A device for measuring spatial light polarization information in one body

Abstract

The application discloses a kind of integrated measuring spatial light polarization information device, comprising: linear polarizer, photoelectric detector, motor, single-chip microcomputer and liquid crystal color screen;The linear polarizer is connected with photoelectric detector, motor respectively;The single-chip microcomputer is connected with photoelectric detector, motor, liquid crystal color screen respectively;The expression of the electric signal detected by photoelectric detector conversion light intensity and the angle relationship of linear polarizer is: I=S0+cos2 theta S1+sin2 theta S2.The application has two kinds of working modes, polarization measurement mode and extinction ratio measurement mode respectively.The application has lower cost, and the device is also simpler.The application has smaller size, no additional wiring except a power cord, which increases the applicability of the application, and can measure laser polarization information in a more narrow space.The application has integrated features, and measurement information can be obtained directly without cooperating with host computer, which greatly improves experimental efficiency.

Description

Technical Field

[0001] This invention relates to the field of optical element technology, and more specifically to an integrated device for measuring spatial light polarization information. Background Technology

[0002] Currently, lasers have wide applications in many fields such as industry, medicine, and scientific research. In these applications, lasers with specific polarizations are often required, making the measurement of laser polarization states particularly important. There are two main methods for polarization state measurement: one is the mechanical modulation method (e.g., Thorlabs' PAX5710-T series) which uses polarization-modulating optical devices and motor drives to obtain different modulation results by changing the optical modulation devices; the other is the amplitude division method (e.g., Agilent's 8509 series polarization meter (1250nm-1600nm)) which uses beam splitters to divide the incident light into multiple paths, each containing different polarization modulation information. The results are recorded and calculated using four uniformly calibrated detectors, allowing for rapid calculation of the polarization characteristics of the light under test and real-time measurement.

[0003] While the above products offer high measurement accuracy, they are expensive and complex in structure, often requiring a host computer to operate in conjunction with them. For many environments where optical paths are constructed, we only need the ability to quickly measure the polarization state of light, without demanding high measurement accuracy. Therefore, developing a simple, practical, low-cost, and visualized integrated polarization analyzer for polarization state measurement results has significant practical value. Summary of the Invention

[0004] In view of this, in order to solve the above-mentioned problems in the prior art, the present invention proposes an integrated device for measuring spatial light polarization information, which has the characteristics of being integrated and can directly obtain measurement information without the need for a host computer, thus greatly improving experimental efficiency.

[0005] The present invention solves the above problems through the following technical means:

[0006] An integrated device for measuring spatial optical polarization information includes: a linear polarizer, a photodetector, a motor, a microcontroller, and an LCD screen;

[0007] The linear polarizer is connected to the photodetector and the motor, respectively.

[0008] The microcontroller is connected to the photodetector, the motor, and the LCD screen respectively;

[0009] For any incident light, if E x E y Let E be the electric vector of the polarized light in the X and Y vibration directions, respectively. 0x E0y The average value of the time t of the polarized light amplitude in the X and Y directions, i.e.

[0010]

[0011] Define its Stokes vector S = [S0 S1 S2 S3] T Then the formula for calculating S is:

[0012]

[0013] Where δ represents E x and E y The phase difference, S0 represents the total light intensity, S1 represents linearly polarized light in the horizontal or vertical direction, S2 represents linearly polarized light in the +45° or -45° direction, and S3 represents left-handed or right-handed circularly polarized light contained in the light ray. S0, S1, S2 and S3 are all real numbers.

[0014] When the transmission axis of the linear polarizer is θ away from the reference direction, the Mueller matrix M of the linear polarizer is... p Represented as:

[0015]

[0016] The Stokes vector S of the emitted light out for:

[0017]

[0018] Where S0′ represents the total light intensity of the emitted light, S1′ represents the linearly polarized light in the horizontal or vertical direction of the emitted light, S2′ represents the linearly polarized light in the +45° or -45° direction of the emitted light, and S3′ represents the left-handed or right-handed circularly polarized light contained in the emitted light.

[0019] The expression for the conversion of the electrical signal detected by the photodetector into light intensity I, and its relationship with the angle of the linear polarizer, are derived as follows:

[0020] I=S0+cos 2θS1+sin 2θS2 #(5).

[0021] Preferably, the working mode of the integrated device for measuring spatial light polarization information is polarization measurement mode: the motor controls the transmission axis of the linear polarizer to rotate one revolution starting from the horizontal direction each time. When θ is 0°, 45°, and 90° respectively, the light intensities detected by the photodetector are: I1=S0+S1, I2=S0+S2, I3=S0-S1. Solve the equations to get the values ​​of S0, S1, and S2 respectively. Then, calculate S3 from the equation set (2) to obtain the Stokes vector parameters of the incident light. It can calculate polarization information such as the degree of polarization (DOP); through microcontroller processing, the polarization information is output to the LCD color screen for display.

