Polarization EMCCD device parameter test system

Abstract

The invention discloses a polarization EMCCD device parameter testing system in the technical field of photoelectric measurement. The polarization EMCCD device parameter testing system comprises a uniform light source, a polarization angle control module, a camera obscura and an upper computer parameter testing system. The camera obscura is used for placing a polarization EMCCD device to be tested; the uniform light source is used for generating uniform light with target wavelength and target light intensity and irradiating the uniform light to the polarization angle control module, and the polarization angle control module is used for converting the uniform light into linearly polarized light with a target polarization angle and irradiating the linearly polarized light to the polarization EMCCD device to be measured. The upper computer parameter testing system is used for being in communication connection with the uniform light source, the polarization angle control module and the polarization EMCCD device to be tested to perform parameter testing; the parameter test system provided by the invention can realize the functions of serial port control, image acquisition, parameter test and the like, has a visual graphical user interface, is convenient for a user to operate and monitor, and refers to the numerical value of each parameter in real time, so that the performance of the integrated polarization EMCCD device parameters is objectively evaluated.

Description

Technical Field

[0001] The invention relates to the technical field of photoelectric measurement, and in particular to a polarization EMCCD device parameter testing system. Background Art

[0002] Polarization imaging can provide polarization information related to the target surface's water content, texture, conductivity, roughness and other surface characteristics. By using the difference in polarization characteristics between the target and the background, military targets hidden in the natural background can be highlighted. Polarization imaging technology can highlight man-made targets and make up for the shortcomings of traditional military reconnaissance to a certain extent. For typical military strike targets, through polarization imaging technology, the polarization vector information can be effectively used to enhance image contrast and improve the signal-to-noise ratio, thereby improving the quality of target detection imaging and detection accuracy in military applications, providing an effective means for timely detection of enemy targets.

[0003] Based on the imaging of integrated polarization EMCCD devices, the low-light detection capability of EMCCD and the characteristics of polarization imaging are fully combined to obtain the light intensity information and polarization information of the measured target at the same time, break through the key technologies such as the extraction and solution of polarization information, the fusion of polarization target light intensity and polarization image, and improve the recognition ability of false, camouflaged, and stealth artificial targets in complex battlefield environments such as rain, fog, and haze, thereby improving the ability to obtain intelligence on the battlefield and providing a technical means for enhancing the perception capability of optoelectronic reconnaissance and detection equipment systems. Usually, before the image sensor is applied, it is the first thing to test its various performance parameters. According to the test results, it can be judged whether the device meets the performance requirements of the entire system to ensure the overall performance indicators of the system. At present, there are relatively few studies on the testing of polarization EMCCD devices, which cannot meet the needs of objectively evaluating the performance of polarization EMCCD device parameters. Summary of the invention

[0004] The purpose of the present invention is to overcome the deficiencies in the prior art and provide a polarization EMCCD device parameter testing system to solve the technical problem that the prior art lacks technical means for objectively evaluating the performance of polarization EMCCD device parameters.

[0005] To achieve the above object, the present invention is implemented by adopting the following technical solutions: The invention provides a polarization EMCCD device parameter testing system, comprising a uniform light source, a polarization angle control module, a dark box and a host computer parameter testing system; the dark box is used for placing a polarization EMCCD device to be tested; the uniform light source is used for generating uniform light of a target wavelength and a target light intensity and irradiating the polarization angle control module; the polarization angle control module is used for converting the uniform light into linearly polarized light of a target polarization angle and irradiating the polarization EMCCD device to be tested; the host computer parameter testing system is used for communicating with the uniform light source, the polarization angle control module and the polarization EMCCD device to be tested to perform parameter testing.

[0006] Optionally, the uniform light source includes a halogen tungsten lamp, a monochromator, a light attenuation module and an integrating sphere arranged in sequence, the halogen tungsten lamp emits continuous and stable original light; the monochromator separates monochromatic light of a target wavelength from the original light; the light attenuation module adjusts the monochromatic light to a target light intensity and outputs uniform light through the integrating sphere.

[0007] Optionally, the polarization angle control module includes a depolarizer and a polarizer, and the uniform light is comprehensively converted by the depolarizer and the polarizer to obtain linearly polarized light of a target polarization angle.

