Short-pulse laser three-dimensional space scanning method based on electrically-controlled zoom device, system, and device

Abstract

Disclosed in the present invention are a short-pulse laser three-dimensional space scanning method based on an electrically-controlled zoom device, a system, and a device. The method comprises: S1, acquiring a driving signal applied to an electrically-controlled zoom device; S2, setting a trigger signal of pulse laser, and presetting an axial scanning range of a cutting beam; S3, placing a sample on a translatable stage, positioning a target cutting area, and setting a motion trajectory of the stage; and S4, synchronously outputting the trigger signal and the driving signal, and controlling the stage to translate along the motion trajectory to achieve three-dimensional space scanning. According to the present solution, rapid axial scanning is controlled by means of a dual-channel signal, expanding an axial machining range of cutting laser; three-dimensional space scanning is achieved by incorporating two-dimensional translation; and by cyclically setting a periodic delay, the axial position of a cutting beam is quickly changed during cutting, without the need to re-focus for different micro-area thicknesses of a sample, thereby greatly improving the laser scanning efficiency and accuracy.

Description

Short pulse laser three-dimensional space scanning method, system and equipment based on electronically controlled zoom device Technical Field

[0001] The present invention relates to the field of laser microdissection, and in particular to a short-pulse laser three-dimensional space scanning method, system and equipment based on an electrically controlled zoom device. Background Art

[0002] Rapid and efficient separation of target samples is the key to the application of laser microdissection technology in the field of molecular biology. Laser microdissection is a technology that uses a focused light beam to separate cell groups or single cells from tissue slices under a microscope. The existing laser microdissection method mainly moves the sample along a predetermined trajectory to achieve two-dimensional scanning and cutting. However, the two-dimensional scanning and cutting method cannot change the axial focus position of the laser beam at any time. Therefore, it is necessary to adjust the axial focus position of the laser beam according to the thickness of the slice before cutting. This method has extremely high requirements for the overall flatness of the sample. However, when processing the sample slices, it is necessary to manually embed, fix and slice the tissue blocks and attach the slices to a special membrane. In this process, due to manual operation or certain specific processing methods, the slices are often uneven. Therefore, without adjusting the axial position of the cutting spot, it is impossible to effectively cut the various areas of the sample slices with uneven thickness.

[0003] Therefore, precise positioning of the focal plane is crucial when focusing the laser beam onto the workpiece in high-quality micromachining. To improve the accuracy of laser cutting, the existing solutions are as follows: 1. Improve the convergence effect of the laser beam by tight focusing to obtain a sub-micron-sized spot, thereby ensuring the focusing effect within a certain axial range and improving the precision of sample cutting. However, this method is accompanied by a narrow depth of field, which will greatly reduce the cutting efficiency of the out-of-focus area, especially for samples with uneven thickness or uneven surface, the cutting efficiency is low, and the target micro-area cannot be separated quickly and efficiently; 2. By increasing the cutting energy or using repeated cutting, but this method has a certain impact on the cutting quality and cutting efficiency, and is prone to damage the sample; 3. By creating structured light, such as Bessel beams, the degrees of freedom can be significantly increased, but its side lobes will cause other defects, and the modulation flexibility of this method is low; 4. Some existing laser cutters use mechanical compensation to focus, for example: using a stepper motor to drive the zoom device to move, thereby achieving zoom, or moving and adjusting the axial position of the sample to adjust the focal length, but this type of method requires continuous adjustment according to the height difference of different areas of the sample, and the waiting time for mechanical adjustment is too long, the efficiency is low, and the accuracy is relatively poor.

[0004] Summary of the Invention

[0005] Therefore, in order to solve the above problems, the present invention discloses a short-pulse laser three-dimensional space scanning method, system and equipment based on an electrically controlled zoom device.

[0006] The present invention is achieved through the following technical solutions:

[0007] A short-pulse laser three-dimensional space scanning method based on an electrically controlled zoom device comprises the following steps:

[0008] S1: Obtaining the optical power change curve of the electronically controlled zoom device as a driving signal;

[0009] S2: Generate a synchronous square wave signal of the drive signal, and record the synchronous square wave signal as a first reference signal. Set a delay based on the first reference signal so that a phase difference is formed between the rising edge of each cycle of the trigger signal and the rising edge of the drive signal. The phase difference is used to correspond to different optical powers of the electronically controlled zoom device, thereby adjusting the focal position of the cutting beam and adjusting the axial scanning length of the cutting beam.