[0022] Preferably, the integrated device for measuring spatial light polarization information operates in extinction ratio measurement mode: the motor controls the linear polarizer to rotate one revolution, and the light intensity information is read in real time, with the maximum value P of the collected light intensity being recorded. max The minimum light intensity P min Through formula This allows us to obtain the extinction ratio ER; the microcontroller processes the data and performs calculations, outputting the extinction ratio ER and the light intensity during the waveplate rotation to the LCD screen to plot a curve of light intensity changing with angle; the microcontroller processes the data to make the motor control the linear polarizer to stop rotating when the photodetector measures the maximum light intensity. At this time, the transmission axis of the linear polarizer is the direction of the linear polarization component of the incident light. By observing the final transmission axis direction of the linear polarizer, we can quickly determine the direction of the linear polarization component of the incident light.

[0023] Preferably, the photodetector is a photodiode.

[0024] Preferably, the motor is a stepper motor.

[0025] Preferably, the LCD screen is an IPS LCD screen.

[0026] Compared with the prior art, the beneficial effects of the present invention include at least the following:

[0027] 1. Simple device and cost-saving: This invention consists of only a linear polarizer, a photodiode, a stepper motor, a microcontroller and an IPS LCD screen. Compared with products on the market, it has a lower cost and a simpler device.

[0028] 2. Small size and high applicability: In many experimental environments, optical components are often very close together. This invention is smaller in size and has no additional wiring except for a power line, which increases the applicability of this invention and allows for the measurement of laser polarization information in more confined spaces.

[0029] 3. Improved efficiency: This invention features an integrated design, allowing measurement information to be obtained directly without the need for a host computer, thus greatly improving experimental efficiency. Attached Figure Description

[0030] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0031] Figure 1 This is a schematic diagram of the integrated device for measuring spatial optical polarization information according to the present invention;

[0032] Explanation of reference numerals in the attached figures:

[0033] 1. Linear polarizer; 2. Photodiode; 3. Stepper motor; 4. Microcontroller; 5. IPS LCD screen. Detailed Implementation

[0034] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, the technical solutions of the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that the described embodiments are merely some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0035] like Figure 1 As shown, the present invention provides an integrated device for measuring spatial optical polarization information, comprising: a linear polarizer 1, a photodiode 2, a stepper motor 3, a microcontroller 4, and an IPS LCD color screen 5.

[0036] The linear polarizer 1 is connected to the photodiode 2 and the stepper motor 3, respectively.

[0037] The microcontroller 4 is connected to the photodiode 2, the stepper motor 3, and the IPS LCD screen 5, respectively.

[0038] For any incident light, if E x E y Let E be the electric vector of the polarized light in the X and Y vibration directions, respectively. 0x E 0y The average value of the time t of the polarized light amplitude in the X and Y directions, i.e.

[0039]

[0040] Define its Stoeks vector S = [S0 S1 S2 S3] T Then the formula for calculating S is:

[0041]

[0042] Where δ represents E x and E y The phase difference is given by S0, which represents the total light intensity, S1, which represents linearly polarized light in the horizontal or vertical direction, S2, which represents linearly polarized light in the +45° or -45° direction, and S3, which represents left-handed or right-handed circularly polarized light contained in the light ray. All four parameters are real numbers.

[0043] When the transmission axis of linear polarizer 1 is θ away from the reference direction, the Mueller matrix M of linear polarizer 1 is... p Represented as:

[0044]

[0045] The Stokes vector S of the emitted light out for:

[0046]

[0047] Where S0′ represents the total light intensity of the emitted light, S1′ represents the linearly polarized light in the horizontal or vertical direction of the emitted light, S2′ represents the linearly polarized light in the +45° or -45° direction of the emitted light, and S3′ represents the left-handed or right-handed circularly polarized light contained in the emitted light.

[0048] The expression for the conversion of the electrical signal detected by photodiode 2 into light intensity I, and the angular relationship between photodiode 2 and linear polarizer 1, are as follows:

[0049] I=S0+cos 2θS1+sin2θS2 #(5)

[0050] Based on the above analysis, this invention proposes two practical working modes:

[0051] (1) Polarization measurement mode: Stepper motor 3 controls the transmission axis of linear polarizer 1 to rotate one revolution starting from the horizontal direction each time. When θ is 0°, 45° and 90° respectively, the light intensities detected by photodiode 2 are: I1=S0+S1, I2=S0+S2, I3=S0-S1. Solving the equations simultaneously, the values ​​of S0, S1 and S2 can be obtained respectively. Then, from equation set (2), S3 can be calculated to obtain the Stokes vector parameters of the incident light. Through the formula: The polarization information, such as the degree of polarization (DOP), can then be calculated. This information is then processed by a microcontroller and output to an IPS LCD color screen for display.

