Method, device and equipment for calibrating time characteristics of traveling wave amplitude splitting camera and medium

Abstract

The application belongs to the technical field of inertial confinement fusion measurement, and relates to a traveling wave split-frame camera time characteristic calibration method, device, equipment and medium, which comprises the following steps: splitting a pulse laser into a first light beam and a second light beam; acquiring a first light spot image of a microstrip under a direct current voltage, and a second light spot image corresponding to the second light beam when a split-frame camera is driven by a gating pulse and is synchronized with the pulse laser; based on the first light spot image, the gray scale distribution of a strip-shaped light spot in the second light spot image is respectively subjected to spatial light intensity correction; according to the gray scale peak position of the strip-shaped light spot in the corrected second light spot image, the transmission speed of the gating pulse on the microstrip is calculated, and a gain attenuation curve of the split-frame camera is fitted; the gray scale distribution of the strip-shaped light spot in the second light spot image is subjected to gain attenuation correction by using the gain attenuation curve, and the exposure time of the split-frame camera is calculated in combination with the transmission speed and the pixel size. The purpose is to improve the calibration precision and efficiency of the time characteristics of the split-frame camera.

Description

Technical Field

[0001] This invention relates to the field of inertial confinement fusion measurement technology, specifically to a method, apparatus, equipment, and medium for calibrating the time characteristics of a traveling wave framing camera. Background Technology

[0002] Traveling-wave framing cameras, as ultrafast diagnostic instruments possessing both high temporal resolution and two-dimensional spatial resolution, have wide applications in fields such as inertial confinement fusion and synchrotron radiation. They also provide crucial technical support for the study of transient phenomena in physics, chemistry, and biology. Accurate calibration of temporal characteristic parameters is key to evaluating equipment performance and ensuring the reliability of measurement data. Core temporal characteristics include exposure time and gain decay curves. Exposure time refers to the light-sensing time of a single image from the framing camera, while the gain decay curve characterizes how the gain of the image intensifier decreases from its peak value over time or spatial location after the image intensifier gate is activated.

[0003] In existing technologies, exposure time calibration mainly employs methods such as fiber bundle beam splitting to form a sequence of light spots, and direct irradiation with uniform short-pulse lasers combined with time-domain reflectometry (TDRS) measurements. Gain attenuation curve calibration includes methods such as flat-top long-pulse large-spot irradiation and multiple-trigger fitting with short-pulse ultraviolet lasers. The core problems of these existing methods are concentrated in three aspects: spatial non-uniformity interference, insufficient calibration accuracy, and low calibration efficiency. On the one hand, whether it is the fiber bundle-based sequence of light spots method or the direct irradiation method, the calibration results are easily affected by the modulation of non-uniformity in the spatial intensity distribution of the laser spot, thus introducing unavoidable measurement errors and reducing calibration accuracy. On the other hand, to overcome the influence of light source instability or imperfect pulse timing characteristics, some existing methods rely on energy monitoring between bursts or complex data correction steps, which not only increases system complexity and cost but also reduces the overall efficiency of the calibration process. Summary of the Invention

[0004] To reduce the impact of spatial non-uniformity and improve the accuracy and efficiency of time characteristic calibration for traveling wave framing cameras, this invention provides a method, apparatus, equipment, and medium for time characteristic calibration of traveling wave framing cameras. The specific technical solution adopted is as follows:

[0005] The first aspect of the present invention provides a method for calibrating the time characteristics of a traveling wave framing camera, the method comprising:

[0006] The pulsed laser beam is split into a first beam and a second beam that irradiate the microstrip of the framing camera, and the optical path of the second beam is adjustable.

[0007] Acquire a first spot image of the microstrip under DC voltage, and a second spot image of the corresponding second beam acquired at least two different optical paths when the framing camera is driven by a gated pulse and synchronized with a pulsed laser.

[0008] Based on the first light spot image, spatial light intensity correction is performed on the gray-level distribution of the strip-shaped light spots formed by the first beam and the second beam in the second light spot image.

[0009] Based on the position of the grayscale peak of the strip-shaped spot in the corrected second spot image, the transmission speed of the gating pulse on the microstrip is calculated, and based on the grayscale data of the corrected second spot image, the gain attenuation curve of the frame-segmented camera along the microstrip direction is fitted.

[0010] Gain attenuation correction is performed on the grayscale distribution of the strip-shaped light spots in the second light spot image using the gain attenuation curve, and the exposure time of the frame-splitting camera is calculated by combining the transmission speed and pixel size.

[0011] Further, acquiring second spot images at at least two different optical paths corresponding to the second beam when the framing camera is driven by a gated pulse and synchronized with the pulsed laser includes:

[0012] The optical path of the second beam is adjusted using an optical path adjustment device, so that the second beam produces at least two different optical path differences relative to the first beam.

[0013] For each optical path difference, the triggering time of the control gating pulse is synchronized with the emission time of the pulsed laser;

[0014] At each synchronization trigger moment, a second spot image containing two spatially separated strip-shaped light spots formed by the first beam and the second beam is acquired; wherein, for each optical path difference, a second spot image is acquired, thereby obtaining at least two second spot images.

[0015] Furthermore, based on the first light spot image, spatial intensity correction is performed on the grayscale distribution of the strip-shaped light spots formed by the first beam and the second beam in the second light spot image, including:

[0016] Based on the first light spot image, obtain the static light intensity distribution information of the two strip-shaped light spots formed by the first beam and the second beam;

[0017] Based on the second spot image under different optical path differences, the dynamic light intensity distribution information of the two strip-shaped spots formed by the first beam and the second beam is obtained;

[0018] The static light intensity distribution information is used to correct the dynamic light intensity distribution information to obtain the corrected grayscale distribution of the strip-shaped light spot.

[0019] Furthermore, based on the grayscale peak position of the strip-shaped spot in the corrected second spot image, the transmission speed of the gating pulse on the microstrip is calculated, including:

[0020] Based on the second spot images acquired under different optical path differences, the gray peak pixel positions of the gray distribution of the first strip-shaped spot formed by the first beam after correction and the gray peak pixel positions of the gray distribution of the second strip-shaped spot formed by the second beam are extracted respectively.

[0021] The propagation speed of the gating pulse along the microstrip length direction is calculated based on the pixel displacement of the grayscale peak pixel position of the second stripe spot relative to the grayscale peak pixel position of the first stripe spot under at least two different optical path differences.

[0022] Furthermore, based on the grayscale data of the corrected second spot image, the gain attenuation curve of the framing camera along the microstrip direction is fitted, including:

[0023] Based on the grayscale peak pixel positions of the first strip-shaped light spot extracted under at least two different optical path differences, a reference pixel position is determined.

[0024] Based on the reference pixel position, the corrected grayscale distribution data of the strip-shaped light spot corresponding to the second beam is normalized.

[0025] The gain attenuation curve is obtained by curve fitting of the normalized grayscale distribution data.