[0010] If the frequency of the trigger signal is the same as the frequency of the drive signal, a delay t is set at the rising edge of each signal cycle of the first reference signal to form a trigger signal;

[0011] If the frequency of the trigger signal is less than the frequency of the drive signal, a second reference signal is generated, the rising edge position of the second reference signal is consistent with the rising edge position of the first reference signal and has the same frequency as the trigger signal, and t is set at the rising edge of each signal cycle of the second reference signal to form a trigger signal;

[0012] S3: Locating a target cutting area of ​​the sample on the stage, and setting a motion trajectory of the stage according to the target cutting area;

[0013] S4: Synchronously output the trigger signal and the drive signal, control the emission of the pulsed laser through the trigger signal, form a cutting beam after focusing, and control the optical focal length change of the electrically controlled zoom device through the drive signal, so that the cutting beam contacts the sample and zooms quickly; at the same time, control the movement of the stage along the motion trajectory, so that the sample on the stage and the cutting beam move relative to each other, realizing three-dimensional space scanning.

[0014] Preferably, in step S2, two or more different delays t (t1, t2, t3, ...) are set in the trigger signal to form a delay group, and multiple identical delay groups are cyclically set so that the delay settings in the trigger signal change periodically.

[0015] Preferably, in step S2, the length of the delay set in each delay group in the trigger signal increases one by one.

[0016] Preferably, in step S2, a Labview program is written to control the waveform generator board to synchronously output the trigger signal and the drive signal, wherein the delay is configured by setting some high-level points at the rising edge of each signal cycle of the first reference signal / second reference signal to zero, and the automatic index tunnel is used to set the periodic delay to obtain the trigger signal.

[0017] The short pulse laser three-dimensional space scanning control system based on the electronically controlled zoom device includes:

[0018] A driving signal acquisition unit, used to acquire an optical power variation curve of the electrically controlled zoom device as a driving signal;

[0019] a trigger signal setting unit, configured to generate a synchronous square wave signal of the drive signal, record the synchronous square wave signal as a first reference signal, and set a delay based on the first reference signal so that a rising edge of each cycle of the trigger signal forms a phase difference with a rising edge of the drive signal, wherein the phase difference is used to adjust the focal position of the cutting beam and the axial scanning length of the cutting beam in response to different optical powers of the electronically controlled zoom device;

[0020] If the frequency of the trigger signal is the same as the frequency of the drive signal, a delay t is set at the rising edge of each signal cycle of the first reference signal to form a trigger signal;

[0021] If the frequency of the trigger signal is less than the frequency of the drive signal, a second reference signal is generated, the rising edge position of the second reference signal is consistent with the rising edge position of the first reference signal and has the same frequency as the trigger signal, and t is set at the rising edge of each signal cycle of the second reference signal to form a trigger signal;

[0022] An imaging unit, configured to locate a target cutting area of ​​the sample on the stage and set a motion trajectory of the stage according to the target cutting area;

[0023] The driving unit is used to synchronously output the trigger signal and the driving signal, control the emission of the pulsed laser through the trigger signal, form a cutting beam after focusing, and control the optical focal length change of the electronically controlled zoom device through the driving signal, so that the cutting beam contacts the sample and zooms rapidly; at the same time, control the movement of the stage along the motion trajectory, so that the sample on the stage and the cutting beam move relative to each other, thereby realizing three-dimensional spatial scanning.

[0024] Short pulse laser three-dimensional space scanning equipment based on electronically controlled zoom devices, including:

[0025] A pulse laser, for providing pulsed laser;

[0026] A beam shaping mechanism for shaping the pulsed laser into a parallel wide beam;

[0027] An axial scanning mechanism, used to receive the shaped light beam and adjust the optical focal length of the light beam to form a cutting beam for cutting the sample;

[0028] The stage translation mechanism includes a translatable stage for positioning the sample and translating it along a set trajectory;

[0029] The control mechanism includes the short pulse laser three-dimensional space scanning control system based on the electric-controlled zoom device as described above.

[0030] Preferably, the beam shaping mechanism includes a first convex lens, a second convex lens and an aperture which are sequentially arranged in the emission direction of the pulse laser.