[0008] Optionally, the parameter test includes: The wavelength of the uniform light As a control variable, obtain the current output by the standard detector in the polarization EMCCD device to be tested and voltage , and calculate the spectral response rate of the standard detector : ; In the formula, is the standard detector wavelength The calibration value of is the standard detector area, is the integration time; A spectral response rate curve is drawn according to the wavelengths within the target wavelength range and their corresponding spectral response rates, as a parameter test result of the standard detector.

[0009] Optionally, the parameter test includes: The polarization angle of linearly polarized light As a control variable, the polarization response of the polarization photosensitive element in the polarization EMCCD device to be tested is obtained. , and calculate the polarization transmittance of the polarization photosensitive element : ; In the formula, is the spectral response rate corresponding to the current wavelength of uniform light; The polarization transmittance corresponding to the preset multiple polarization angles is averaged to obtain the final polarization transmittance of the polarization photosensor.

[0010] Optionally, the parameter test includes: The polarization angle of linearly polarized light As a control variable, the pixel maximum value of the grayscale image of the polarization photosensitive element in the polarization EMCCD device to be tested is obtained. and pixel minimum , and calculate the extinction ratio of the polarization light sensitive element : ; The final extinction ratio of the polarization photosensor is obtained by performing an average calculation based on the extinction ratios corresponding to a plurality of preset polarization angles.

[0011] Optionally, the parameter test includes: Turn off the uniform light source, obtain the collected image of the polarization EMCCD device to be tested, and record it as the background image; Turning on a uniform light source to obtain an image of the polarized EMCCD device to be tested, which is recorded as an illumination image; Adjusting the intensity of the uniform light until the grayscale value of the white light channel of the illumination image reaches 90% of the maximum grayscale value, thereby obtaining a useful information image; The signal-to-noise ratio of the collected image of the polarization EMCCD device to be tested is calculated according to the background image and the useful information image: ; In the formula, is the variance of the useful information image and the background image.

[0012] Compared with the prior art, the present invention has the following beneficial effects: The present invention provides a polarization EMCCD device parameter testing system, which generates uniform light of target wavelength and target light intensity through a uniform light source and irradiates the uniform light to a polarization angle control module, converts the uniform light into linear polarized light of target polarization angle through the polarization angle control module and irradiates the polarization EMCCD device to be tested, and performs parameter testing through a host computer parameter testing system, which is connected to the uniform light source, polarization angle control module and polarization EMCCD device to be tested in communication. The host computer parameter testing system can realize functions such as serial port control, image acquisition and parameter testing, and has an intuitive graphical user interface, which is convenient for users to operate and monitor, and refer to the values ​​of various parameters in real time, thereby realizing objective evaluation of the performance of integrated polarization EMCCD device parameters. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 is a structural diagram of a polarization EMCCD device parameter testing system provided by an embodiment of the present invention; Figure 2 is a schematic diagram of a real-time image display interface provided by an embodiment of the present invention; Figure 3 is a schematic diagram of a response band test interface provided by an embodiment of the present invention; Figure 4 is a schematic diagram of a transmittance and extinction ratio parameter calculation interface provided by an embodiment of the present invention; Figure 5 It is a schematic diagram of a signal-to-noise ratio calculation interface provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0014] The present invention will be further described below in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and cannot be used to limit the protection scope of the present invention.

[0015] Embodiment 1:

[0016] like Figure 1 As shown, an embodiment of the present invention provides a polarization EMCCD device parameter testing system, including a uniform light source, a polarization angle control module, a dark box and a host computer parameter testing system; the dark box is used to place the polarization EMCCD device to be tested; the uniform light source is used to generate uniform light of target wavelength and target light intensity and irradiate it to the polarization angle control module, the polarization angle control module is used to convert the uniform light into linear polarized light of the target polarization angle and irradiate it to the polarization EMCCD device to be tested, and the host computer parameter testing system is used to communicate with the uniform light source, the polarization angle control module and the polarization EMCCD device to be tested to perform parameter testing.

[0017] By placing the polarized EMCCD device to be tested in a dark box, the influence of surrounding stray light on the polarized EMCCD device can be avoided.

[0018] A uniform light source is a light source with uniform brightness distribution, and its brightness is evenly distributed over the entire area, without uneven brightness or hot spots. This light source usually includes multiple light-emitting units, which are arranged and controlled reasonably so that light can be emitted evenly. Specifically in this embodiment, the uniform light source includes a halogen tungsten lamp, a monochromator, a light attenuation module and an integrating sphere arranged in sequence, the halogen tungsten lamp emits continuous and stable original light; the monochromator separates monochromatic light of the target wavelength from the original light; the light attenuation module adjusts the monochromatic light to the target light intensity (used to produce the low light conditions required for the test), and outputs uniform light through the integrating sphere.