[0026] Furthermore, the gain attenuation correction of the grayscale distribution of the strip-shaped light spots in the second light spot image is performed using a gain attenuation curve, including:

[0027] Select a frame from the second spot image and use its corresponding corrected stripe spot grayscale distribution as the grayscale distribution to be corrected.

[0028] Based on the position of each pixel in the grayscale distribution to be corrected, the relative gain coefficient corresponding to each position is obtained by querying the gain attenuation curve;

[0029] The corrected grayscale distribution is obtained by dividing the grayscale value at each pixel location in the grayscale distribution to be corrected by the relative gain coefficient at that location.

[0030] Furthermore, the exposure time of the framing camera is calculated, including:

[0031] The modified grayscale distribution is fitted with a Gaussian function to obtain the fitted Gaussian curve;

[0032] Calculate the full width at half maximum (FWHM) of the fitted Gaussian curve and convert the FWHM to the corresponding pixel width;

[0033] Multiplying the pixel width by the cell size yields the equivalent spatial broadening length corresponding to the corrected grayscale distribution on the microstrip.

[0034] The exposure time of the frame-panel camera is calculated based on the equivalent spatial spanning length and transmission speed.

[0035] The second aspect of the present invention provides a time characteristic calibration device for a traveling-wave framing camera, employing the time characteristic calibration method for a traveling-wave framing camera described in the first aspect of the present invention. The device includes a femtosecond laser arranged along the optical path, an optical path beam splitting and adjustment unit, and a framing camera. The optical path beam splitting and adjustment unit is configured to split the pulsed laser beam into a first beam and a second beam, and adjust the optical path length of the second beam. The framing camera is configured to acquire images of a first spot and a second spot. It also includes:

[0036] The spatial light intensity correction module is configured to perform spatial light intensity correction on the grayscale distribution of the strip-shaped light spots formed by the first beam and the second beam in the second light spot image based on the first light spot image.

[0037] The gain attenuation curve fitting module is configured to calculate the transmission speed of the gating pulse on the microstrip based on the gray value peak position of the strip spot in the corrected second spot image, and to fit the gain attenuation curve of the frame-segmented camera along the microstrip direction based on the gray value data of the corrected second spot image.

[0038] The exposure time calculation module is configured to use the gain attenuation curve to correct the grayscale distribution of the strip-shaped light spots in the second light spot image, and calculate the exposure time of the frame camera by combining the transmission speed and pixel size.

[0039] The third aspect of the present invention provides an electronic device, comprising:

[0040] At least one processor; and,

[0041] A memory communicatively connected to the at least one processor; wherein,

[0042] The memory stores instructions that can be executed by the at least one processor, which, when executed by the at least one processor, enables the at least one processor to perform the traveling wave framing camera time characteristic calibration method as described in the first aspect of the present invention.

[0043] The fourth aspect of the present invention provides a computer-readable storage medium storing a computer program, which, when executed by a processor, implements the traveling wave framing camera time characteristic calibration method described in the first aspect of the present invention.

[0044] The present invention has the following beneficial effects:

[0045] The present invention provides a time characteristic calibration method for traveling-wave framing cameras. This method employs a technique of irradiating a microstrip with an adjustable optical path using a dual-beam irradiation system and acquiring static and dynamic spot images. By using the static image under DC voltage to perform spatial intensity correction on the dynamic image, the influence of non-uniformity in the spatial distribution of the laser spot on the calibration results can be effectively suppressed. This improves the accuracy of the gain attenuation curve fitting data without the need for additional inter-shot energy monitoring. Simultaneously, by acquiring multiple frames of images based on the variable optical path, and using these to calculate the gating pulse transmission speed, fit the gain attenuation curve, and finally solve for the exposure time, the complex calibration process required by existing technologies (which requires multiple discrete steps) is avoided. This calibration method can be completed in a single experimental setup by continuously adjusting the optical path and acquiring a series of images, improving calibration efficiency. By eliminating non-uniformity interference through spatial correction and combining it with its own optical path difference velocimetry, this method retains the high quantization accuracy advantage of the direct irradiation method while overcoming the technical problems of gain attenuation modulation and inaccurate pulse velocity measurement in existing methods. This achieves higher precision calibration of the exposure time and gain attenuation characteristics of framing cameras. Attached Figure Description

[0046] The above and other objects, features, and advantages of the present invention will become more apparent from the more detailed description of the embodiments of the invention in conjunction with the accompanying drawings. The drawings are provided to further illustrate the embodiments of the invention and form part of the specification. They are used together with the embodiments of the invention to explain the invention and do not constitute a limitation thereof. In the drawings, the same reference numerals generally represent the same parts or steps.

[0047] Figure 1 This is a schematic flowchart of a method for calibrating the time characteristics of a traveling wave framing camera provided in an exemplary embodiment of the present invention;

[0048] Figure 2 This is a schematic diagram of time characteristic calibration of a traveling wave framing camera provided in an exemplary embodiment of the present invention;

[0049] Figure 3 This is a schematic diagram of the optical path structure for calibrating the time characteristics of a traveling wave framing camera provided in an exemplary embodiment of the present invention;

[0050] Figure 4 This is a schematic diagram of a first spot image provided in an exemplary embodiment of the present invention;

[0051] Figure 5 This is a schematic diagram of a second light spot image provided in an exemplary embodiment of the present invention;

[0052] Figure 6 This is a schematic diagram of a grayscale curve provided in an exemplary embodiment of the present invention;

[0053] Figure 7This is a schematic diagram of the structure of an application embodiment of the electronic device of the present invention. Detailed Implementation

[0054] The present invention will be further described below with reference to the embodiments shown in the accompanying drawings. Obviously, the described embodiments are merely some embodiments of the present invention, and not all embodiments of the present invention. It should be understood that the present invention is not limited to the exemplary embodiments described herein.

[0055] It should be noted that, unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps described in these embodiments do not limit the scope of the invention.

[0056] Those skilled in the art will understand that the terms "first," "second," etc., in the embodiments of the present invention are only used to distinguish different steps, devices, or modules, and do not represent any specific technical meaning, nor do they indicate a necessary logical order between them.

[0057] It should also be understood that in the embodiments of the present invention, "multiple" can refer to two or more, and "at least one" can refer to one, two or more.

[0058] It should also be understood that any component, data or structure mentioned in the embodiments of the present invention can generally be understood as one or more unless explicitly defined or given contrary instructions in the context.

[0059] Furthermore, the term "and / or" in this invention is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, the character " / " in this invention generally indicates that the preceding and following related objects have an "or" relationship.

[0060] It should also be understood that the description of the various embodiments in this invention emphasizes the differences between the various embodiments, and the similarities or similarities can be referred to each other. For the sake of brevity, they will not be described in detail.

[0061] At the same time, it should be understood that, for ease of description, the dimensions of the various parts shown in the accompanying drawings are not drawn according to actual scale.

[0062] The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the invention or its application or use.

[0063] Techniques, methods, and equipment known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and equipment should be considered part of the specification.

