Laser scanning system

Abstract

A method of scanning a laser beam over a field of view and a corresponding system, the method comprising: providing a laser to generate a laser beam; rasterizing the laser beam over a first sub-region of the field of view; deflecting the laser beam to a second sub-region of the field of view; and rasterizing the laser beam over the second sub-region of the field of view; capturing image information generated by the laser beam so that, for each sub-region of the field of view, the rasterized laser beam defines a plurality of image segments; calculating an image correction for each segment and correcting the laser in accordance with the image correction calculated for the segment.

Description

Technical Field

[0001] The embodiments relate to a laser scanning system for an optical system, such as a microscope, laser lithography, laser writing, laser engraving, and a corresponding laser scanning method. Background Technology

[0002] In any system that manipulates light or other electromagnetic radiation, numerous factors limit its capabilities. For example, in optical systems, one of the most important factors is likely the variation in the refractive index of light at different locations within a sample. Other examples include optical distortions in optical components (laser scanning units or field curvatures). These variations can make it difficult to achieve optimal results in space and / or time.

[0003] The term "adaptive optics" is generally used to describe the use of one or more active optical elements to correct minute variations that affect the optical properties of a system. Typically, this involves determining the degree of optical aberration that needs to be corrected, calculating the correction value, and then applying the correction.

[0004] Different methods exist for determining the required correction. One example relies on wavefront detectors, but this is prone to inaccuracies due to out-of-focus light. With wavefront detectors, the levels of dark noise, background noise, and crosstalk between each detector in a two-dimensional array can limit the performance of such systems.

[0005] Many existing correction methods cannot dynamically adapt to sample distortion; they cannot dynamically address spatially varying aberrations unless the scan is paused or restricted to a fixed scan field. Summary of the Invention

[0006] One embodiment provides a method for scanning a laser beam across a field of view, the method comprising:

[0007] Provide a laser to generate the laser beam;

[0008] The laser beam is rasterized in the first sub-region of the field of view;

[0009] The laser beam is deflected to a second sub-region of the field of view;

[0010] The laser beam is rasterized in the second sub-region of the field of view; and

[0011] Image information generated by the laser beam is captured so that, for each sub-region of the field of view, the rasterized laser beam defines multiple image segments;

[0012] Image corrections are calculated for each segment, and corrections are applied to the laser based on the image corrections calculated for the segments.

[0013] Each segment may be subject to correction.

[0014] Each segment and each correction can be time-registered. Time registration can include the relative time at which the recorded segment was scanned. Relative time can establish a segment sequence so that when a corresponding segment is rasterized, the laser correction can be applied to that segment.

[0015] The method also includes the step of applying corrections when scanning the corresponding segment with a laser.

[0016] The field of view can be target-dependent. The method may include moving the target relative to one or more optical elements (e.g., rasterization mirrors). Alternatively or additionally, the method may include moving optical elements relative to the target. The optical elements may include objective lenses. The field of view can be defined as a given position of the target relative to the optical elements. Therefore, in embodiments, neither the target nor the optical elements are moved when scanning a segment.

[0017] The temporal correlation between image segments and corrections may lead to temporal multiplexing methods for correction. Using temporal multiplexing can help widen the effective field of view for a given target location. It can also help increase laser intensity. By segmenting the field of view, different corrections can be applied to different spatial regions at different times.

[0018] The embodiments may specify the application of different corrections for different optical characteristics of the system and / or different optical characteristics of the target.

[0019] Computational image correction may include deriving a wavefront mask. Each correction may include a corresponding wavefront mask.

[0020] Calculating image correction for each segment may include applying a wavefront probing loop based on iterative images. The loop may include a hill-climbing algorithm applied to the intensity measurement. The intensity of each segment can be measured. Calculating image correction may include identifying the Zernike pattern for each segment and deriving one or more wavefront masks based on the identified Zernike pattern.

[0021] Application correction may include adjusting the deformable mirror. The deformable mirror can be adjusted according to the corresponding wavefront mask.

[0022] The only applicable optical correction can be implemented through deformable mirrors.

[0023] Rasterizing a laser beam can include moving the laser beam in two directions. The laser beam can be moved in a first direction corresponding to the x-axis and a second direction corresponding to the y-axis. Movement of the laser beam in the x-axis direction may be faster than movement in the y-axis direction. In this embodiment, the x-axis and y-axis are orthogonal to each other and lie in the target plane. The x-axis and y-axis can be chosen arbitrarily because, in this embodiment, the optical properties of the system are identical in the target plane.