[0019] The polarization angle control module is a device that can accurately control and adjust the polarization state of light waves. It can achieve precise control of the polarization state of light waves by changing the ratio or angle of the electric field vibration direction in the light wave. Specifically in this embodiment, the polarization angle control module includes a depolarizer and a polarizer. The depolarizer can convert the light wave originally having a specific polarization direction into non-polarized light with uniform distribution of vibration intensity in all directions; the polarizer can convert the light originally propagating in all directions into linearly polarized light that propagates in only one direction. The uniform light is comprehensively converted by the depolarizer and the polarizer to obtain linearly polarized light of the target polarization angle.

[0020] The host computer parameter test system runs on the PC side. In the parameter test system, according to the test method of the polarization EMCCD device to be tested, the parameter interface is written, such as the image display, corresponding band, transmittance, extinction ratio, signal-to-noise ratio and other parameter calculation interfaces.

[0021] To achieve the above object, the testing method of the present invention comprises: 1) Follow Figure 1 As shown, correctly connect various hardware devices, ensure the safety of power supply during each period, and close the darkroom tightly; then turn on the host computer parameter test system and start the test.

[0022] 2) If Figure 2 It is a real-time image display module, which allows testers to check at any time whether the image transmitted from the lower computer is correct and make timely adjustments.

[0023] 3) The upper computer sends commands to connect to the lower computer, and controls the working status of the data acquisition circuit board of the lower computer through various serial port commands, so that the data collected by the lower computer is transmitted to the upper computer, and then the data is processed.

[0024] 4) If Figure 3 The following is a response band test module, which tests the response rate of the device wavelength in a given wavelength range, draws a curve of wavelength and response, and obtains the spectral response curve and spectral range. Specifically, it includes: The wavelength of the uniform light As a control variable, obtain the current output by the standard detector in the polarization EMCCD device to be tested and voltage , and calculate the spectral response rate of the standard detector : ; In the formula, is the standard detector wavelength The calibration value of is the standard detector area, is the integration time; The spectral response rate curve is drawn according to the wavelength within the target wavelength range and its corresponding spectral response rate as the parameter test result of the standard detector. Figure 3 The data is displayed in real time for users to view.

[0025] 5) If Figure 4 The figure shows the transmittance and extinction ratio parameter calculation module. The transmittance parameter calculation process is as follows: The polarization angle of linearly polarized light As a control variable, obtain the polarization response of the polarization photosensitive element in the polarization EMCCD device to be tested , and calculate the polarization transmittance of the polarization photosensitive element : ; In the formula, is the spectral response rate corresponding to the current wavelength of uniform light; The polarization transmittance of the final polarization photosensor is obtained by performing an average calculation based on the polarization transmittances corresponding to the preset multiple polarization angles.

[0026] Specifically in this embodiment, , the polarization transmittance of the photosensitive elements in the four polarization directions in the visible light band at different incident polarization angles is obtained Finally, the transmittance of the entire chip can be obtained by averaging these four polarization transmittances. The calculation result is Figure 4 Real-time display.

[0027] 6) If Figure 4 The calculation process of the extinction ratio parameter is as follows: The polarization angle of linearly polarized light As a control variable, obtain the pixel maximum value of the grayscale image of the polarization photosensitive element in the polarization EMCCD device to be tested and pixel minimum , and calculate the extinction ratio of the polarization photosensitive element : ; The extinction ratio of the final polarization photosensor is obtained by performing an average calculation based on the extinction ratios corresponding to the preset multiple polarization angles.

[0028] Specifically in this embodiment, the extinction ratios of the photosensitive elements in the four polarization directions are calculated as follows: , calculate the average of these four extinction ratios to get the extinction ratio of the entire chip. Figure 4 The extinction ratio values ​​for each polarization and the extinction ratio value for the entire chip can be seen in .