[0064] It should be noted that similar labels and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be discussed further in subsequent figures.

[0065] Example 1

[0066] Figure 1 This is a schematic flowchart of a method for calibrating the time characteristics of a traveling-wave framing camera according to an exemplary embodiment of the present invention. The method can be performed by a calibration device that integrates an optical system, an electronic control unit, and a signal processing module, typically deployed in an ultrafast optical diagnostic laboratory environment.

[0067] Specifically, refer to Figure 1 , Figure 2 and Figure 3 The method for calibrating the time characteristics of a traveling wave framing camera includes:

[0068] Step 100: Split the pulsed laser into a first beam and a second beam that irradiate the microstrip of the framing camera. The optical path of the second beam is adjustable. Specifically, this step aims to construct a dual-beam calibration optical path. A femtosecond laser is used as the pulsed laser source. The emitted short pulsed laser first passes through a polarization state adjustment unit to obtain the desired polarization state. The polarization-adjusted laser is then incident on a beam splitter, which splits it into a first beam and a second beam with a constant intensity ratio. The split first beam and second beam are then incident on their respective sets of reflectors. Through the optical path guidance effect of the reflectors, both beams are accurately incident on cylindrical mirrors. The cylindrical mirrors focus the two laser beams to form elongated strip-shaped light spots, the extension direction of which is consistent with the length direction of the framing camera microstrip. The second beam has a precision one-dimensional translation stage along its optical path. Two mirrors are fixedly mounted on the translation stage. The second beam is reflected by these two mirrors and then incident on the cylindrical mirror. By adjusting the spatial position of the precision one-dimensional translation stage, the propagation path length of the second beam after reflection by the mirrors can be changed, thereby achieving continuous adjustment of the optical path of the second beam.

[0069] Step 200: Acquire the first spot image of the microstrip under DC voltage, and the second spot image acquired at least two different optical paths corresponding to the second beam when the framing camera is driven by the gating pulse and synchronized with the pulsed laser; specifically, the acquisition process of the first spot image is as follows: the gating pulse is disconnected, and DC voltage is applied only to the microstrip of the framing camera, at which time the image intensifier is in static working mode. A single pulsed laser emission is triggered, and the spot image on the microstrip at this time is acquired. (See [reference needed]). Figure 4The image records the spatial intensity distribution of two elongated light spots without time gain modulation, serving as the first light spot image. The acquisition process for the second light spot image is as follows: a gating pulse is applied to the microstrip of the framing camera, and the triggering time of the gating pulse is synchronized with the emission time of the femtosecond laser by a delay generator. Then, the optical path adjustment device of the second beam is adjusted to be in at least two different preset positions, thereby generating at least two different optical path differences. Under each specific optical path difference, a synchronous triggering and image acquisition is performed to obtain an image containing the light spots formed by both the first and second beams, which is the second light spot image. (See [reference needed]). Figure 5 .

[0070] Step 300: Based on the first spot image, perform spatial light intensity correction on the grayscale distribution of the strip-shaped spots formed by the first beam and the second beam in the second spot image.

[0071] Specifically, the calibration in this step aims to eliminate the influence of the spatial intensity inhomogeneity of the laser spot itself on the measurement results. First, for example, ... Figure 4 The first spot image shown contains two spot regions corresponding to the first and second beams. Gray-scale integration is performed along a direction perpendicular to the microstrip length to obtain two static reference curves characterizing the spatial intensity distribution contours of the first and second beams, respectively. Then, for each frame acquired... Figure 5 The second spot image shown is used to perform lateral integration on the two spot regions respectively, resulting in two dynamic grayscale distribution curves corresponding to that frame. Finally, the dynamic distribution curve of the first beam obtained in each frame (different optical path) of the second spot image is divided by its corresponding static reference curve to obtain the corrected first stripe grayscale distribution; similarly, the dynamic distribution curve of the second beam is divided by its static reference curve to obtain the corrected second stripe grayscale distribution. This operation removes the modulation caused by uneven spatial intensity distribution, ensuring that the corrected grayscale distribution primarily reflects the signal gain change determined by the timing characteristics of the gating pulse.

[0072] Step 400: Based on the grayscale peak position of the strip-shaped light spot in the corrected second light spot image, calculate the transmission speed of the gating pulse on the microstrip, and based on the grayscale data of the corrected second light spot image, fit the gain attenuation curve of the framing camera along the microstrip direction; specifically, see... Figure 6As shown, for each frame of the corrected second spot image, curve fitting is performed on the grayscale distributions of the first and second stripe spots to determine the pixel positions corresponding to their respective grayscale peaks. Since the optical path change of the second beam is directly converted into the time difference between the arrival of the two beams in the microstrip, and the gating pulse propagates along the microstrip in the form of a traveling wave, this time difference causes the peak position of the second stripe spot to shift relative to the peak position of the first stripe spot. By analyzing the pixel displacement between the two peak positions in at least two frames with different optical path differences, and combining this with the absolute time difference corresponding to the known optical path difference, the propagation speed of the gating pulse on the microstrip can be calculated. Simultaneously, to obtain the gain attenuation curve, the grayscale peak pixel positions of the first stripe spot in multiple frames are first averaged as the reference position for gain. Then, for the corrected grayscale distribution data of the second stripe spot, data alignment is performed using the peak position of each frame as the alignment point, and normalization is then applied. Finally, using the normalized gain at the reference position as a reference, the grayscale data of the second stripe after normalization of all frames are jointly fitted. An exponential decay model can be used to obtain the gain decay curve that characterizes the change of gain along the spatial position of the microstrip.

[0073] Step 500: Correct the grayscale distribution of the strip-shaped light spot in the second light spot image using the gain attenuation curve, and calculate the exposure time of the frame-shifting camera by combining the transmission speed and pixel size. Specifically, select one frame of the corrected second light spot image, and take the grayscale distribution of its first strip-shaped light spot as the object to be analyzed. Find the relative gain coefficient corresponding to each pixel position on the distribution according to the gain attenuation curve, and then divide the grayscale value of each pixel on the grayscale distribution to be analyzed by the relative gain coefficient of its position to eliminate the distortion of the light spot grayscale profile caused by the attenuation of the traveling wave gain along the microstrip, thereby obtaining the light spot grayscale distribution after gain attenuation correction, which is determined only by the gating pulse time gate width. Perform Gaussian function fitting based on the corrected distribution to solve for the pixel width corresponding to the full width at half maximum (FWHM). Multiply the pixel width by the physical pixel size of the camera to obtain the equivalent spatial broadening length of the light spot grayscale distribution on the microstrip plane. Finally, divide the equivalent spatial length by the gating pulse transmission speed to obtain the exposure time of the frame-shifting camera.

