Optical phase detection system based on quantum weak value amplification

Abstract

The invention relates to an optical phase detection system based on quantum weak value amplification, which comprises a front selection light polarization unit, a phase compensator, a sample coupling unit, a rear selection light polarization unit and a spectrograph which are sequentially positioned in the same light path, and the processor adjusts the introduced phase quantity of the phase compensator by controlling the servo motor. According to the system, the optical phase of the to-be-measured sample is calculated by calculating the sum of the phase of the sample light in the weak value amplification linear region and the phase of the phase compensator, so that the anti-noise capability of measurement is improved, and the problem of inaccurate measurement result caused by human interference of the sample light is effectively avoided; a weak value amplification linear region can be quickly adjusted through the average wavelength change trend, the light intensity change trend and the average wavelength-phase difference data set, and the problem that a large amount of time and energy need to be spent in searching for a proper measurement point when the optical phase of a sample is measured based on the weak value amplification technology in the prior art is solved.

Description

Technical Field

[0001] The invention relates to the technical field of quantum optics applications, and in particular to an optical phase detection system based on quantum weak value amplification. Background Art

[0002] Optical phase detection is a high-precision measurement technology that obtains information such as the three-dimensional morphology, refractive index distribution, and physical parameters of the measured object by measuring the phase change of light waves. It is widely used in many scientific research and engineering application fields. For example, in the biomedical field, optical phase detection can be used to measure parameters such as cell morphology, dry mass, and density; in the field of ultrafast laser processing, optical phase detection technology can detect the size of the processing cavity inside the transparent medium material and the regional morphology of the refractive index change around the processing area; in the field of materials science, optical phase detection technology can be used for anisotropic material property analysis, micro / nanostructure measurement, nonlinear optical performance testing, etc.; in the field of sensing, optical phase detection can better monitor changes in physical quantities such as pressure, liquid concentration, and temperature.

[0003] Existing optical phase detection technologies include phase difference wavefront detection technology and quantitative phase microscopy technology. Phase difference wavefront detection technology directly uses the intensity information of two or more images to reconstruct wavefront phase information and a clear image of the target. It has the advantages of simple optical path and low cost, but it is greatly affected by image noise, especially when observing dim targets, the detection accuracy is low. Quantitative phase microscopy technology uses interference patterns to extract phase information, which can achieve high-sensitivity and high-precision material structure measurement, but it has high requirements for experimental conditions and is greatly affected by the surface reflectivity of the object being measured, especially when the surface reflectivity of the object being measured is uneven, the detection accuracy is not ideal.

[0004] With the continuous development of modern science and technology, quantum weak value amplification technology has attracted great attention in the field of precision measurement due to its advantages of high accuracy, good robustness and low cost, and has become a measurement method of existing optical phase.

[0005] On the one hand, the effective range of the weak value amplification effect is very limited and is easily affected by human interference, resulting in inaccurate measurement results, which seriously limits its application scenarios. On the other hand, when optical phase measurement uses spectral detection, the slow spectral scanning speed and the inherent small effective range of weak value amplification technology, and the amplification effect is inversely proportional to the effective range, lead to the need to spend a lot of time and energy to find suitable measurement points in practical applications. Summary of the invention

[0006] Based on this, the object of the present invention is to provide an optical phase detection system based on quantum weak value amplification, and the detection method can realize fast and high-precision measurement of optical phase.

[0007] The technical solution adopted by the present invention is as follows.

[0008] An optical phase detection system based on quantum weak value amplification comprises: a light emitting unit, a front-selective light polarization unit, a phase compensator, a sample coupling unit, a rear-selective light polarization unit, a spectrometer, and a processor, which are sequentially in the same optical path; wherein the phase compensator controls the introduction of a phase quantity through a servo motor electrically connected thereto, the angle between the light transmission axis of the front-selective light polarization unit and the horizontal positive direction is +(π / 4) rad, the angle between the light transmission axis of the rear-selective light polarization unit and the horizontal positive direction is -(π / 4) rad, the processor is electrically connected and / or communicationally connected to the servo motor and the spectrometer, and the processor obtains the optical phase of the sample to be measured by the following method:

[0009] S1: Obtain the initial position of the servo motor at the initial moment, and obtain the initial spectrum of the spectrometer at the initial moment; determine whether there are double peaks in the initial spectrum:

[0010] If yes, execute step S2;

[0011] If no, execute step S3;

[0012] S2: Control the spectrometer to scan the spectrum of the sample to be tested and obtain the spectrum data at the current moment; calculate the average wavelength at the current moment based on the spectrum data at the current moment; obtain the slope of the corresponding segmented weak value amplification linear region of the average wavelength at the current moment in the average wavelength-phase difference data set, the average wavelength at the origin, and the initial position and current position of the servo motor to calculate the optical phase of the sample to be tested

[0013]

[0014] Where: b t represents the current position of the servo motor, b0 represents the initial position of the servo motor, d represents the phase amount introduced by the phase compensator corresponding to the minimum rotation interval of the servo motor, and λ t Indicates the average wavelength calculated from the current spectral data, λ i Represents λ t The average wavelength of the origin corresponding to the segmented weak value amplification linear region, K i Represents λ t The slope corresponding to the linear region of the segmented weak value amplification;

[0015] S3: Control the servo motor to rotate a data collection step rotation interval, according to the wavelength change trend and light intensity change trend of the average wavelength and total light intensity before and after the rotation, combined with the average wavelength-phase difference data set, control the servo motor to rotate clockwise or counterclockwise for a number of data collection step rotation intervals until double peaks appear in the spectrum graph, and execute step S2.

[0016] Furthermore, the slope K and the origin average wavelength λ corresponding to the segmented weak value amplification linear region used in step S2 are the preferred slope K of the preferred segment weak value amplification linear region in the weak value amplification linear region. O-i and the optimal origin average wavelength λ O-i .