[0031] Preferably, the axial scanning mechanism includes an electrically controlled zoom device, a 4f system and an objective lens. The electrically controlled zoom device is arranged opposite to the light beam shaped by the beam shaping module, and the electrically controlled zoom device is placed on a conjugate plane of the rear focal plane of the objective lens to form a zoom objective lens.

[0032] Preferably, the imaging unit includes an illumination unit for providing wide-field illumination and a signal detection unit for receiving light signals emitted by the sample and performing microscopic positioning of the sample, the illumination unit includes an illumination light source, a fifth convex lens, a first tube lens and a beam splitter; the signal detection unit includes a second tube lens and a camera, the light beam emitted by the illumination light source passes through the fifth convex lens and the first tube lens and is reflected by the beam splitter in the direction of the sample, and the light signal emitted by the sample passes through the beam splitter and the second tube lens and reaches the camera.

[0033] The beneficial effects of the technical solution of the present invention are mainly reflected in:

[0034] 1. The combination of an electrically controlled zoom device and laser microdissection expands the axial processing range of the cutting laser through rapid axial scanning, reduces the requirement for precise focus control, and controls the change in the axial position of the laser while scanning in a two-dimensional plane to achieve three-dimensional spatial scanning. It can achieve high-quality micro-area separation for tissue slices with different sub-region structures and height differences. It is suitable for samples with uneven thickness or uneven surface. It can effectively remove the target micro-area at any position without increasing the cutting energy, expanding the system depth of field. For tilted workpieces or tissue slices with low flatness, it can achieve efficient laser cutting without the need for additional focusing operations or mechanical movement, homogenize the cutting quality, and reduce the requirement for sample flatness.

[0035] 2. Set the trigger signal of the laser pulse with reference to the driving signal, and output the trigger signal and the driving signal synchronously. Control the axial scanning range of the cutting beam by setting an arbitrary delay in the trigger signal, and adjust the rising edge of the trigger signal in different cycles and the phase corresponding to the driving signal by setting the delay length in different cycles to achieve rapid zooming, thereby ensuring that the axial scanning range of the cutting beam changes rapidly during the cutting process. In addition, by cyclically setting the periodic delay, the axial cutting position of the laser can be quickly changed while scanning in two dimensions. Therefore, there is no need to refocus for different micro-area thicknesses of the sample, which greatly improves the efficiency and accuracy of laser scanning. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] FIG1 is a schematic diagram of a short-pulse laser three-dimensional space scanning system based on an electrically controlled zoom device;

[0037] FIG2 is a schematic diagram of obtaining a trigger signal through a drive signal, and a schematic diagram of the change in the axial length of the cutting beam under the control of the trigger signal (in this case, the frequency of the drive signal is greater than the frequency of the trigger signal);

[0038] FIG3 is a schematic diagram of obtaining a trigger signal through a drive signal, and a schematic diagram of the change in the axial length of the cutting beam under the control of the trigger signal (in this case, the frequency of the drive signal is equal to the frequency of the trigger signal);

[0039] FIG4 is a comparative diagram showing the effects of cutting different subregions of non-flat kidney slices using the existing scanning laser microdissection method without axial control and the short pulse laser three-dimensional spatial scanning method with an electronically controlled zoom device disclosed in the present invention;

[0040] The marks in the figure include: 101, pulse laser; 102, first convex lens; 103, second convex lens; 104, aperture; 105, electric-controlled zoom device; 106, reflector; 107, third convex lens; 108, fourth convex lens; 109, dichroic mirror; 110, objective lens; 111, stage; 112, illumination light source; 113, fifth convex lens; 114, first tube lens; 115, beam splitter; 116, second tube lens; 117, camera; 118, control mechanism; 119, drive signal; 120, first reference signal; 121, trigger signal; 122, second reference signal. DETAILED DESCRIPTION

[0041] To more clearly and in detail illustrate the objectives, advantages, and features of the present invention, the following non-limiting description of preferred embodiments is provided for illustration and explanation. This embodiment is merely a typical example of the application of the technical solution of the present invention. Any technical solution formed by equivalent substitution or equivalent transformation falls within the scope of protection claimed by the present invention.