[0074] As described above, the time characteristic calibration method for traveling-wave framing cameras provided by this invention employs a technique of irradiating a microstrip with adjustable optical path using a dual-beam irradiation method and acquiring static and dynamic spot images. It utilizes the static image under DC voltage to perform spatial intensity correction on the dynamic image, effectively suppressing the influence of non-uniformity in the spatial distribution of the laser spot on the calibration results. This improves the accuracy of the gain attenuation curve fitting data without requiring additional inter-shot energy monitoring. Simultaneously, by acquiring multiple frames of images based on the variable optical path and using these to calculate the gating pulse transmission speed, fit the gain attenuation curve, and finally solve for the exposure time, it avoids the complex calibration process required by existing technologies, which involves multiple discrete steps. This calibration method can be completed in a single experimental setup by continuously adjusting the optical path and acquiring a series of images, improving calibration efficiency. By eliminating non-uniformity interference through spatial correction and combining it with its own optical path difference velocimetry, this method retains the high quantization accuracy advantage of the direct irradiation method while overcoming the technical problems of gain attenuation modulation and inaccurate pulse velocity measurement in existing methods. This achieves higher precision calibration of the exposure time and gain attenuation characteristics of framing cameras.

[0075] Example 2

[0076] Based on the above embodiment 1, as an optional implementation, step 200 includes:

[0077] Step 210: Adjust the optical path of the second beam using an optical path adjustment device to create at least two different optical path differences relative to the first beam. Specifically, in the optical path of the second beam, two reflectors are fixed to a precision one-dimensional translation stage controlled manually or automatically. When the optical path needs to be changed, by selecting a target position, the translation stage moves the reflector assembly linearly along the beam propagation direction, sequentially positioning it to at least two different preset positions. This allows the second beam to generate at least two known and controllable optical path differences relative to the fixed first beam. This optical path difference is the time interval between the arrival of the two femtosecond laser pulses at the microstrip surface of the framing camera.

[0078] Step 220: Under each optical path difference, synchronize the triggering time of the gating pulse with the emission time of the pulsed laser. This step ensures that, under each set optical path difference condition, the exposure time of the framing camera is aligned with the arrival time of the laser pulse. This can be achieved through a synchronous trigger control system, using the internal clock or external synchronization signal of the femtosecond laser as the master clock source. A programmable delay generator receives the clock signal and generates two trigger signals with controllable delays. One trigger signal triggers the femtosecond laser emission pulse, while the other trigger signal is used to trigger the gating pulse drive circuit of the framing camera.

[0079] Step 230: At each synchronization trigger moment, acquire a frame image containing two spatially separated strip-shaped light spots formed by the first and second beams. Specifically, first, move the translation stage to the first target position to generate the first optical path difference. Then, the system issues a synchronization trigger command, and the framing camera, driven by a gating pulse, acquires and saves a frame image containing the two spatially separated strip-shaped light spots formed by the first and second beams at the current moment. Subsequently, the translation stage moves sequentially to the second, third, and up to the nth target position, repeating the synchronization trigger and image acquisition process at each position. Finally, an image sequence consisting of at least two frames is obtained, where each frame uniquely corresponds to an optical path difference.

[0080] This embodiment ensures that the multi-frame dynamic image data required for calibration has a consistent benchmark and clear physical correlation in terms of the generation mechanism, that is, the optical path difference is the only controlled variable, which improves the quality of the input data of the calibration method.

[0081] Example 3

[0082] Based on Embodiments 1 and 2 above, as an optional implementation, spatial intensity correction is performed on the grayscale distribution of the strip-shaped light spots formed by the first beam and the second beam in the second light spot image, based on the first light spot image, including:

[0083] Step 310: Based on the first light spot image, obtain the static light intensity distribution information of the two strip-shaped light spots formed by the first beam and the second beam; first, apply a DC voltage to the microstrip to obtain, as shown below. Figure 4 The image shown is a static image. For the first strip-shaped light spot formed by the first beam, within its covered area, the grayscale value at each pixel location is integrated along a direction perpendicular to the microstrip length, resulting in a grayscale value that varies with the position along the microstrip direction. The changing curve is denoted as Similarly, by integrating the second stripe-shaped light spot region in the same direction, a second static gray-level distribution curve is obtained, denoted as... . and The inherent spatial intensity non-uniformity distribution of the laser spot, caused by factors such as optical components and transmission path, is recorded under conditions without time modulation. Assuming the spatial distribution of the laser spot remains stable between firing cycles, the curve... and The mathematical form of this can be used as a correction function to correct the spatial light intensity non-uniformity of the corresponding light spot dynamic image data.

[0084] Step 320: Based on the second spot images under different optical path differences, obtain the dynamic light intensity distribution information of the two strip-shaped spots formed by the first beam and the second beam; First, as described in Example 2, by adjusting the reflector mounted on the precision one-dimensional translation stage, move the translation stage to the first preset position. This alters the optical path of the second beam, thereby introducing a specific optical path difference between the first and second beams, which corresponds to a fixed time interval. Keeping the calibrated gating pulse trigger delay setting unchanged, ensures that the camera gating gate is synchronized with the laser pulse. Under this configuration, trigger the acquisition of the first frame of dynamic image. Perform the integration operation in step 310 on the two strip-shaped light spots in this image to obtain the result at the current optical path difference. Two dynamic grayscale distribution curves under the given conditions: the curve of the first stripe-shaped light spot is denoted as... The curve of the second stripe-shaped light spot is denoted as .

[0085] Step 330: Correct the dynamic light intensity distribution information using the static light intensity distribution information to obtain the corrected grayscale distribution of the striped light spot; the specific implementation is as follows: For the dynamic distribution curve obtained under each optical path difference, correct it using the corresponding static correction function. That is, for the first beam, calculate the corrected grayscale distribution: For the second beam, calculate the corrected grayscale distribution: Then, each corrected distribution curve is fitted to determine its peak characteristics. Using the first set of data... For example, fitting The curve yields its vertex, which is the pixel position corresponding to the maximum grayscale value. and peak grayscale ; Fitting The curve obtains its vertex position. and peak Similarly, adjust the position of the translation stage to... Keeping the trigger delay setting unchanged, triggering and obtaining the image, processing the data yields... The same method can be used to obtain Group data.

[0086] This embodiment uses a static reference image to correct the spatial light intensity distribution of dynamic measurement data, eliminating the influence of spatial non-uniformity of the light spot. This ensures that the pixel displacement used to calculate the transmission speed and the grayscale data used to fit the gain attenuation curve can truly and accurately reflect the time and gain characteristics of the framing camera's gating pulse itself.

[0087] Example 4

[0088] Based on the above embodiments 1, 2, and 3, as an optional implementation, the transmission speed of the gating pulse on the microstrip is calculated according to the grayscale peak position of the strip-shaped light spot in the corrected second light spot image, including:

[0089] Step 410: Based on the second spot images acquired under different optical path differences, extract the gray peak pixel positions of the gray distribution of the first strip-shaped spot formed by the first beam after correction, and the gray peak pixel positions of the gray distribution of the second strip-shaped spot formed by the second beam.