[0017] Furthermore, the preferred segmented weak value amplification linear region is a linear region corresponding to the maximum absolute value of the slope of each segmented weak value amplification linear region of the weak value amplification linear region.

[0018] Furthermore, the optimal slope K of the linear region is enlarged by using the optimal segment weak value O-i and the optimal origin average wavelength λ O-i Calculate the optical phase of the sample to be measured Step S2 includes the following sub-steps:

[0019] S21: Control the spectrometer to scan the spectrum of the sample to be tested to obtain the spectrum data at the current moment; calculate the average wavelength and total light intensity according to the spectrum data at the current moment;

[0020] S22: judging whether the phase difference between the horizontal polarization component and the vertical polarization component of the sample light at the current moment is in the preferred weak value amplification linear region according to the average wavelength and the total light intensity:

[0021] If yes, execute step S23;

[0022] If no, execute step S24;

[0023] S23: Obtain the preferred slope of the preferred segment weak value amplification linear region corresponding to the average wavelength and the preferred origin average wavelength, and calculate the optical phase of the sample to be tested according to the average wavelength, the preferred slope, the preferred origin average wavelength, the initial position and the current position of the servo motor. satisfy:

[0024]

[0025] Where: b t represents the current position of the servo motor, b0 represents the initial position of the servo motor, d represents the phase amount introduced by the phase compensator corresponding to the minimum rotation interval of the servo motor, and λ t Indicates the average wavelength calculated from the current spectral data, λ O-i Represents λ t The average wavelength of the optimal origin corresponding to the weak value amplification linear region of the optimal segment, K O-i Represents λ t The preferred slope corresponding to the weak value amplification linear region of the preferred segment;

[0026] S24: Obtain the average wavelength of the origin of the weak value amplification linear region of the preferred segment of the cycle, and calculate the wavelength deviation between the average wavelength of the origin and the average wavelength; control the servo motor to rotate clockwise or counterclockwise by a number of data acquisition step rotation intervals according to the wavelength deviation, and execute step S21.

[0027] Furthermore, the preferred slope K corresponding to the linear region of the preferred segment weak value amplification adopted in step S22 is O-i and the optimal origin average wavelength λ O-i is the corrected preferred correction slope K CO-i and the optimal correction origin average wavelength λ CO-i , the optical phase of the sample to be measured satisfy:

[0028]

[0029] Where: CO-i Represents λ t The average wavelength of the optimal correction origin corresponding to the weak value amplification linear region of the optimal segment, K CO-i Represents λ t The preferred correction slope corresponding to the weak value amplification linear region of the preferred segment.

[0030] Furthermore, the preferred correction slope K CO-i and the optimal correction origin average wavelength λ CO-i Obtained by the following method:

[0031] SC1`: without placing the sample to be tested, after making the spectral data located in the preferred weak value amplification linear region according to the wavelength-phase relationship of the average wavelength-phase difference data set, the servo motor is controlled to rotate counterclockwise or clockwise by m calibration step rotation intervals, and the spectrometer is controlled to perform N scans, m ≥ 2, N ≥ 3;

[0032] SC2': Calculate the average wavelength of the spectrum data scanned each time in step SC1', and take the average value of N average wavelengths as the average wavelength corresponding to each calibration step rotation interval;

[0033] SC3`: Control the servo motor to rotate clockwise or counterclockwise by 1 calibration step rotation interval, the rotation direction is opposite to the rotation direction of step SC1, and control the spectrometer to scan N times, N ≥ 3;

[0034] SC4': Calculate the average wavelength of the spectrum data scanned each time in step SC3', and take the average value of the N average wavelengths as the average wavelength corresponding to each calibration step rotation interval;

[0035] SC5': Repeat steps SC3' and SC4' L times, generate a linear curve based on the average wavelength and phase difference of L+1 times and calculate the slope, and use the slope as the preferred correction slope K of the weak value amplification linear region of the preferred segment CO-i When L is an even number, the average wavelength of the L / 2+1th time is taken as the preferred correction origin average wavelength λ of the preferred weak value amplification linear region. CO-i When L is an odd number, the average wavelength of the (L+1) / 2th order is taken as the average wavelength of the optimal correction origin in the weak value amplification linear region of the optimal segment λ CO-i , where L≥4.

[0036] Furthermore, the slope K corresponding to the linear region of the segmented weak value amplification used in step S2 is i and the average wavelength λ at the origin i is the corrected slope K C-i and the average wavelength λ of the corrected origin C-i , the optical phase of the sample to be measured satisfy:

[0037]

[0038] Where: CO-i Represents λ t The average wavelength of the corrected origin corresponding to the linear region of the segmented weak value amplification, K CO-i Represents λ t The correction slope corresponding to the linear region of the segmented weak value amplification.

[0039] Furthermore, the correction slope K C-i and the average wavelength λ of the corrected origin C-i Obtained by the following method:

[0040] SC1: No sample is placed. According to the wavelength-phase relationship of the average wavelength-phase difference data set, the spectral data is located in the segmented weak value amplification linear region corresponding to the average wavelength at the current moment. The servo motor is controlled to rotate counterclockwise or clockwise by m calibration step rotation intervals, and the spectrometer is controlled to perform N scans, m ≥ 2, N ≥ 3;

[0041] SC2: Calculate the average wavelength of the spectrum data scanned each time in step SC1, and use the average value of N average wavelengths as the average wavelength corresponding to each calibration step rotation interval;

[0042] SC3: Control the servo motor to rotate clockwise or counterclockwise by 1 calibration step rotation interval, the rotation direction is opposite to the rotation direction of step SC1`, and control the spectrometer to scan N times, N ≥ 3;

[0043] SC4: Calculate the average wavelength of the spectrum data scanned each time in step SC3, and use the average value of N average wavelengths as the average wavelength corresponding to each calibration step rotation interval;

[0044] SC5: Repeat steps SC3 and SC4 L times, generate a linear curve based on the average wavelength and phase difference of L+1 times and calculate the slope, and use the slope as the correction slope K of the linear region of the segmented weak value amplification C-i When L is an even number, the average wavelength of the L / 2+1th time is taken as the average wavelength λ of the correction origin of the segmented weak value amplification linear region C-i When L is an odd number, the average wavelength of the (L+1) / 2th time is taken as the average wavelength λ of the correction origin of the segmented weak value amplification linear region C-i , where L≥4.