[0042] It is also stated that in the description of the solution, the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply a ranking of importance, or to implicitly indicate the number of technical features shown. Therefore, features defined as "first" or "second" may explicitly or implicitly include one or more of such features. In the present invention, "plurality" means two or more, unless otherwise specifically defined.

[0043] The present invention discloses a short pulse laser three-dimensional space scanning method based on an electrically controlled zoom device, which is characterized by comprising the following steps:

[0044] S1: Acquire the optical power variation curve of the electrically controlled zoom device 105 as the driving signal 119 .

[0045] Among them, the optical focal length change curve is obtained by the selected electric-controlled zoom device 105. The optical focal length change curve is a curve of the optical focal length change of the electric-controlled zoom device 105 over time. The size of the optical focal length is related to the voltage amplitude applied to the electric-controlled zoom device 105. The optical focal length change period is related to the period of the applied signal change curve. During the specific operation process, the optical focal length change curve can be adjusted according to needs, which will not be elaborated here.

[0046] S2: Generate a synchronous square wave signal of the drive signal 119, and record the synchronous square wave signal as a first reference signal 120. Set a delay based on the first reference signal 120 so that a phase difference is formed between the rising edge of each cycle of the trigger signal 121 and the rising edge of the drive signal 119. The phase difference is used to correspond to different optical powers of the electronically controlled zoom device, thereby adjusting the focal position of the cutting beam and adjusting the axial scanning length of the cutting beam.

[0047] If the frequency of the trigger signal 121 is the same as the frequency of the drive signal 119 , a delay t is set at the rising edge of each signal cycle of the first reference signal 120 to form the trigger signal 121 ;

[0048] If the frequency of the trigger signal 121 is less than the frequency of the drive signal 119, a second reference signal 122 is generated. The rising edge position of the second reference signal 122 is consistent with the rising edge position of the first reference signal 120 and has the same frequency as the trigger signal 121. t is set at the rising edge of each signal cycle of the second reference signal 122 to form the trigger signal 121.

[0049] As shown in FIG2 , the frequency of the drive signal 119 applied to the electronically controlled zoom device 105 is inconsistent with the frequency of the trigger signal 121 applied to the pulsed laser 101. Therefore, it is necessary to first set a second reference signal 122 based on the first reference signal 120 to be consistent with the frequency of the trigger signal 121. The rising edge of the second reference signal 122 is aligned with the rising edge of the first reference signal 120. When generating the second reference signal 122, if the frequencies of the first reference signal 120 and the second reference signal 122 are non-integer, the rising edge of the second reference signal 122 is not aligned with the rising edge of the first reference signal 120 (in FIG2 , at the second T / 2 and fourth T / 2 positions of the second reference signal 122). The waveform can be generated only when the rising edge of the second reference signal 122 is aligned with the rising edge of the first reference signal 120. The frequency of the trigger signal 121 can be obtained from the pulsed laser 101 used, which will not be described in detail here. The trigger signal 121 is generated after a delay t is set based on the second reference signal 122.

[0050] In some embodiments, when the frequency of the drive signal 119 applied to the electric-controlled zoom device 105 is consistent with the frequency of the trigger signal 121 applied to the pulsed laser 101, there is no need to generate the second reference signal 122. As shown in Figure 3, since the frequencies of the drive signal 119 and the trigger signal 121 are consistent at this time, the first reference signal 120 and the second reference signal 122 are also consistent. Therefore, the delay can be set directly based on the first reference signal 120 to form the trigger signal 121.

[0051] Among them, different phases in the same cycle of the driving signal 119 apply different voltages to the electrically controlled variable focus device 105. Therefore, different phases in the same cycle of the driving signal 119 correspond to different optical powers of the variable focus device. As shown in FIG3 , in some embodiments, the optical power variation curve, that is, the driving signal 119, is δ(t)~sin(wt). At this time, the period of the driving signal 119 is T(1 / ω), and the optical power of the electrically controlled variable focus device 105 varies within T / 2, that is, the optical power varies from -δ to δ. By presetting a delay t at the rising edge of each cycle of the first reference signal 120 to form a trigger signal 121, the rising edge of each cycle of the trigger signal 121 can correspond to a different phase of the driving signal 119 according to the preset delay length, that is, The different optical powers of the variable focus device are used to adjust the focal position of the cutting beam and the axial scanning length of the cutting beam. When the rising edges of different cycles of the trigger signal 121 correspond to different phases of the drive signal 119 within T / 2, different voltages are applied to the electrically controlled variable focus device 105 according to the phases. Therefore, the optical power of the electrically controlled variable focus device 105 also corresponds to different points between -δ and δ. Since the range of variation of the optical power is limited, the axial scanning range of the cutting beam is also within a certain range. When the optical power is set to vary between -δ and δ, the axial scanning range of the cutting beam varies between -z and z. At this time, the relationship between the total scanning range of the cutting beam and the optical power of the electrically controlled variable focus device 105 is as follows:

[0052] Where: M is the system magnification; f0 is the focal length of the objective lens 110.

[0053] In some embodiments, in step S2, two or more different delays t (t1, t2, t3...) are set in the trigger signal 121 to form a delay group, and multiple identical delay groups are cyclically set so that the delay settings in the trigger signal 121 change periodically.

[0054] Among them, within the total scanning range of the cutting beam, a periodic delay is set so that the focal position of the cutting beam continuously changes during the cutting process, thereby ensuring that the axial cutting length of the cutting beam changes rapidly within the preset axial scanning range, which can adapt to the axial cutting length required by the sample in different areas, without the need to allocate delays by area, thereby improving work efficiency and cutting accuracy. As shown in Figure 3, in step S2, three different delays t (t1, t2, t3) are set as a delay group, and multiple identical delay groups (i.e., t1, t2, t3, t1, t2, t3, t1, t2, t3...) are repeatedly set in the trigger signal 121, so that the delay in the trigger signal 121 is periodically changed. Therefore, the axial scanning length of the cutting beam is periodically changed and can adapt to the axial cutting length required by the sample in different areas.

[0055] In a preferred embodiment, in step S2, the length of the delay set in each delay group in the trigger signal 121 increases one by one (i.e., t1 < t2 < t3...), showing a progressive change. As the delay length increases, the phase of the driving signal 119 corresponding to the rising edge of each cycle of the trigger signal 121 changes, and corresponding to the different optical focal lengths of the electrically controlled zoom device 105, the focal position of the cutting light beam also gradually progresses toward the direction of the sample, thereby enabling the cutting light beam to achieve step-by-step axial scanning; by rapidly repeating the step-by-step axial scanning, it is ensured that the cutting light beam can adapt to the height difference changes in different areas of the sample.

[0056] As shown in Figure 4, the existing scanning laser microdissection method without axial regulation and the short-pulse laser three-dimensional spatial scanning method of the electric-controlled variable focus device disclosed in the present invention are respectively used to perform laser cutting on different sub-regions of non-flat kidney slices, wherein the thickness of the sample at different positions is different. Through focal plane measurement, it is found that there is a certain height difference in the focal plane position required for the sample in different areas, and the height difference is greater than the Rayleigh length of the system used in the scanning laser microdissection method without axial regulation. Therefore, the power density of the cutting beam of this system at the defocused position is lower than the ablation threshold, and therefore rapid and effective resection cannot be achieved.

[0057] Among them, four positions in Figure 4(a) were selected (Figures 4(b)-4(e)), and at these positions, the existing scanning laser micro-cutting method without axial regulation and the short-pulse laser three-dimensional space scanning method of the electric-controlled zoom device 105 disclosed in the present invention were respectively used for cutting. Among them, at these positions, the target micro-area cut by the existing scanning laser micro-cutting method without axial regulation is located at the top, and the target micro-area cut by the short-pulse laser three-dimensional space scanning method of the electric-controlled zoom device disclosed in the present invention is located at the bottom; as shown in Figure 4(b), this position is in the in-focus position of the system used by the scanning laser micro-cutting method without axial regulation. At this time, both methods can cut the target micro-area with high cutting accuracy; as shown in Figures 4(c)-4(e) These positions are in the defocused position of the cutting beam in the scanning laser microcutting method without axial regulation. At this time, there is a focal plane difference between the cutting beam of the scanning laser microcutting method without axial regulation and these positions. The power density of the cutting beam is lower than the ablation threshold, so only black ablation marks are left. If complete cutting is to be achieved, the cutting energy must be increased or the focus must be adjusted in real time according to different areas of the sample. The target micro-area cut by the short-pulse laser three-dimensional spatial scanning method of the electric-controlled zoom device disclosed in the present invention can be completely removed, and since the axial cutting length of the cutting beam changes rapidly within the preset axial scanning range, it can adapt to the axial cutting length required by the sample in different areas, and there is no need to perform multiple focusing according to the height difference of different areas, thereby improving work efficiency and achieving higher cutting accuracy.