[0090] Step 420: Based on the pixel displacement of the grayscale peak pixel position of the second stripe spot relative to the grayscale peak pixel position of the first stripe spot under at least two different optical path differences, calculate the propagation speed of the gating pulse along the microstrip length direction; specifically, randomly select two sets of data. and The transmission speed of the gating pulse is calculated, and the expression is:

[0091]

[0092] In the formula, This indicates the propagation speed of the gating pulse along the length of the microstrip, measured in picoseconds per micrometer. Indicates the first The position of the precision one-dimensional translation stage corresponding to the set of data, and the change in its value directly reflects the change in the optical path of the second beam; Indicates the first The precise one-dimensional translation stage position corresponding to the set of data; Indicates the first The position of the grayscale peak pixel in the first strip-shaped spot (corresponding to the first beam) in the data set; Indicates the first The position of the grayscale peak pixel in the second stripe spot (corresponding to the second beam) in the data set; Indicates the first The position of the grayscale peak pixel of the first stripe-shaped spot in the data set; Indicates the first The grayscale peak pixel position of the second stripe-shaped spot in the data set; calculate multiple sets of data. The transmission speed of the gating pulse on the microstrip of the stripe camera is then obtained by averaging the values. Indicates the speed of light propagation; This indicates the pixel size of the framing camera imaging system.

[0093] This embodiment eliminates the need for complex external measuring devices such as time-domain reflectometers, which may contain inherent errors, thus avoiding systematic errors caused by mismatch between the measuring tool and the calibration object. Finally, by averaging multiple sets of data, the accuracy and reliability of the transmission speed measurement results are improved.

[0094] Example 5

[0095] Based on the above embodiments 1, 2, 3, and 4, as an optional implementation, the gain attenuation curve of the framing camera along the microstrip direction is fitted based on the grayscale data of the corrected second spot image, including:

[0096] Step 430: Based on the grayscale peak pixel positions of the first stripe of light extracted under at least two different optical path differences, determine a reference pixel position; specifically, calculate the arithmetic mean of the peak positions of the first beam measured under different optical path differences, and use this as the reference pixel position of the gain attenuation curve; this is because the optical path of the first beam is fixed, and the time for its light pulse to reach the microstrip is constant, so the position of its peak on the image is mainly determined by the on-time of the gating pulse.

[0097] Step 440: Using the reference pixel position as a reference, normalize the corrected grayscale distribution data of the strip-shaped light spot corresponding to the second beam; the goal of this step is to uniformly convert the corrected grayscale distribution data obtained by the second beam under different optical path differences to the same reference.

[0098] First, spatial alignment is performed: Because the second beam's peak appears at different pixel positions on the microstrip due to changes in optical path during each experiment, the grayscale distribution data of the second beam obtained from each measurement needs to be translated along the spatial axis so that the peak points of each distribution are aligned with the reference pixel position. To eliminate the small random fluctuations in laser pulse energy between different experimental bursts and to unify the amplitude scale of all data, this step requires dividing each aligned grayscale distribution data of the second beam by the peak grayscale value of the correction spot formed by the first beam in the corresponding burst. The resulting data is a set of relative gain distribution data centered on the reference position and with a unified amplitude scale, reflecting the shape of gain decay along space as sampled at different time points.

[0099] Step 450: Perform curve fitting on the normalized grayscale distribution data to obtain the gain attenuation curve. Specifically, based on the typical physical mechanism of image intensifier gain attenuation, an exponential attenuation model is selected as the basis for fitting. The fitting process inputs all normalized relative gain distribution data, including the specific relative gain values ​​at the reference position and the complete spatial distribution shape, into the fitting algorithm. The algorithm optimizes the calculation to find an optimal exponential attenuation curve that best matches all the input actual observation data. Finally, the fitting algorithm outputs a smooth, continuous gain attenuation curve. This curve quantifies the attenuation rate and pattern of the gain as it propagates from the reference position along the microstrip to both sides.

[0100] This embodiment employs an exponential model consistent with physical mechanisms for global fitting, resulting in a gain attenuation curve that is not only highly accurate but also has a clear physical meaning. The entire process eliminates the need to assume an ideal uniform light spot or perform additional independent energy monitoring, thereby improving the accuracy, reliability, and operational efficiency of characteristic calibration.

[0101] Example 6

[0102] Based on the above embodiments 1, 2, 3, 4, and 5, as an optional implementation, gain attenuation correction is performed on the grayscale distribution of the strip-shaped light spot in the second light spot image using a gain attenuation curve, including:

[0103] Step 510: Select a frame from the second light spot image and use its corresponding corrected stripe-shaped light spot grayscale distribution as the grayscale distribution to be corrected. This step selects one frame as a representative from all dynamic image data acquired under different optical path difference conditions and for which spatial intensity correction has been completed. Specifically, a frame with a high signal-to-noise ratio and a complete and clear light spot shape can be selected. From this frame, extract the grayscale distribution of the stripe-shaped light spot formed by the first beam and after spatial intensity correction processing, as the target data to be corrected subsequently.

[0104] Step 520: Based on the position of each pixel in the grayscale distribution to be corrected, query and obtain the relative gain coefficient corresponding to each position from the gain attenuation curve; map the spatial position information of each pixel in the grayscale distribution selected in Step 510 to the gain attenuation curve. The gain attenuation curve is a function that defines the relative gain value of each point on the microstrip relative to the point of highest gain. For each pixel coordinate in the distribution to be corrected, based on its actual position on the microstrip, find and obtain a corresponding relative gain coefficient from the gain attenuation curve. This coefficient quantitatively characterizes the proportion by which the signal amplification capability decreases compared to the peak position at that specific position due to the attenuation of the gating pulse during propagation.

[0105] Step 530: Divide the gray value at each pixel location in the gray-scale distribution to be corrected by the relative gain coefficient corresponding to that location to obtain the corrected gray-scale distribution. Specifically, perform point-by-point calculations on the two sets of data that are already one-to-one with spatial locations: the original gray-scale values ​​to be corrected and the queried relative gain coefficients. Divide the original gray-scale value at each pixel location by its corresponding relative gain coefficient. Physically, this is equivalent to stripping and compensating for the intensity modulation caused by spatial gain attenuation in the signal. After this step, a new gray-scale distribution curve is obtained. This new curve no longer contains the distortion caused by the gain variation along the microstrip direction, and its shape characteristics will mainly reflect the pure time-gating effect of the gating pulse.

[0106] This embodiment eliminates the spatial modulation error in the intensity of the light spot image caused by the attenuation of the gating pulse gain with the propagation distance in a traveling wave framing camera by establishing the correspondence between the spatial location of image pixels and the physical model of gain attenuation and performing deterministic compensation.

[0107] Example 7

[0108] Based on the above embodiments 1, 2, 3, 4, 5, and 6, as an optional implementation method, the exposure time of the frame-splitting camera is calculated, including:

[0109] Step 540: Fit the corrected grayscale distribution with a Gaussian function to obtain the fitted Gaussian curve; in this step, the Gaussian function is preferred as the fitting model. After a short pulse light signal passes through a gate with a time response similar to a Gaussian shape, the recorded signal distribution also exhibits Gaussian characteristics.