[0029] 7) If Figure 5 The figure shows the signal-to-noise ratio calculation module. The specific calculation process is as follows: Turn off the uniform light source and obtain the collected image of the polarized EMCCD device to be tested, which is recorded as the background image; Turn on the uniform light source and obtain the collected image of the polarized EMCCD device to be tested, which is recorded as the illumination image; The intensity of the uniform light is adjusted until the gray value of the white light channel of the illumination image reaches 90% of the maximum gray value, and a useful information image is obtained; Calculate the signal-to-noise ratio of the collected image of the polarization EMCCD device to be tested based on the background image and the useful information image: ; In the formula, is the variance of the useful information image and the background image.

[0030] The calculated signal-to-noise ratio value will be displayed on Figure 5 middle.

[0031] The embodiment of the present invention designs a host computer parameter testing system based on the testing principle and method of integrated polarization EMCCD devices. The system can debug the working state of the slave computer, and the image data can be viewed in real time on the host computer. In combination with the testing principle and method, according to the parameter characteristics such as response band, transmittance, extinction ratio, signal-to-noise ratio, etc., a corresponding image data analysis algorithm is written to realize the EMCCD polarization integrated device parameter testing interface.

[0032] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A polarization EMCCD device parameter testing system, characterized in that: It includes a uniform light source, a polarization angle control module, a dark box and a host computer parameter testing system; the dark box is used to place the polarization EMCCD device to be tested; the uniform light source is used to generate uniform light of target wavelength and target light intensity and irradiate the polarization angle control module; the polarization angle control module is used to convert the uniform light into linearly polarized light of target polarization angle and irradiate the polarization EMCCD device to be tested; the host computer parameter testing system is used to communicate with the uniform light source, the polarization angle control module and the polarization EMCCD device to be tested to perform parameter testing.

2. The polarization EMCCD device parameter testing system according to claim 1, characterized in that: The uniform light source includes a halogen tungsten lamp, a monochromator, a light attenuation module and an integrating sphere which are arranged in sequence. The halogen tungsten lamp emits continuous and stable original light; the monochromator separates monochromatic light of a target wavelength from the original light; the light attenuation module adjusts the monochromatic light to a target light intensity and outputs uniform light through the integrating sphere.

3. The polarization EMCCD device parameter testing system according to claim 1, characterized in that: The polarization angle control module comprises a depolarizer and a polarizer, and the uniform light is comprehensively converted by the depolarizer and the polarizer to obtain linearly polarized light of a target polarization angle.

4. The polarization EMCCD device parameter testing system according to claim 1, characterized in that: The parameter tests include: The wavelength of the uniform light As a control variable, obtain the current output by the standard detector in the polarization EMCCD device to be tested and voltage , and calculate the spectral response rate of the standard detector : ； In the formula, is the standard detector wavelength The calibration value of is the standard detector area, is the integration time; A spectral response rate curve is drawn according to the wavelengths within the target wavelength range and their corresponding spectral response rates, as a parameter test result of the standard detector.

5. The polarization EMCCD device parameter testing system according to claim 1, characterized in that: The parameter tests include: The polarization angle of linearly polarized light As a control variable, the polarization response of the polarization photosensitive element in the polarization EMCCD device to be tested is obtained. , and calculate the polarization transmittance of the polarization photosensitive element : ； In the formula, is the spectral response rate corresponding to the current wavelength of uniform light; The polarization transmittance corresponding to the preset multiple polarization angles is averaged to obtain the final polarization transmittance of the polarization photosensor.

6. The polarization EMCCD device parameter testing system according to claim 1, characterized in that: The parameter tests include: The polarization angle of linearly polarized light As a control variable, the pixel maximum value of the grayscale image of the polarization photosensitive element in the polarization EMCCD device to be tested is obtained. and pixel minimum , and calculate the extinction ratio of the polarization light sensitive element : ； The final extinction ratio of the polarization photosensor is obtained by performing an average calculation based on the extinction ratios corresponding to a plurality of preset polarization angles.

7. The polarization EMCCD device parameter testing system according to claim 1, characterized in that: The parameter tests include: Turn off the uniform light source, obtain the collected image of the polarization EMCCD device to be tested, and record it as the background image; Turning on a uniform light source to obtain an image of the polarized EMCCD device to be tested, which is recorded as an illumination image; Adjusting the intensity of the uniform light until the grayscale value of the white light channel of the illumination image reaches 90% of the maximum grayscale value, thereby obtaining a useful information image; The signal-to-noise ratio of the collected image of the polarization EMCCD device to be tested is calculated according to the background image and the useful information image: ； In the formula, is the variance of the useful information image and the background image.

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