[0045] Furthermore, the average wavelength-phase difference data set is constructed by the following method:

[0046] SA1: Without placing the sample to be tested, control the servo motor to rotate counterclockwise or clockwise to the limit of the set total rotation range;

[0047] SA2: Control the servo motor to rotate clockwise or counterclockwise by 1 data acquisition step rotation interval, the rotation direction is opposite to the rotation direction of step SA1, and control the spectrometer to scan N times, N ≥ 3;

[0048] SA3: Calculate the average wavelength of the spectrum data scanned each time in step SA2, and use the average value of N average wavelengths as the average wavelength corresponding to each data acquisition step rotation interval;

[0049] SA4: Repeat steps SA2 and SA3 until the servo motor rotates to the set total rotation range, and draw an average wavelength-phase difference graph according to the phase difference and average wavelength corresponding to each data collection step rotation interval;

[0050] SA5: Calculate the slopes of each segmented weak value amplification linear region K1, K2, ..., K i ,...,K n ;

[0051] SA6: Calculate the data acquisition step rotation interval M corresponding to each segmented linear region. When M is an even number, the average wavelength of the M / 2+1th time is used as the average wavelength of the origin of the segmented weak value amplification linear region. When M is an odd number, the average wavelength of the (M+1) / 2th time is used as the average wavelength of the origin of the segmented weak value amplification linear region.

[0052] Compared with the prior art, the optical phase detection system of the present invention has the following beneficial effects:

[0053] 1) Based on quantum weak value amplification technology, the present invention focuses on the phase change between the horizontal polarization component and the vertical polarization component of the sample light caused by the sample to be measured itself, and calculates the optical phase of the sample to be measured by calculating the phase of the sample light in the weak value amplification linear region and the phase of the phase compensator, thereby improving the anti-noise ability of the measurement and effectively avoiding the problem of inaccurate measurement results caused by the interference of the sample light by the external environment;

[0054] 2) The present invention controls the rotation of the servo motor to obtain the average wavelength change trend and light intensity change trend before and after the rotation, and can quickly determine the phase supplement amount to be introduced by combining the data set, and quickly adjust the phase compensator to place the sample light in the double peak area, and based on the slope of the weak value amplification linear area in the double peak area and the average wavelength of the origin, quickly obtain the optical phase of the sample, and achieve high-precision phase measurement over a wide range, solving the problem that a lot of time and energy is required to find a suitable measurement point when measuring the optical phase of the sample based on the existing weak value amplification technology;

[0055] 3) The present invention uses a servo motor to control the phase compensator and uses a computer to control the entire measurement process, which is easy to operate and has a simple structure.

[0056] For better understanding and implementation, the present invention is described in detail below with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0057] Figure 1 A schematic diagram of a unit structure of an optical phase detection system according to an embodiment of the present invention;

[0058] Figure 2 a phase difference variation diagram between horizontal and vertical polarization components of the post-selected light and the average wavelength of the post-selected light;

[0059] Figure 3 It is a schematic diagram of the process of measuring the optical phase of a sample to be measured according to the present invention;

[0060] Figure 4 Figure 4 a and Figure 4 b is an example of a double peak spectrum corresponding to the post-selected light;

[0061] Figure 5 for Figure 3 Schematic diagram of the sub-step flow chart of step S2. DETAILED DESCRIPTION

[0062] The technical solution of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present invention.

[0063] In order to solve the problems that the existing optical phase detection system based on quantum weak value amplification is susceptible to human interference and leads to inaccurate measurement results; and the use of a spectrometer requires a lot of time and effort to adjust step by step so that the detection point is in the weak value linear amplification region, resulting in low efficiency, the present application proposes an optical phase detection system based on quantum weak value amplification. The system sets the transmission axis of the front selective light polarization unit to be at an angle of +(π / 4) rad with the horizontal positive direction, and sets the transmission axis of the rear selective light polarization unit to be at an angle of -(π / 4) rad with the horizontal positive direction. Based on the phase difference change between the horizontal polarization component and the vertical polarization component of the sample light caused by the sample to be tested itself, the sample light is adjusted in the weak value amplification linear region and further adjusted to the preferred weak value amplification linear segment, and the phase of the sample light in the weak value amplification linear region or in the preferred weak value amplification linear segment and the adjusted phase of the phase compensator are calculated to calculate the optical phase of the sample to be tested, thereby improving the anti-noise ability of the measurement and effectively avoiding the problem of inaccurate measurement results caused by human interference of the sample light. At the same time, by analyzing the change trend of the average wavelength and total light intensity of the sample light of the sample to be tested after being adjusted by the phase compensator, and adjusting the phase compensator in combination with the average wavelength-phase difference data set, the phase difference between the horizontal and vertical polarization components of the sample light is quickly modulated to the weak value amplification linear region, and then the optical phase of the sample is solved according to the adjustment amount of the phase compensator, the slope of the weak value amplification linear region and the average wavelength of the origin.

[0064] See also Figure 1 The optical phase detection system based on quantum weak value amplification of the present invention includes a light emitting unit 10, a front selective light polarization unit 20, a phase compensator 30, a sample coupling unit 40, a rear selective light polarization unit 50, a spectrometer 60, and a servo motor 70 electrically connected to the phase compensator 30, and a processor 80 electrically and / or communicatively connected to the spectrometer 60 and the servo motor 70.