[0110] Obtain the second spot image in the first... The coordinates of the position along the microstrip in this measurement Original grayscale distribution data And obtain the grayscale distribution under the reference state. With system gain decay curve The original grayscale is corrected to obtain the corrected grayscale distribution. :

[0111]

[0112] Then use the Gaussian function to... By fitting the data, a Gaussian curve representing the spatial broadening of the signal is obtained.

[0113] Step 550: Calculate the full width at half maximum (FWHM) of the fitted Gaussian curve and convert it to the corresponding pixel width. Specifically, the FWHM is defined as the full width corresponding to half the peak height of the curve, and is a general parameter for measuring the degree of temporal or spatial broadening. Based on the mathematical properties of the Gaussian function, this width value can be directly calculated from the fitted curve parameters. The calculated value is initially expressed in image pixels, quantifying the apparent broadening of the light spot signal on the image plane.

[0114] Step 560: Multiply the pixel width by the cell size to obtain the equivalent spatial broadening length corresponding to the corrected grayscale distribution on the microstrip. This step converts the pixel distance in the image into the actual spatial distance on the microstrip surface. This requires introducing a known calibration constant—the cell size, which represents the actual physical size corresponding to each pixel in the camera image. Multiplying the full width at half maximum (FWHM) value in pixels calculated in the previous step by the cell size yields the equivalent physical broadening length corresponding to the grayscale distribution of the light spot on the microstrip plane. This length has a clear physical meaning; it represents the spatial range swept by the wavefront of the gating pulse propagating on the microstrip during the on-time.

[0115] Step 570: Calculate the exposure time of the framing camera based on the equivalent spatial stretching length and transmission speed. This step utilizes the propagation speed of the gating pulse on the microstrip, which has already been measured. This speed represents the time required for the leading edge of the pulse wave to propagate a unit length on the microstrip to calculate the exposure time of the framing camera, and can be expressed as:

[0116]

[0117] In the formula, This indicates the final calibration exposure time of the split-frame camera, representing the width of the time window during which the image intensifier effectively collects light signals; This indicates the transmission speed of the gating pulse on the microstrip; This represents the average half-width at half-maximum of the grayscale distribution curve after correction of spot 1, characterizing the average level of spot spatial broadening under multiple sets of data; Indicates the pixel size of a frame-shift camera imaging system;

[0118] This embodiment extracts the temporal width features of the signal through Gaussian fitting and uses the pixel size and pulse propagation velocity calibrated by the system itself to convert the pixel width in the image into the final physical time. The entire calculation process is based on the data chain generated and calibrated by this method itself, without relying on external measurements or idealized assumptions, thus solving the systematic errors caused by parameter measurement separation or mismatch in existing methods. The final exposure time result directly and accurately reflects the temporal performance of the traveling wave framing camera under real working conditions, achieving an improvement in calibration accuracy and reliability.

[0119] Example 8

[0120] It should be understood that the time characteristic calibration method for traveling wave framing cameras described in the foregoing embodiments herein can also be similarly applied to the following traveling wave framing camera time characteristic calibration apparatus for similar extensions. For simplicity, it has not been described in detail.

[0121] Reference Figure 3 The device includes a femtosecond laser arranged along the optical path, an optical path beam splitting and adjustment unit, and a framing camera. The optical path beam splitting and adjustment unit is configured to split the pulsed laser into a first beam and a second beam, and adjust the optical path length of the second beam. The framing camera is configured to acquire images of the first and second light spots. It also includes:

[0122] The spatial light intensity correction module is configured to perform spatial light intensity correction on the grayscale distribution of the strip-shaped light spots formed by the first beam and the second beam in the second light spot image based on the first light spot image.

[0123] The gain attenuation curve fitting module is configured to calculate the transmission speed of the gating pulse on the microstrip based on the gray value peak position of the strip spot in the corrected second spot image, and to fit the gain attenuation curve of the frame-segmented camera along the microstrip direction based on the gray value data of the corrected second spot image.

[0124] The exposure time calculation module is configured to use the gain attenuation curve to correct the grayscale distribution of the strip-shaped light spots in the second light spot image, and calculate the exposure time of the frame camera by combining the transmission speed and pixel size.

[0125] like Figure 3 As shown, the device mainly includes a femtosecond laser, an optical path splitting and adjustment unit, a framing camera, and an integrated control and processing unit along the optical path. The femtosecond laser, as a pulsed laser source, provides calibration light pulses with ultra-short time widths. The optical path splitting and adjustment unit is the key optical component of the device, and its core functions include two aspects: First, by using built-in optical elements such as beam splitters, the incident pulsed laser is split into a first beam and a second beam with independent propagation directions according to a preset ratio; second, by integrating a high-reflectivity mirror group driven by a precision displacement stage in the second beam's optical path, the optical path of the second beam is continuously and adjustable, thereby controllably generating the optical path difference between the two beams. The framing camera is the object to be calibrated and also the image signal acquisition end. Under the unified command of the control unit, it can operate in two modes: one is a static mode, that is, when only a DC voltage is applied to the microstrip, it acquires the first spot image used for spatial light intensity correction; the other is a dynamic mode, that is, when it is driven by its own gating pulse and strictly synchronized with the femtosecond laser, it acquires a series of second spot images corresponding to different optical path differences.

[0126] The spatial intensity correction module receives a first spot image and multiple frames of second spot images captured by a framing camera. Its internal algorithm first performs a lateral integration on the two strip-shaped spot regions in the first spot image to generate their respective static intensity distribution templates. Then, the same integration operation is performed on each frame of the second spot image to obtain a dynamic intensity distribution. Finally, by dividing each dynamic distribution by its corresponding static template, the spatial intensity correction of the grayscale distribution of the strip-shaped spots in all second spot images is completed, outputting the corrected grayscale distribution dataset.

[0127] The gain attenuation curve fitting module takes the corrected grayscale distribution dataset as input. First, it extracts the grayscale peak pixel positions of the two strip-shaped spots in each frame image after correction using a curve fitting algorithm. Next, based on the pixel displacement relationship between the two peak positions under at least two different optical path differences, and the known physical quantity of the optical path difference, it calculates the transmission speed of the gating pulse on the microstrip. Simultaneously, this module executes another data processing path: it determines a reference point based on the average value of the peak position of the first spot in multiple measurements, then performs spatial alignment and normalization processing on the corrected data of the second spot, and finally uses a preset exponential attenuation model to perform joint curve fitting on all normalized data to generate a gain attenuation curve characterizing the spatial variation of gain along the microstrip.

[0128] The exposure time calculation module receives the transmission speed and gain attenuation curve from the previous module and selects the first frame of corrected spot grayscale distribution as the data to be corrected. Its internal processing flow involves pixel-by-pixel gain attenuation correction of the distribution to be corrected based on the gain attenuation curve, resulting in the final corrected grayscale distribution. Subsequently, a Gaussian function is fitted to this distribution, and the full width at half maximum (FWHM) and half height (WHM) pixel values ​​of the fitted curve are calculated. Finally, this pixel width is multiplied by the known pixel size to obtain the equivalent spatial length, which is then divided by the transmission speed to calculate the final exposure time of the framing camera.