[0058] In some embodiments, in step S2, a Labview program is written to control the waveform generator board to synchronously output the trigger signal 121 and the drive signal 119, wherein the delay is configured by setting some high-level points at the rising edge of each signal cycle of the first reference signal 120 / the second reference signal 122 to zero, and controlling the length of the delay by setting the number of high-level points set to zero, and using the automatic index tunnel to set the periodic delay to obtain the trigger signal 121, wherein the method for creating the automatic index tunnel is a prior art and will not be elaborated here.

[0059] S3: Using optical microscopy to locate the target cutting area of ​​the sample on the stage 111, and setting the motion trajectory of the stage 111 according to the target cutting area;

[0060] Among them, the carrier 111 can be translated along the x-axis and y-axis directions of the plane on which it is located. In some embodiments, slide rails are respectively set along the x-axis and y-axis directions at the bottom of the carrier 111, and the system controls the movement of the carrier 111 according to a preset motion trajectory through a motor. This is existing technology and will not be elaborated here.

[0061] S4: Synchronously output the trigger signal 121 and the drive signal 119, control the emission of the pulsed laser through the trigger signal 121, form a cutting beam after focusing, and control the optical focal length change of the electric-controlled zoom device 105 through the drive signal 119, so that the cutting beam contacts the sample and zooms quickly; at the same time, control the movement of the stage 111 along the motion trajectory, so that the sample on the stage 111 and the cutting beam move relative to each other, realizing three-dimensional space scanning.

[0062] Among them, the axial scanning length of the cutting beam, that is, the scanning range of the cutting beam in the z-axis direction, is changed by adjusting the optical focal length of the electrically controlled zoom device 105, and at the same time, the stage 111 is controlled to translate along the x-axis and y-axis directions according to the preset motion trajectory to achieve three-dimensional space scanning.

[0063] The present invention also discloses a short pulse laser three-dimensional space scanning control system based on an electrically controlled zoom device, comprising:

[0064] A driving signal acquisition unit, used to acquire an optical power variation curve of the electrically controlled zoom device as a driving signal;

[0065] a trigger signal setting unit, configured to generate a synchronous square wave signal of the drive signal, record the synchronous square wave signal as a first reference signal 120, and set a delay based on the first reference signal 120 so that a phase difference is formed between the rising edge of each cycle of the trigger signal 121 and the rising edge of the drive signal 119. The phase difference is used to adjust the focal position of the cutting beam and the axial scanning length of the cutting beam corresponding to different optical powers of the electronically controlled zoom device 105;

[0066] If the frequency of the trigger signal 121 is the same as the frequency of the driving signal, a delay t is set at the rising edge of each signal cycle of the first reference signal 120 to form the trigger signal 121;

[0067] If the frequency of the trigger signal 121 is lower than the frequency of the drive signal, a second reference signal 122 is generated. The rising edge position of the second reference signal 122 is consistent with the rising edge position of the first reference signal 120 and has the same frequency as the trigger signal. t is set at the rising edge of each signal cycle of the second reference signal 122 to form a trigger signal.

[0068] An imaging unit, configured to locate a target cutting area of ​​the sample on the stage and set a motion trajectory of the stage according to the target cutting area;

[0069] The driving unit is used to synchronously output the trigger signal and the driving signal, control the emission of the pulsed laser through the trigger signal, form a cutting beam after focusing, and control the optical focal length change of the electronically controlled zoom device through the driving signal, so that the cutting beam contacts the sample and zooms rapidly; at the same time, control the movement of the stage along the motion trajectory, so that the sample on the stage and the cutting beam move relative to each other, thereby realizing three-dimensional spatial scanning.