[0065] During detection, the light emitting unit 10 emits a light beam, which is polarized into front-selective light by the front-selective light polarization unit 20. The front-selective light is adjusted to detection incident light by the phase compensator 30. After the detection incident light is coupled with the information of the sample to be tested in the sample coupling unit 40, it is polarized into sample light by the rear-selective light polarization unit 50. The sample light is received by the spectrometer 60 and converted into spectral data for transmission to the processor 80 for analysis.

[0066] Specifically, the light emitting unit 10 is a wide spectrum light source, and the light beam emission direction is adjusted to be horizontal to ensure that the light spot is small and does not diverge. A light emitting diode (LED) with a certain bandwidth, or a near-infrared super luminescent diode (SLD), or a C&L segment high-power white light source is used as a wide spectrum light source.

[0067] The front-selective light polarization unit 20 comprises a first polarizer 21 and a polarization state selector 22 which are sequentially arranged on the optical path. The front-selective light polarization unit 20 polarizes the light beam into front-selective light.

[0068] The transmission axis direction of the first polarizer 21 is adjusted so that the output polarized light direction is perpendicular to the polarized light direction output by the post-selective light polarization unit 50. Specifically, the transmission axis of the first polarizer 21 is at an angle of +(π / 4) rad to the horizontal positive direction, and the transmission axis of the post-selective light polarization unit 50 is at an angle of -(π / 4) rad to the horizontal positive direction. The first polarizer 21 is a thin film polarizer, a wire grid polarizer, an elliptical polarizer, etc.

[0069] The transmission axis direction of the polarization state selector 22 is consistent with the transmission axis direction of the first polarizer 21, but there is an angle ε between the two, ε is the system pre-selection angle. Specifically, the angle between the transmission axis direction of the polarization state selector 22 and the horizontal positive direction is set to +(π / 4+ε)rad. The polarization state selector 22 is a quarter wave plate, or a phase compensator with a compensation phase of ±(π / 2)rad.

[0070] The phase compensator 30 introduces a phase difference to the incident front selection light. The light transmission axis direction of the phase compensator 30 is consistent with the horizontal direction, and it performs phase compensation on the incident front selection light and adjusts it to detect the incident light. The phase compensator 30 is a Soret-Babinet compensator or a liquid crystal variable phase retarder.

[0071] In this embodiment, the phase compensator 30 is an optical element that can continuously adjust the phase. The compensation phase is adjusted by adjusting the micrometer of the phase compensator. The micrometer is electrically connected to the servo motor 70, and the servo motor 70 completes the corresponding adjustment operation according to the instructions issued by the processor 80.

[0072] The sample coupling unit 40 is a two-dimensional slide stage. The two-dimensional slide stage can move along the X-axis and the Y-axis, and can adjust the movement of the sample to be tested on the XOY plane, and the XOY plane is perpendicular to the optical path. The sample to be tested is fixed on the stage of the two-dimensional slide stage, and the optical phase information of the sample to be tested can be coupled.

[0073] The post-selective light polarization unit 50 is a second polarizer 51. The light transmission axis direction of the second polarizer 51 is adjusted so that the output polarized light direction is perpendicular to the polarized light direction output by the pre-selective light polarization unit 20. Specifically, the angle between the light transmission axis of the second polarizer 51 and the horizontal positive direction is -(π / 4) rad. The second polarizer 51 is a thin film polarizer, a wire grid polarizer, an elliptical polarizer, etc. The second polarizer 51 polarizes the light coupled with the sample signal into sample light, which is then received after being scanned by the spectrometer 60.

[0074] The servo motor 70 adjusts the phase compensator 30 according to the driving control signal sent by the processor 80 to achieve phase compensation adjustment of the front selection light.

[0075] The processor 80 receives the spectral data collected by the spectrometer 60, generates a feedback signal by calculating the average wavelength of the spectral data, and combines the preset data set to determine the rotation amount of the servo motor 70 of the phase compensator 30 and control the rotation of the servo motor 70 to adjust the phase amount introduced by the phase compensator 30, so that the phase difference between the horizontal and vertical polarization components of the sample light is in the weak value amplification linear region. When the phase difference between the horizontal and vertical polarization components of the sample light is in the weak value amplification linear region, the processor 80 controls the spectrometer 60 again to perform spectral scanning, obtains the new spectral data corresponding to the phase difference between the horizontal and vertical polarization components of the sample light in the weak value amplification linear region, and calculates the new average wavelength based on the new spectral data, and uses the new average wavelength, the rotation amount of the servo motor 70, the slope of the weak value amplification linear region, and the average wavelength of the origin of the weak value amplification linear region to calculate the optical phase of the sample to be tested.

[0076] Based on the setting of the above optical phase detection system, the processor also includes constructing an average wavelength-phase difference data set and correcting weak value amplification linear region data before measuring the optical phase of the sample to be measured.

[0077] (I) Constructing the average wavelength-phase difference data set

[0078] SA1: Without placing the sample to be tested, control the servo motor to rotate counterclockwise or clockwise to the set total rotation range boundary.

[0079] SA2: Control the servo motor to rotate clockwise or counterclockwise by 1 data acquisition step rotation interval, the rotation direction is opposite to the rotation direction of step SA1, and control the spectrometer to scan N times, N ≥ 3.

[0080] The data acquisition step rotation interval is set according to actual needs.

[0081] SA3: Calculate the average wavelength of the spectrum data scanned each time in step SA2, and use the average value of N average wavelengths as the average wavelength corresponding to each data acquisition step rotation interval.

[0082] SA4: Repeat steps SA2 and SA3 until the servo motor rotates to the set total rotation range, and draw an average wavelength-phase difference graph based on the phase difference and average wavelength corresponding to each data collection step rotation interval.