[0129] Example 9

[0130] In addition, embodiments of the present invention also provide an electronic device, including:

[0131] At least one processor; and,

[0132] A memory communicatively connected to the at least one processor; wherein,

[0133] The memory stores instructions that can be executed by the at least one processor, which, when executed by the at least one processor, enables the at least one processor to perform the traveling wave framing camera time characteristic calibration method as described in the first aspect of the present invention.

[0134] Figure 7 This is a schematic diagram of the structure of an application embodiment of the electronic device of the present invention. Below, refer to... Figure 7 This describes an electronic device according to embodiments of the present invention. The electronic device may be either or both of a first device and a second device, or a standalone device independent of them, which may communicate with the first device and the second device to receive acquired input signals from them.

[0135] like Figure 7 As shown, the electronic device includes one or more processors and a memory. The processor may be a central processing unit (CPU) or other processing unit with data processing capabilities and / or instruction execution capabilities, and may control other components in the electronic device to perform desired functions. The memory may include one or more computer program products, which may include various forms of computer-readable storage media, such as volatile memory and / or non-volatile memory. The volatile memory may, for example, include random access memory (RAM) and / or cache memory. The non-volatile memory may, for example, include read-only memory (ROM), hard disk, flash memory, etc. One or more computer program instructions may be stored on the computer-readable storage medium, and the processor may execute the program instructions to implement the traveling wave framing camera time characteristic calibration method and / or other desired functions described in the various embodiments of the present invention above.

[0136] In one example, the electronic device may further include input and output devices, which are interconnected via a bus system and / or other forms of connection mechanisms (not shown). Furthermore, the input device may include, for example, a keyboard, a mouse, etc. The output device can output various information to the outside, including determined distance information, direction information, etc. The output device may include, for example, a display, a speaker, a printer, and a communication network and its connected remote output devices, etc.

[0137] Of course, for the sake of simplicity, Figure 7 Only some of the components of the electronic device relevant to the present invention are shown, omitting components such as buses, input / output interfaces, etc. In addition, the electronic device may include any other suitable components depending on the specific application.

[0138] In addition to the methods and devices described above, embodiments of the present invention may also be computer program products, wherein a program for implementing the time characteristic calibration method of a traveling wave framing camera is stored on the computer-readable storage medium, and the program for implementing the time characteristic calibration method of a traveling wave framing camera is executed by a processor to implement the steps of the time characteristic calibration method of a traveling wave framing camera described in various embodiments of the present invention.

[0139] The computer program product can be written in any combination of one or more programming languages ​​to perform the operations of the embodiments of the present invention. The programming languages ​​include object-oriented programming languages ​​such as Java and C++, as well as conventional procedural programming languages ​​such as C or similar languages. The program code can be executed entirely on the user's computing device, partially on the user's computing device, as a standalone software package, partially on the user's computing device and partially on a remote computing device, or entirely on a remote computing device or server.

[0140] Furthermore, embodiments of the present invention may also be computer-readable storage media storing computer program instructions thereon, which, when executed by a processor, cause the processor to perform the steps in the traveling wave framing camera time characteristic calibration method according to various embodiments of the present invention described in the foregoing portion of this specification.

[0141] The computer-readable storage medium may be any combination of one or more readable media. A readable medium may be a readable signal medium or a readable storage medium. A readable storage medium may be, for example, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination thereof. More specific examples of readable storage media (a non-exhaustive list) include: an electrical connection having one or more wires, a portable disk, a hard disk, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable compact disk read-only memory (CD-ROM), optical storage device, magnetic storage device, or any suitable combination thereof.

[0142] Those skilled in the art will understand that all or part of the steps of the above method embodiments can be implemented by hardware related to program instructions. The aforementioned program can be stored in a computer-readable storage medium. When the program is executed, it performs the steps of the above method embodiments. The aforementioned storage medium includes various media that can store program code, such as ROM, RAM, magnetic disk, or optical disk.

[0143] The basic principles of the present invention have been described above with reference to specific embodiments. However, it should be noted that the advantages, benefits, and effects mentioned in the present invention are merely examples and not limitations, and should not be considered as essential features of each embodiment of the present invention. Furthermore, the specific details of the invention described above are for illustrative and facilitative purposes only, and are not limitations. These details do not limit the present invention to the necessity of employing the specific details described above.

[0144] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For system embodiments, since they largely correspond to method embodiments, the description is relatively simple; relevant parts can be referred to the descriptions in the method embodiments.

[0145] The block diagrams of devices, apparatuses, devices, and systems involved in this invention are merely illustrative examples and are not intended to require or imply that they must be connected, arranged, or configured in the manner shown in the block diagrams. As those skilled in the art will recognize, these devices, apparatuses, devices, and systems can be connected, arranged, and configured in any manner. Words such as “comprising,” “including,” “having,” etc., are open-ended terms meaning “including but not limited to,” and are used interchangeably with them. The terms “or” and “and” as used herein refer to the terms “and / or,” and are used interchangeably with them unless the context clearly indicates otherwise. The term “such as” as used herein refers to the phrase “such as but not limited to,” and is used interchangeably with it.

[0146] The methods and apparatus of the present invention may be implemented in many ways. For example, they may be implemented by software, hardware, firmware, or any combination of software, hardware, and firmware. The above-described order of steps for the methods is for illustrative purposes only, and the steps of the methods of the present invention are not limited to the order specifically described above unless otherwise specifically stated. Furthermore, in some embodiments, the present invention may also be implemented as a program recorded on a recording medium, the program comprising machine-readable instructions for implementing the methods according to the present invention. Thus, the present invention also covers recording media storing programs for performing the methods according to the present invention.

[0147] It should also be noted that in the apparatus, device, and method of the present invention, the components or steps can be disassembled and / or recombined. These disassemblies and / or recombinations should be considered as equivalent solutions of the present invention.

[0148] The above description of aspects of the invention is provided to enable any person skilled in the art to make or use the invention. Various modifications to these aspects will be readily apparent to those skilled in the art, and the general principles defined herein can be applied to other aspects without departing from the scope of the invention. Therefore, the invention is not intended to be limited to the aspects shown herein, but rather to be carried out within the widest scope consistent with the principles and novel features of the invention herein.

[0149] The above description has been given for purposes of illustration and description. Furthermore, this description is not intended to limit the embodiments of the invention to the forms described herein. Although numerous exemplary aspects and embodiments have been discussed above, those skilled in the art will recognize certain variations, modifications, alterations, additions, and sub-combinations therein.

[0150] It should be noted that the order of the above embodiments of the present invention is merely for descriptive purposes and does not represent the superiority or inferiority of the embodiments. The processes depicted in the accompanying drawings do not necessarily require a specific or sequential order to achieve the desired result. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0151] The various embodiments in this specification are described in a progressive manner. The same or similar parts between the various embodiments can be referred to each other. Each embodiment focuses on describing the differences from other embodiments.