[0052] (2) Extinction ratio measurement mode: Stepper motor 3 controls the linear polarizer 1 to rotate one revolution, and reads the light intensity information in real time. The maximum light intensity P collected is recorded. max The minimum light intensity P min Through formula The extinction ratio ER can then be obtained. The microcontroller 4 processes the data and performs calculations, outputting the extinction ratio ER and the light intensity during waveplate rotation to an IPS LCD screen 5 to plot a curve of light intensity versus angle. The microcontroller processes the data to cause the stepper motor 3 to stop rotating the linear polarizer 1 when the light intensity measured by the photodiode 2 is at its maximum. At this point, the transmission axis of the linear polarizer 1 is the direction of the linearly polarized component of the incident light. The direction of the linearly polarized component of the incident light can be quickly determined by observing the final transmission axis direction of the linear polarizer 1.

[0053] Compared with the prior art, the beneficial effects of the present invention include at least the following:

[0054] 1. Simple device and cost-saving: This invention consists of only a linear polarizer, a photodiode, a stepper motor, a microcontroller and an IPS LCD screen. Compared with products on the market, it has a lower cost and a simpler device.

[0055] 2. Small size and high applicability: In many experimental environments, optical components are often very close together. This invention is smaller in size and has no additional wiring except for a power line, which increases the applicability of this invention and allows for the measurement of laser polarization information in more confined spaces.

[0056] 3. Improved efficiency: This invention features an integrated design, allowing measurement information to be obtained directly without the need for a host computer, thus greatly improving experimental efficiency.

[0057] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention. Therefore, the scope of protection of this patent should be determined by the appended claims.

Claims

1. A device for measuring spatial optical polarization information in an integrated manner, characterized in that, include: Linear polarizers, photodetectors, motors, microcontrollers, and LCD screens; The linear polarizer is connected to the photodetector and the motor, respectively. The microcontroller is connected to the photodetector, the motor, and the LCD screen respectively; For any incident light, if E x E y Let E be the electric vector of the polarized light in the X and Y vibration directions, respectively. 0x E 0y The average value of the time t of the polarized light amplitude in the X and Y directions, i.e. Define its Stokes vector S = [S0 S1 S2 S3] T Then the formula for calculating S is: Where δ represents E x and E y The phase difference, S0 represents the total light intensity, S1 represents linearly polarized light in the horizontal or vertical direction, S2 represents linearly polarized light in the +45° or -45° direction, and S3 represents left-handed or right-handed circularly polarized light contained in the light ray. S0, S1, S2 and S3 are all real numbers. When the transmission axis of the linear polarizer is θ away from the reference direction, the Mueller matrix M of the linear polarizer is... p Represented as: The Stokes vector S of the emitted light out for: Where S0′ represents the total light intensity of the emitted light, S1′ represents the linearly polarized light in the horizontal or vertical direction of the emitted light, S2′ represents the linearly polarized light in the +45° or -45° direction of the emitted light, and S3′ represents the left-handed or right-handed circularly polarized light contained in the emitted light. The expression for the conversion of the electrical signal detected by the photodetector into light intensity I, and its relationship with the angle of the linear polarizer, are derived as follows: I=S0+cos 2θS1+sin 2θS2 #(5).

2. The integrated device for measuring spatial optical polarization information according to claim 1, characterized in that, The working mode of the integrated device for measuring spatial light polarization information is polarization measurement mode: the motor controls the transmission axis of the linear polarizer to rotate one revolution starting from the horizontal direction each time. When θ is 0°, 45°, and 90° respectively, the light intensities detected by the photodetector are: I1=S0+S1, I2=S0+S2, I3=S0-S1. Solve the equations to get the values ​​of S0, S1, and S2 respectively. Then, calculate S3 from the equation set (2) to obtain the Stokes vector parameters of the incident light. It can calculate polarization information such as the degree of polarization (DOP); through microcontroller processing, the polarization information is output to the LCD color screen for display.

3. The integrated device for measuring spatial optical polarization information according to claim 1, characterized in that, The integrated device for measuring spatial light polarization information operates in extinction ratio measurement mode: the motor controls the linear polarizer to rotate one revolution, and the light intensity information is read in real time, with the maximum light intensity value P collected being recorded. max The minimum light intensity P min Through formula This allows us to obtain the extinction ratio ER; the microcontroller processes the data and performs calculations, outputting the extinction ratio ER and the light intensity during the waveplate rotation to the LCD screen to plot a curve of light intensity changing with angle; the microcontroller processes the data to make the motor control the linear polarizer to stop rotating when the photodetector measures the maximum light intensity. At this time, the transmission axis of the linear polarizer is the direction of the linear polarization component of the incident light. By observing the final transmission axis direction of the linear polarizer, we can quickly determine the direction of the linear polarization component of the incident light.

4. The integrated device for measuring spatial optical polarization information according to claim 1, characterized in that, The photodetector is a photodiode.

5. The integrated device for measuring spatial optical polarization information according to claim 1, characterized in that, The motor is a stepper motor.

6. The integrated device for measuring spatial optical polarization information according to claim 1, characterized in that, The LCD screen is an IPS LCD screen.

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