[0083] SA5: Calculate the slopes of each segmented weak value amplification linear region K1, K2, ..., K i ,...,K n.

[0084] K i It represents the slope of the i-th segmented weak value amplification linear region in the weak value amplification linear region within one cycle.

[0085] Furthermore, the best linear segment and the largest absolute slope value are selected from each segmented weak value amplification linear region as the preferred segmented weak value amplification linear region, such as |K i |=K MAX , then the slope is K i The linear region is taken as the preferred segment and the weak value amplifies the linear region.

[0086] SA6: Calculate the data acquisition step rotation interval M corresponding to each segmented linear region. When M is an even number, the average wavelength of the M / 2+1th time is used as the average wavelength of the origin of the segmented weak value amplification linear region. When M is an odd number, the average wavelength of the (M+1) / 2th time is used as the average wavelength of the origin of the segmented weak value amplification linear region.

[0087] If the slope is K i The linear region is the preferred weak value amplification linear region, and the data acquisition step rotation interval M corresponding to the preferred weak value amplification linear region i , when M i When it is an even number, the Mth i / 2+1 times the average wavelength as the preferred origin average wavelength λ of the weak value amplification linear region of the preferred section O-i , when M i When it is an odd number, the first (M i +1) / 2 times as the average wavelength of the optimal origin of the weak value amplification linear region λ O-i .

[0088] If the slope is K i The linear region is a non-optimal segment weak value amplification linear region. The data acquisition step rotation interval M corresponding to the segment weak value amplification linear region i , when M i When it is an even number, the Mth i / 2+1 times the average wavelength as the origin average wavelength λ of the weak value amplification linear region of the preferred section i , when M i When it is an odd number, the first (M i +1) / 2 times as the average wavelength of the origin of the weak value amplification linear region of the preferred section i .

[0089] See also Figure 2 , Figure 2 is the average wavelength-phase difference diagram, Figure 2 The large dashed box represents the linear region of weak value amplification within the period, and the small dashed box represents the linear region of weak value amplification in the preferred segment.

[0090] (II) Correction of weak value amplification linear region data

[0091] Since the system has optical drift after a period of time, in order to overcome the optical drift and to obtain more accurate slope of the weak value amplification linear region and average wavelength of the origin, it is also necessary to calibrate and update the slope of the weak value amplification linear region and the average wavelength of the origin in the above average wavelength-phase difference data set. The specific correction method is as follows.

[0092] SC1: Without placing the sample to be tested, the spectral data is located in the corresponding segmented weak value amplification linear region according to the wavelength-phase relationship of the average wavelength-phase difference data set, the servo motor is controlled to rotate counterclockwise or clockwise for m calibration step rotation intervals, and the spectrometer is controlled to perform N scans, m ≥ 2, N ≥ 3.

[0093] The calibration step rotation interval is set according to actual needs, and the calibration step rotation interval is usually set smaller than the data acquisition step rotation interval.

[0094] SC2: Calculate the average wavelength of the spectrum data scanned each time in step SC1, and use the average value of N average wavelengths as the average wavelength corresponding to each calibration step rotation interval.

[0095] SC3: Control the servo motor to rotate clockwise or counterclockwise by 1 calibration step rotation interval, and the rotation direction is opposite to the rotation direction of step SC1, and control the spectrometer to perform N scans, N ≥ 3.

[0096] SC4: Calculate the average wavelength of the spectrum data scanned each time in step SC3, and use the average value of the N average wavelengths as the average wavelength corresponding to each calibration step rotation interval.

[0097] SC5: Repeat steps SC3 and SC4 L times, generate a linear curve based on the average wavelength and phase difference of L+1 times and calculate the slope, and use the slope as the correction slope K of the linear region of the segmented weak value amplification C-i When L is an even number, the average wavelength of the L / 2+1th time is taken as the average wavelength λ of the correction origin of the segmented weak value amplification linear region C-i When L is an odd number, the average wavelength of the (L+1) / 2th time is taken as the average wavelength λ of the correction origin of the segmented weak value amplification linear region C-i , where L≥4.

[0098] The above correction method for the slope of each segmented weak value amplification linear region and the average wavelength of the origin in the weak value amplification linear region within the period is applicable to the correction of the slope and the average wavelength of the origin in the preferred segment weak value amplification linear region, as follows:

[0099] SC1ˋ: No sample is placed. After the spectral data is located in the optimal weak value amplification linear region according to the wavelength-phase relationship of the average wavelength-phase difference data set, the servo motor is controlled to rotate counterclockwise or clockwise by m calibration step rotation intervals, and the spectrometer is controlled to perform N scans, m ≥ 2, N ≥ 3;

[0100] SC2ˋ: Calculate the average wavelength of the spectrum data scanned each time in step SC1ˋ, and take the average value of N average wavelengths as the average wavelength corresponding to each calibration step rotation interval;

[0101] SC3: Control the servo motor to rotate clockwise or counterclockwise by 1 calibration step rotation interval. The rotation direction is opposite to the rotation direction of step SC1. Control the spectrometer to scan N times, N ≥ 3;

[0102] SC4: Calculate the average wavelength of the spectrum data scanned each time in step SC3, and use the average value of the N average wavelengths as the average wavelength corresponding to each calibration step rotation interval;

[0103] SC5: Repeat steps SC3 and SC4 L times, generate a linear curve based on the average wavelength and phase difference of L+1 times, and calculate the slope, which is used as the optimal correction slope K of the weak value amplification linear region of the optimal segment. CO-i When L is an even number, the average wavelength of the L / 2+1th time is taken as the preferred correction origin average wavelength λ of the preferred weak value amplification linear region. CO-i When L is an odd number, the average wavelength of the (L+1) / 2th order is taken as the average wavelength of the optimal correction origin in the weak value amplification linear region of the optimal segment λ CO-i , where L≥4.