[0070] The present invention also discloses a short-pulse laser three-dimensional space scanning device based on an electrically controlled zoom device, comprising:

[0071] Pulse laser 101, used to provide pulse laser;

[0072] A beam shaping mechanism for shaping the pulsed laser into a parallel wide beam;

[0073] An axial scanning mechanism, used to receive the shaped light beam and adjust the optical focal length of the light beam to form a cutting beam for cutting the sample;

[0074] The stage 111 translation mechanism includes a translational stage 111 for positioning the sample and translating it along a set trajectory;

[0075] The control mechanism 118 includes the short pulse laser three-dimensional space scanning control system based on the electric-controlled zoom device as described above.

[0076] In some embodiments, the beam shaping mechanism includes a first convex lens 102 , a second convex lens 103 and an aperture 104 which are sequentially arranged in the emission direction of the pulse laser 101 .

[0077] In some embodiments, the axial scanning mechanism includes an electrically controlled zoom device 105, a 4f system and an objective lens 110. The electrically controlled zoom device 105 is arranged opposite to the light beam shaped by the beam shaping module, and the electrically controlled zoom device 105 is placed on a conjugate plane of the rear focal plane of the objective lens 110 to form a zoom objective lens 110. As shown in Figure 1, the 4f system includes a third convex lens 107 and a fourth convex lens 108. A reflector 106 is arranged between the electrically controlled zoom device 105 and the 4f system. The reflector 106 changes the optical path direction of the light beam after zooming by the electrically controlled zoom device 105 so that it reaches the 4f system. A dichroic mirror 109 is arranged between the 4f system and the objective lens 110. The dichroic mirror 109 changes the optical path direction of the light beam emitted by the 4f system and reflects the light beam to the objective lens 110.

[0078] In some embodiments, the imaging unit includes an illumination unit for providing wide-field illumination and a signal detection unit for receiving light signals emitted by a sample and performing microscopic positioning of the sample. The illumination unit includes an illumination light source 112, a fifth convex lens 113, a first tube lens 114, and a beam splitter 115; the signal detection unit includes a second tube lens 116 and a camera 117. The light beam emitted by the illumination light source 112 passes through the fifth convex lens 113 and the first tube lens 114 and is reflected by the beam splitter 115 toward the direction of the sample. The light signal emitted by the sample passes through the beam splitter 115 and the second tube lens 116 and reaches the camera 117, thereby achieving microscopic positioning of the sample to be cut.

[0079] There are many implementation methods of the present invention, and all technical solutions formed by equivalent transformation or equivalent transformation fall within the protection scope of the present invention.

Claims

1. A short-pulse laser three-dimensional spatial scanning method based on an electronically controlled zoom device, characterized by: The following steps are involved: S1: Obtaining the optical power change curve of the electronically controlled zoom device as a driving signal; S2: Generate a synchronous square wave signal of the drive signal, and record the synchronous square wave signal as a first reference signal. Set a delay based on the first reference signal so that a phase difference is formed between the rising edge of each cycle of the trigger signal and the rising edge of the drive signal. The phase difference is used to correspond to different optical powers of the electronically controlled zoom device, thereby adjusting the focal position of the cutting beam and adjusting the axial scanning length of the cutting beam. If the frequency of the trigger signal is the same as the frequency of the drive signal, a delay t is set at the rising edge of each signal cycle of the first reference signal to form a trigger signal; If the frequency of the trigger signal is less than the frequency of the drive signal, a second reference signal is generated, the rising edge position of the second reference signal is consistent with the rising edge position of the first reference signal and has the same frequency as the trigger signal, and t is set at the rising edge of each signal cycle of the second reference signal to form a trigger signal; S3: Locating a target cutting area of ​​the sample on the stage, and setting a motion trajectory of the stage according to the target cutting area; S4: Synchronously output the trigger signal and the drive signal, control the emission of the pulsed laser through the trigger signal, form a cutting beam after focusing, and control the optical focal length change of the electrically controlled zoom device through the drive signal, so that the cutting beam contacts the sample and zooms quickly; at the same time, control the movement of the stage along the motion trajectory, so that the sample on the stage and the cutting beam move relative to each other, realizing three-dimensional space scanning.

2. The short-pulse laser three-dimensional space scanning method based on an electrically controlled zoom device according to claim 1, characterized in that: In step S2, two or more different delays t (t1, t2, t3, ...) are set in the trigger signal to form a delay group, and multiple identical delay groups are cyclically set so that the delay settings in the trigger signal change periodically.