Claims

1. A method for calibrating the time characteristics of a traveling wave framing camera, characterized in that, The method includes: The pulsed laser beam is split into a first beam and a second beam that irradiate the microstrip of the framing camera, and the optical path of the second beam is adjustable. Acquire a first spot image of the microstrip under DC voltage, and a second spot image of the corresponding second beam acquired at least two different optical paths when the framing camera is driven by a gated pulse and synchronized with a pulsed laser. Based on the first light spot image, spatial light intensity correction is performed on the gray-level distribution of the strip-shaped light spots formed by the first beam and the second beam in the second light spot image. Based on the position of the grayscale peak of the strip-shaped spot in the corrected second spot image, the transmission speed of the gating pulse on the microstrip is calculated, and based on the grayscale data of the corrected second spot image, the gain attenuation curve of the frame-segmented camera along the microstrip direction is fitted. Gain attenuation correction is applied to the grayscale distribution of the strip-shaped light spots in the second light spot image using a gain attenuation curve. The exposure time of the frame-splitting camera is then calculated by combining the transmission speed and pixel size, including: The modified grayscale distribution is fitted with a Gaussian function to obtain the fitted Gaussian curve; Calculate the full width at half maximum (FWHM) of the fitted Gaussian curve and convert the FWHM to the corresponding pixel width; Multiplying the pixel width by the cell size yields the equivalent spatial broadening length corresponding to the corrected grayscale distribution on the microstrip. Based on the equivalent spatial spanning length and transmission speed, the exposure time of the frame-splitting camera is calculated, and its expression is as follows: In the formula, This indicates the final calibrated exposure time for the framing camera; This indicates the transmission speed of the gating pulse on the microstrip; This represents the average value of the full width at half maximum (FWHM) of the grayscale distribution curve after the second spot image has been corrected. This indicates the pixel size of the framing camera imaging system.

2. The method for calibrating the time characteristics of a traveling wave framing camera as described in claim 1, characterized in that, Acquiring second spot images at at least two different optical paths corresponding to the second beam when the framing camera is driven by a gated pulse and synchronized with a pulsed laser, including: The optical path of the second beam is adjusted using an optical path adjustment device, so that the second beam produces at least two different optical path differences relative to the first beam. For each optical path difference, the triggering time of the control gating pulse is synchronized with the emission time of the pulsed laser; At each synchronization trigger moment, a second spot image containing two spatially separated strip-shaped light spots formed by the first beam and the second beam is acquired; wherein, for each optical path difference, a second spot image is acquired, thereby obtaining at least two second spot images.

3. The method for calibrating the time characteristics of a traveling wave framing camera as described in claim 1, characterized in that, Based on the first light spot image, spatial intensity correction is performed on the grayscale distribution of the strip-shaped light spots formed by the first beam and the second beam in the second light spot image, including: Based on the first light spot image, obtain the static light intensity distribution information of the two strip-shaped light spots formed by the first beam and the second beam; Based on the second spot image under different optical path differences, the dynamic light intensity distribution information of the two strip-shaped spots formed by the first beam and the second beam is obtained; The static light intensity distribution information is used to correct the dynamic light intensity distribution information to obtain the corrected grayscale distribution of the strip-shaped light spot.

4. The method for calibrating the time characteristics of a traveling wave framing camera as described in claim 3, characterized in that, Based on the position of the grayscale peak of the strip-shaped spot in the corrected second spot image, the propagation speed of the gating pulse on the microstrip is calculated, including: Based on the second spot images acquired under different optical path differences, the gray peak pixel positions of the gray distribution of the first strip-shaped spot formed by the first beam after correction and the gray peak pixel positions of the gray distribution of the second strip-shaped spot formed by the second beam are extracted respectively. The propagation speed of the gating pulse along the microstrip length direction is calculated based on the pixel displacement of the grayscale peak pixel position of the second stripe spot relative to the grayscale peak pixel position of the first stripe spot under at least two different optical path differences.

5. The method for calibrating the time characteristics of a traveling wave framing camera as described in claim 4, characterized in that, Based on the grayscale data of the corrected second spot image, the gain attenuation curve of the framing camera along the microstrip direction is fitted, including: Based on the grayscale peak pixel positions of the first strip-shaped light spot extracted under at least two different optical path differences, a reference pixel position is determined. Based on the reference pixel position, the corrected grayscale distribution data of the strip-shaped light spot corresponding to the second beam is normalized. The gain attenuation curve is obtained by curve fitting of the normalized grayscale distribution data.

6. The method for calibrating the time characteristics of a traveling wave framing camera as described in any one of claims 1 to 5, characterized in that, Gain attenuation correction is applied to the grayscale distribution of the strip-shaped light spots in the second light spot image using a gain attenuation curve, including: Select a frame from the second spot image and use its corresponding corrected stripe spot grayscale distribution as the grayscale distribution to be corrected. Based on the position of each pixel in the grayscale distribution to be corrected, the relative gain coefficient corresponding to each position is obtained by querying the gain attenuation curve; The corrected grayscale distribution is obtained by dividing the grayscale value at each pixel location in the grayscale distribution to be corrected by the relative gain coefficient at that location.

7. A time characteristic calibration device for a traveling wave framing camera, characterized in that, The traveling-wave framing camera time characteristic calibration method according to any one of claims 1 to 6, the apparatus comprising a femtosecond laser arranged along the optical path direction, an optical path beam splitting and adjustment unit, and a framing camera, wherein the optical path beam splitting and adjustment unit is configured to split the pulsed laser into a first beam and a second beam, and adjust the optical path length of the second beam; the framing camera is configured to acquire a first spot image and a second spot image; and further comprising: The spatial light intensity correction module is configured to perform spatial light intensity correction on the grayscale distribution of the strip-shaped light spots formed by the first beam and the second beam in the second light spot image based on the first light spot image. The gain attenuation curve fitting module is configured to calculate the transmission speed of the gating pulse on the microstrip based on the gray value peak position of the strip spot in the corrected second spot image, and to fit the gain attenuation curve of the frame-segmented camera along the microstrip direction based on the gray value data of the corrected second spot image. The exposure time calculation module is configured to use the gain attenuation curve to correct the grayscale distribution of the strip-shaped light spots in the second light spot image, and calculate the exposure time of the frame camera by combining the transmission speed and pixel size.

8. An electronic device, characterized in that, include: At least one processor; and, A memory communicatively connected to the at least one processor; wherein, The memory stores instructions that can be executed by the at least one processor to enable the at least one processor to perform the traveling wave framing camera time characteristic calibration method as described in any one of claims 1 to 6.

9. A computer-readable storage medium storing a computer program, characterized in that, When the computer program is executed by the processor, it implements the time characteristic calibration method for a traveling wave framing camera as described in any one of claims 1 to 6.

Images