[0104] (III) Sample measurement

[0105] See also Figure 3 Based on the setting of the above optical phase detection system, the processor measures the optical phase of the sample to be measured by the following method, including the following steps.

[0106] S1: Obtain the initial position of the servo motor at the initial moment, and obtain the initial spectrum of the spectrometer at the initial moment; determine whether there are double peaks in the initial spectrum:

[0107] If yes, execute step S2;

[0108] If not, go to step S3.

[0109] See also Figure 4 a and Figure 4 b, Figure 4 a and Figure 4 b shows an example of a double peak in the spectrogram.

[0110] S2: Control the spectrometer to scan the spectrum of the sample to be tested and obtain the spectrum data at the current moment; calculate the average wavelength at the current moment based on the spectrum data at the current moment; obtain the slope of the segmented weak value amplification linear region corresponding to the average wavelength at the current moment, the average wavelength at the origin, and the initial position and current position of the servo motor to calculate the optical phase of the sample to be tested

[0111]

[0112] Where: b t represents the current position of the servo motor, b0 represents the initial position of the servo motor, d represents the phase amount introduced by the phase compensator corresponding to the minimum rotation interval of the servo motor, and λ t Indicates the average wavelength calculated from the current spectral data, λ i Represents λ t The average wavelength of the origin corresponding to the segmented weak value amplification linear region, K i Represents λ t The slope corresponding to the linear region of the segmented weak value amplification.

[0113] Furthermore, in order to make the measurement area in the area with the best linear performance in the weak value amplification linear region and further improve the measurement accuracy, step S2 also includes judging and adjusting whether the average wavelength at the current moment is in the preferred weak value amplification linear region. For details, please refer to Figure 5 , S2 includes the following sub-steps.

[0114] S21: Control the spectrometer to scan the spectrum of the sample to be tested to obtain the spectrum data at the current moment; and calculate the average wavelength and total light intensity according to the spectrum data at the current moment.

[0115] S22: judging whether the phase difference between the horizontal polarization component and the vertical polarization component of the sample light at the current moment is in the preferred weak value amplification linear region according to the average wavelength and the total light intensity:

[0116] If yes, execute step S23;

[0117] If not, execute step S24.

[0118] The average wavelength of each segmented weak value amplification linear region corresponds to a range. For example, 1530nm~1540nm is the average wavelength range of the first segmented weak value amplification linear region, and 1540nm~1550nm is the average wavelength range of the second segmented weak value amplification linear region. Assuming that the average wavelength range of the preferred segment weak value amplification linear region is 1560nm~1570nm, and the average wavelength of the sample light at the current moment is 1566nm, which is between 1560nm and 1570nm, then it can be determined that the phase difference between the horizontal polarization component and the vertical polarization component of the current sample light is in the set preferred segment weak value amplification linear region.

[0119] S23: Obtain the preferred slope of the preferred segment weak value amplification linear region corresponding to the average wavelength and the preferred origin average wavelength, and calculate the optical phase of the sample to be tested according to the average wavelength, the preferred slope, the preferred origin average wavelength, the initial position and the current position of the servo motor. satisfy:

[0120]

[0121] Where: b t represents the current position of the servo motor, b0 represents the initial position of the servo motor, d represents the phase amount introduced by the phase compensator corresponding to the minimum rotation interval of the servo motor, and λ t Indicates the average wavelength calculated from the current spectral data, λ O-i Represents λ t The average wavelength of the optimal origin corresponding to the weak value amplification linear region of the optimal segment, K O-i Represents λ t The preferred slope corresponding to the weak value amplification linear region in the preferred segment.

[0122] Furthermore, if the preferred segment weak value amplification linear region corresponding to the preferred slope K used in step S22 is O-i and the optimal origin average wavelength λ O-i is the corrected preferred correction slope K CO-i and the optimal correction origin average wavelength λ CO-i , then the optical phase of the sample to be measured satisfy:

[0123]

[0124] Where: CO-i Represents λ t The average wavelength of the optimal correction origin corresponding to the weak value amplification linear region of the optimal segment, K CO-i Represents λ t The preferred correction slope corresponding to the weak value amplification linear region of the preferred segment.

[0125] S24: Obtain the average wavelength of the origin of the weak value amplification linear region of the preferred segment of the cycle, and calculate the wavelength deviation between the average wavelength of the origin and the average wavelength; control the servo motor to rotate clockwise or counterclockwise by a number of data acquisition step rotation intervals according to the wavelength deviation, and execute step S21.

[0126] S3: Control the servo motor to rotate a data collection step rotation interval. According to the wavelength change trend and light intensity change trend of the average wavelength and total light intensity before and after the rotation, combined with the average wavelength-phase difference data set, control the servo motor to rotate clockwise or counterclockwise for a number of data collection step rotation intervals, and execute step S2.

[0127] Specifically include the following steps.

[0128] S31: Control the spectrometer to scan the spectrum of the sample to be tested to obtain the spectrum data before rotation; and calculate the average wavelength and total light intensity before rotation according to the spectrum data before rotation.

[0129] S32: Control the servo motor to rotate clockwise or counterclockwise by a data acquisition step rotation interval;

[0130] S33: Control the spectrometer to scan the spectrum of the sample to be tested to obtain the spectrum data after rotation; and calculate the average wavelength after rotation and the total light intensity after rotation according to the spectrum data after rotation.

[0131] S34: According to the wavelength change trend and the light intensity change trend of the average wavelength and total light intensity before rotation and the average wavelength and total light intensity after rotation, combined with the average wavelength-phase difference data set, control the servo motor to rotate clockwise or counterclockwise by a number of data collection step rotation intervals, and execute step S2.

