accelerometer (16) and the target mirror (15) are fixedly installed on the standard vibration exciter (17). The output signal of the reference accelerometer (16) serves as the feedback signal for vibration control. The output electrical signal (charge or voltage) is amplified by a preamplifier and then fed back to the vibration controller (20). The vibration controller (20) receives the feedback signal from the reference accelerometer (16) and performs calculations and solutions according to a preset algorithm, thereby achieving precise control of the high-frequency standard mechanical vibration signal. After the laser is reflected by the target mirror (15), the laser light signal carrying the high-frequency angular vibration is incident into the optical fiber through the first collimator (11) and transmitted to port ② of the fiber optic circulator (10), and output from port ③. The output laser signal is collimated by the second collimator (12) and reaches the third beam splitter (13). It is then combined with the laser reflected by the fifth mirror (9) in the third beam splitter (13). After being split by the third beam splitter (13), the laser signals reach the first photodetector (14) and the second photodetector (18) respectively. The first photodetector (14) and the second photodetector (18) convert the collected interference light signals into electrical signals. The signal acquisition and processing device (19) performs signal calculation and processing on the interference electrical signals. The high-frequency angular vibration information (such as angular acceleration) obtained after processing is displayed and output by the computer (20), thereby realizing high-precision angular vibration measurement.

[0027] In summary, the above are merely preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. An angular vibration measuring device based on a compressed state light source, characterized in that, It includes a laser source, a first beam splitter, a second reflector, a third reflector, a continuous variable light source generation module, a second beam splitter, an acousto-optic frequency shifter, a fourth reflector, a fifth reflector, an optical fiber circulator, a first collimator, a second collimator, a third beam splitter, a first photodetector, a target mirror, a reference accelerometer, a standard vibration exciter, a second photodetector, a signal acquisition and processing device, a vibration controller, and a computer; In this system, a single laser source generates coherent light and compressed light, with the compressed light generated by the continuous variable source module. The coherent light and the compressed light are injected into the MZ interference optical path from both ends of a beam splitter. Using a fiber optic circulator, the measurement light carrying angular vibration information obtained by reflection is returned to the MZ interference optical path. The measurement light and the reference light are combined and interfered by the beam splitter for zero-beat balance detection. A standard vibration exciter is used to generate a standard mechanical vibration signal. Specifically, the coherent light generated by the laser source is split into two laser beams after passing through the first beam splitter. The transmitted laser beam is incident on the second reflector and, after reflection, reaches the second beam splitter. The reflected laser beam is incident on the third reflector and, after reflection, enters the continuous variable light source generation module to generate compressed light, which is also sent to the second beam splitter. The two laser beams are combined and split on the second beam splitter. After transmission and reflection by the second beam splitter, both the transmitted and reflected light contain coherent light and compressed light. One laser beam is frequency-shifted by an acousto-optic frequency shifter and reaches the fifth reflector. The other laser beam is incident on the fourth reflector and, after reflection, reaches the fiber optic circulator. The optical signal is input from port ① of the fiber optic circulator and output from port ② in digital order. The laser signal output from port ② passes through the first collimator and is incident on the target mirror. The target mirror is fixed on a standard vibration exciter, which generates a standard mechanical vibration signal under the control of a vibration controller, referencing the accelerometer and the target mirror. The mirror is fixedly mounted on the standard vibration exciter; the output signal of the reference accelerometer serves as the feedback signal for vibration control, and the output electrical signal is fed back to the vibration controller. The vibration controller receives the feedback signal from the reference accelerometer, performs calculations and solutions according to a preset algorithm, thereby achieving precise control of the standard mechanical vibration signal; after the laser is reflected by the target mirror, the laser light signal carrying angular vibration is incident on the optical fiber through the first collimator and transmitted to port ② of the optical fiber circulator, and output from port ③; the laser signal output from port ③ of the optical fiber circulator is collimated by the second collimator and reaches the third beam splitter, where it merges with the laser reflected by the fifth mirror in the third beam splitter. After being split by the third beam splitter, the beams reach the first photodetector and the second photodetector respectively; the first photodetector and the second photodetector convert the collected interference light signal into interference electrical signal, and the signal acquisition and processing device performs signal solution and processing on the interference electrical signal. The obtained angular vibration information is displayed and output by the computer.

2. The apparatus as described in claim 1, characterized in that... The spatial optical path devices used are optical lenses or fiber optic devices.

3. The apparatus as described in claim 1, characterized in that... The standard vibration exciter is a low-frequency standard exciter, a medium-frequency standard exciter, or a high-frequency standard exciter.

4. A three-degree-of-freedom angle measurement method based on radially polarized light, characterized in that, The measurement is performed using the apparatus as described in claim 1, comprising the following steps: The laser source generates fundamental frequency light, which is split into two beams after passing through the first beam splitter. The transmitted coherent laser beam is incident on the second reflector and, after reflection, reaches the second beam splitter. The laser beam reflected by the first beam splitter is incident on the third reflector and, after reflection, is generated into a compressed laser beam by the continuous variable light source generation module, which then reaches the second beam splitter. After passing through the second beam splitter, the two laser beams undergo transmission and reflection, respectively, with both the transmitted and reflected light containing coherent and compressed laser beams. One laser beam is frequency-shifted by an acousto-optic frequency shifter and reaches the fifth reflector. The other laser beam is incident on the fourth reflector and, after reflection, reaches the fiber optic circulator. When the laser signal is input from port ① of the fiber optic circulator, it is output from port ② in digital order. The laser signal output from port ② passes through the first collimator and is incident on the target mirror. The target mirror is fixed on a standard vibration exciter, which generates a standard mechanical vibration signal under the control of a vibration controller. An accelerometer and a target mirror are fixedly mounted on a standard vibration exciter. The output signal of the reference accelerometer serves as the feedback signal for vibration control. The output electrical signal is fed back to the vibration controller. The vibration controller receives the feedback signal from the reference accelerometer and performs calculations and solutions according to a preset algorithm, thereby achieving control of the high-frequency standard mechanical vibration signal. After being reflected by the target mirror, the laser light signal carrying high-frequency angular vibration is incident on the optical fiber through the first collimator and transmitted to port ② of the optical fiber circulator, and output from port ③. The laser signal output from port ③ of the optical fiber circulator is collimated by the second collimator and reaches the third beam splitter. It merges with the laser light reflected by the fifth mirror in the third beam splitter. After being split by the third beam splitter, the beams reach the first photodetector and the second photodetector respectively. The first photodetector and the second photodetector convert the collected interference light signal into interference electrical signal. The signal acquisition and processing device then performs signal solution and processing on the interference electrical signal to obtain angular vibration information.

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