3. The short-pulse laser three-dimensional space scanning method based on an electrically controlled zoom device according to claim 2, characterized in that: In step S2, the length of the delay set in each delay group in the trigger signal is increased one by one.

4. The short-pulse laser three-dimensional space scanning method based on an electronically controlled zoom device according to claim 2, characterized in that: In step S2, a Labview program is written to control the waveform generator board to synchronously output the trigger signal and the drive signal, wherein the delay is configured by setting some high-level points at the rising edge of each signal cycle of the first reference signal / second reference signal to zero, and using the automatic index tunnel to set the periodic delay to obtain the trigger signal.

5. A short-pulse laser three-dimensional spatial scanning control system based on an electronically controlled zoom device, characterized by: include: A driving signal acquisition unit, used to acquire an optical power variation curve of the electrically controlled zoom device as a driving signal; The trigger signal setting unit is used to generate a synchronous square wave signal of the drive signal, and record the synchronous square wave signal as a first reference signal, and set a delay based on the first reference signal so that the rising edge of each cycle of the trigger signal is aligned with the rising edge of the trigger signal. The rising edge of the driving signal forms a phase difference, and the phase difference is used to correspond to different optical powers of the electronically controlled zoom device, thereby adjusting the focal position of the cutting beam and adjusting the axial scanning length of the cutting beam; If the frequency of the trigger signal is the same as the frequency of the drive signal, a delay t is set at the rising edge of each signal cycle of the first reference signal to form a trigger signal; If the frequency of the trigger signal is less than the frequency of the drive signal, a second reference signal is generated, the rising edge position of the second reference signal is consistent with the rising edge position of the first reference signal and has the same frequency as the trigger signal, and t is set at the rising edge of each signal cycle of the second reference signal to form a trigger signal; An imaging unit, configured to locate a target cutting area of ​​the sample on the stage and set a motion trajectory of the stage according to the target cutting area; The driving unit is used to synchronously output the trigger signal and the driving signal, control the emission of the pulsed laser through the trigger signal, form a cutting beam after focusing, and control the optical focal length change of the electronically controlled zoom device through the driving signal, so that the cutting beam contacts the sample and zooms rapidly; at the same time, control the movement of the stage along the motion trajectory, so that the sample on the stage and the cutting beam move relative to each other, thereby realizing three-dimensional spatial scanning.

6. A short-pulse laser three-dimensional space scanning device based on an electronically controlled zoom device, characterized by: include: A pulse laser, for providing pulsed laser; A beam shaping mechanism for shaping the pulsed laser into a parallel wide beam; An axial scanning mechanism, used to receive the shaped light beam and adjust the optical focal length of the light beam to form a cutting beam for cutting the sample; The platform translation mechanism includes a platform that can be translated and can be translated according to the set motion trajectory; And the short pulse laser three-dimensional space scanning control system based on the electronically controlled zoom device as described in claim 5.

7. The short-pulse laser three-dimensional space scanning device based on an electrically controlled zoom device according to claim 6, characterized in that: The beam shaping mechanism includes a first convex lens, a second convex lens and an aperture which are sequentially arranged in the emission direction of the pulse laser.

8. The short-pulse laser three-dimensional space scanning device based on an electrically controlled zoom device according to claim 6, characterized in that: The axial scanning mechanism includes an electrically controlled zoom device, a 4f system and an objective lens. The electrically controlled zoom device is arranged opposite to the light beam shaped by the beam shaping module, and the electrically controlled zoom device is placed on a conjugate plane of the rear focal plane of the objective lens to form a zoom objective lens.

9. The short-pulse laser three-dimensional space scanning device based on an electrically controlled zoom device according to claim 8, characterized in that: The imaging unit includes an illumination unit for providing wide-field illumination and a signal detection unit for receiving light signals emitted by a sample and performing microscopic positioning on the sample. The illumination unit includes an illumination light source, a fifth convex lens, a first tube lens, and a beam splitter.

10. The short-pulse laser three-dimensional space scanning device based on an electrically controlled zoom device according to claim 9, characterized in that: The signal detection unit includes a second tube lens and a camera. The light beam emitted by the illumination light source passes through the fifth convex lens and the first tube lens and is reflected by the beam splitter toward the direction of the sample. The light signal emitted by the sample passes through the beam splitter and the second tube lens and reaches the camera.

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