[0132] The terms used in the embodiments of the present application are only for the purpose of describing specific embodiments, and are not intended to limit the embodiments of the present application. The singular forms of "a", "said" and "the" used in the embodiments of the present application and the claims are also intended to include plural forms, unless the context clearly indicates other meanings. It should also be understood that, unless otherwise specified, "multiple" and "several" refer to two or more; "and / or" refers to and includes any or all possible combinations of one or more associated listed items; "first", "second", "third", etc. are only used to distinguish, rather than to describe a specific order or sequence, and cannot be understood as indicating or implying relative importance. When the above description relates to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. In the description of the present application, for those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to the specific circumstances.

[0133] The above embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several modifications and improvements can be made without departing from the concept of the present invention, and the present invention is also intended to include these modifications and modifications.

Claims

1. An optical phase detection system based on quantum weak value amplification, comprising a light emitting unit, a front light polarization selection unit, a phase compensator, a sample coupling unit, a rear light polarization selection unit, a spectrometer, and a processor, which are sequentially in the same optical path; wherein, The phase compensator introduces a phase quantity by controlling a servo motor electrically connected thereto, the angle between the transmission axis of the front selection light polarization unit and the horizontal positive direction is +(π / 4)rad, and the angle between the transmission axis of the rear selection light polarization unit and the horizontal positive direction is -(π / 4)rad, the processor is electrically connected and / or communicatively connected to the servo motor and the spectrometer, and is characterized in that the processor obtains the optical phase of the sample to be measured by the following method: S1: Obtain the initial position of the servo motor at the initial moment, and obtain the initial spectrum of the spectrometer at the initial moment; determine whether there are double peaks in the initial spectrum: If yes, execute step S2; If no, proceed to step S3; S2: Control the spectrometer to scan the spectrum of the sample to be tested and obtain the spectrum data at the current moment; calculate the average wavelength at the current moment based on the spectrum data at the current moment; obtain the slope of the corresponding segmented weak value amplification linear region of the average wavelength at the current moment in the average wavelength-phase difference data set, the average wavelength at the origin, and the initial position and current position of the servo motor to calculate the optical phase of the sample to be tested Where: b t represents the current position of the servo motor, b0 represents the initial position of the servo motor, d represents the phase amount introduced by the phase compensator corresponding to the minimum rotation interval of the servo motor, and λ t Indicates the average wavelength calculated from the current spectral data, λ i Represents λ t The average wavelength of the origin corresponding to the segmented weak value amplification linear region, K i Represents λ t The slope corresponding to the linear region of the segmented weak value amplification; S3: Control the servo motor to rotate a data collection step rotation interval, according to the wavelength change trend and light intensity change trend of the average wavelength and total light intensity before and after the rotation, combined with the average wavelength-phase difference data set, control the servo motor to rotate clockwise or counterclockwise for a number of data collection step rotation intervals until double peaks appear in the spectrum graph, and execute step S2.

2. The optical phase detection system according to claim 1, characterized in that: The slope K and the origin average wavelength λ corresponding to the segmented weak value amplification linear region used in step S2 are the preferred slope K of the preferred segment weak value amplification linear region in the weak value amplification linear region. O-i and the optimal origin average wavelength λ O-i .

3. The optical phase detection system according to claim 2, characterized in that: The preferred segmented weak value amplification linear region is a linear region corresponding to the maximum absolute value of the slope of each segmented weak value amplification linear region of the weak value amplification linear region.

4. The optical phase detection system according to claim 3, characterized in that: The optimal slope K of the linear region is enlarged by using the optimal segment weak value O-i and the optimal origin average wavelength λ O-i Calculate the optical phase of the sample to be measured Step S2 includes the following sub-steps: S21: Control the spectrometer to scan the spectrum of the sample to be tested to obtain the spectrum data at the current moment; calculate the average wavelength and total light intensity according to the spectrum data at the current moment; S22: judging whether the phase difference between the horizontal polarization component and the vertical polarization component of the sample light at the current moment is in the preferred weak value amplification linear region according to the average wavelength and the total light intensity: If yes, execute step S23; If no, execute step S24; S23: Obtain the preferred slope of the preferred segment weak value amplification linear region corresponding to the average wavelength and the preferred origin average wavelength, and calculate the optical phase of the sample to be tested according to the average wavelength, the preferred slope, the preferred origin average wavelength, the initial position and the current position of the servo motor. satisfy: Where: b t represents the current position of the servo motor, b0 represents the initial position of the servo motor, d represents the phase amount introduced by the phase compensator corresponding to the minimum rotation interval of the servo motor, and λ t Indicates the average wavelength calculated from the current spectral data, λ O-i Represents λ t The average wavelength of the optimal origin corresponding to the weak value amplification linear region of the optimal segment, K O-i Represents λ t The preferred slope corresponding to the weak value amplification linear region of the preferred segment; S24: Obtain the average wavelength of the origin of the weak value amplification linear region of the preferred segment of the cycle, and calculate the wavelength deviation between the average wavelength of the origin and the average wavelength; control the servo motor to rotate clockwise or counterclockwise by a number of data acquisition step rotation intervals according to the wavelength deviation, and execute step S21.

5. The optical phase detection system according to claim 4, characterized in that: The preferred slope K corresponding to the linear region of the preferred segment weak value amplification adopted in step S22 is O-i and the optimal origin average wavelength λ O-i is the corrected preferred correction slope K CO-i and the optimal correction origin average wavelength λ CO-i , the optical phase of the sample to be measured satisfy: Where: CO-i Represents λ t The average wavelength of the optimal correction origin corresponding to the weak value amplification linear region of the optimal segment, K CO-i Represents λ t The preferred correction slope corresponding to the weak value amplification linear region of the preferred segment.

6. The optical phase detection system according to claim 5, characterized in that: The preferred correction slope K CO-i and the optimal correction origin average wavelength λ CO-i Obtained by the following method: SC1`: without placing the sample to be tested, after making the spectral data located in the preferred weak value amplification linear region according to the wavelength-phase relationship of the average wavelength-phase difference data set, the servo motor is controlled to rotate counterclockwise or clockwise by m calibration step rotation intervals, and the spectrometer is controlled to perform N scans, m ≥ 2, N ≥ 3; SC2': Calculate the average wavelength of the spectrum data scanned each time in step SC1', and take the average value of N average wavelengths as the average wavelength corresponding to each calibration step rotation interval; SC3`: Control the servo motor to rotate clockwise or counterclockwise by 1 calibration step rotation interval, the rotation direction is opposite to the rotation direction of step SC1, and control the spectrometer to scan N times, N ≥ 3; SC4': Calculate the average wavelength of the spectrum data scanned each time in step SC3', and take the average value of the N average wavelengths as the average wavelength corresponding to each calibration step rotation interval; SC5': Repeat steps SC3' and SC4' L times, generate a linear curve based on the average wavelength and phase difference of L+1 times and calculate the slope, and use the slope as the preferred correction slope K of the weak value amplification linear region of the preferred segment CO-i When L is an even number, the average wavelength of the L / 2+1th time is taken as the optimal correction origin average wavelength λ of the optimal weak value amplification linear region. CO-i When L is an odd number, the average wavelength of the (L+1) / 2th order is taken as the average wavelength of the optimal correction origin in the weak value amplification linear region of the optimal segment λ CO-i , where L≥4.

7. The optical phase detection system according to claim 1, characterized in that: The slope K corresponding to the linear region of the segmented weak value amplification adopted in step S2 is i and the average wavelength λ at the origin i is the corrected slope K C-i and the average wavelength λ of the corrected origin C-i , the optical phase of the sample to be measured satisfy: Where: CO-i Represents λ t The average wavelength of the corrected origin corresponding to the linear region of the segmented weak value amplification, K CO-i Represents λ t The correction slope corresponding to the linear region of the segmented weak value amplification.

8. The optical phase detection system according to claim 7, characterized in that: The correction slope K C-i and the average wavelength λ of the corrected origin C-i Obtained by the following method: SC1: No sample is placed. According to the wavelength-phase relationship of the average wavelength-phase difference data set, the spectral data is located in the segmented weak value amplification linear region corresponding to the average wavelength at the current moment. The servo motor is controlled to rotate counterclockwise or clockwise by m calibration step rotation intervals, and the spectrometer is controlled to perform N scans, m ≥ 2, N ≥ 3; SC2: Calculate the average wavelength of the spectrum data scanned each time in step SC1, and use the average value of N average wavelengths as the average wavelength corresponding to each calibration step rotation interval; SC3: Control the servo motor to rotate clockwise or counterclockwise by 1 calibration step rotation interval, and the rotation direction is opposite to the rotation direction of step SC1, and control the spectrometer to scan N times, N ≥ 3; SC4: Calculate the average wavelength of the spectrum data scanned each time in step SC3, and use the average value of N average wavelengths as the average wavelength corresponding to each calibration step rotation interval; SC5: Repeat steps SC3 and SC4 L times, generate a linear curve based on the average wavelength and phase difference of L+1 times and calculate the slope, and use the slope as the correction slope K of the linear region of the segmented weak value amplification C-i When L is an even number, the average wavelength of the L / 2+1th time is taken as the average wavelength λ of the correction origin of the segmented weak value amplification linear region C-i When L is an odd number, the average wavelength of the (L+1) / 2th time is taken as the average wavelength λ of the correction origin of the segmented weak value amplification linear region C-i , where L≥4.

9. The optical phase detection system according to any one of claims 1 to 8, characterized in that: The average wavelength-phase difference data set is constructed by the following method: SA1: Without placing the sample to be tested, control the servo motor to rotate counterclockwise or clockwise to the limit of the set total rotation range; SA2: Control the servo motor to rotate clockwise or counterclockwise by 1 data acquisition step rotation interval, the rotation direction is opposite to the rotation direction of step SA1, and control the spectrometer to scan N times, N ≥ 3; SA3: Calculate the average wavelength of the spectrum data scanned each time in step SA2, and use the average value of N average wavelengths as the average wavelength corresponding to each data acquisition step rotation interval; SA4: Repeat steps SA2 and SA3 until the servo motor rotates to the set total rotation range, and draw an average wavelength-phase difference graph according to the phase difference and average wavelength corresponding to each data collection step rotation interval; SA5: Calculate the slopes of each segmented weak value amplification linear region K1, K2, ..., K i ,...,K n ; SA6: Calculate the data acquisition step rotation interval M corresponding to each segmented linear region. When M is an even number, the average wavelength of the M / 2+1th time is used as the average wavelength of the origin of the segmented weak value amplification linear region. When M is an odd number, the average wavelength of the (M+1) / 2th time is used as the average wavelength of the origin of the segmented weak value amplification linear region.

10. The optical phase detection system according to claim 9, characterized in that: The step S3 comprises the following sub-steps: S31: Control the spectrometer to scan the spectrum of the sample to be tested to obtain the spectrum data before rotation; calculate the average wavelength and total light intensity before rotation according to the spectrum data before rotation; S32: Control the servo motor to rotate clockwise or counterclockwise by a data acquisition step rotation interval; S33: Control the spectrometer to scan the spectrum of the sample to be tested to obtain spectrum data after rotation; calculate the average wavelength after rotation and the total light intensity after rotation according to the spectrum data after rotation; S34: According to the wavelength change trend and the light intensity change trend of the average wavelength and total light intensity before rotation and the average wavelength and total light intensity after rotation, combined with the average wavelength-phase difference data set, control the servo motor to rotate clockwise or counterclockwise by a number of data collection step rotation intervals, and execute step S2.

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