[0024] Deflecting the laser beam into a second sub-region of the field of view can include deflecting the laser beam in the direction of the y-axis.

[0025] The deformable mirror can be synchronized with the movement of the laser beam along the y-axis. Therefore, embodiments may not require a high-speed deformable mirror to achieve aberration correction at a video frame rate (approximately 20 frames / second, with a dwell time of approximately 5 microseconds). In one embodiment, the deformable mirror is capable of performing 200 waveform masks per second. The deformable mirror can have 30 to 50 actuators. In one embodiment, the deformable mirror can have approximately 40 actuators. Synchronization may include saving the captured image information along with the time of capture. Then, when the segment is rasterized, the laser can be corrected at the appropriate time to apply the correction to the image information corresponding to the segment. It should be understood that by comparing the relative timing of the image information corresponding to all segments, the system is able to determine the order and timing of each correction to the laser.

[0026] In this embodiment, an iterative method is used to calculate the image correction. The correction applied to the laser can be updated with each iteration.

[0027] Each sub-region can cover the same area of ​​the field of view. Alternatively, the first sub-region can cover an area of ​​the field of view that is different from that of the second sub-region.

[0028] Another embodiment provides a system for scanning a laser beam across a field of view, the system comprising:

[0029] A laser used to generate a laser beam;

[0030] A first movable deflector is used to rasterize the laser beam over a first sub-region of the field of view;

[0031] A second movable deflector is used to deflect the laser beam, so that the first movable deflector...

[0032] The second sub-region of the field of view is rasterized;

[0033] An image digitizer is used to digitize image information generated by the interaction of a laser beam with a target;

[0034] A computer processor is used to capture image information generated by an image digitizer so that, for each sub-region of the field of view, a rasterized laser beam defines multiple image segments.

[0035] The computer processor calculates image correction for each segment.

[0036] The system also includes optical correction elements for applying correction to the laser beam based on calculated image corrections.

[0037] The system may include three movable deflectors for rasterizing sub-regions. Each movable deflector may consist of three scanning mirrors. The system may include a rotating polygonal mirror and two current-reflecting mirrors. A first movable deflector for rasterizing the laser beam in a sub-region of the field of view may include a rotating polygonal mirror and a first current-reflecting mirror. A second movable deflector for deflecting the laser beam to rasterize a second sub-region of the field of view may include a second current-reflecting mirror.

[0038] The field of view can be relative to a target. The target can be movable relative to one or more optical elements (e.g., rasterization mirrors). Alternatively or additionally, the optical elements can be movable relative to the target. The optical elements may include objective lenses. The field of view can be defined for a given position of the target relative to the optical elements. Therefore, in an embodiment, neither the target nor the optical elements are moved when scanning a segment.

[0039] Rasterizing a laser beam can involve moving the laser beam in two directions. The laser beam can move in a first direction corresponding to the x-axis and a second direction corresponding to the y-axis. During rasterization, the laser beam may move faster in the x-axis direction than in the y-axis direction.

[0040] During rasterization, the rotating polygon mirror can move the laser beam along the x-axis, while the first current mirror can move the laser beam along the y-axis. The x-axis and y-axis can be orthogonal to each other.

[0041] Moving the second current reflector can deflect the laser beam along the y-axis, thereby deflecting the laser beam into the second sub-region of the field of view.

[0042] The processor can calculate image correction for each segment. Image correction can be the calculated wavefront mask.

[0043] The processor can apply timestamps to each segment and each correction.

[0044] The processor can perform corrections while the laser scans the corresponding segment.

[0045] The temporal correlation between image segments and corrections may lead to temporal multiplexing methods for correction. Using temporal multiplexing can help broaden the effective field of view for a given target location. By segmenting the field of view, different corrections can be applied to different spatial regions at different times.

[0046] The implementation examples may specify different corrections to be applied for different optical characteristics of the system.

[0047] Computational image correction may include deriving a wavefront mask. Each correction may include a corresponding wavefront mask.

[0048] The embodiments can improve imaging performance; for example, the point spread function, spatial bandwidth product, and / or fluorescence intensity can be improved compared to known devices without optical segmentation of the detection signal. Therefore, the embodiments are not limited by the sensitivity of the wavefront detector or the number of image separators.

[0049] For each segment, computational image correction may include applying a wavefront probing loop based on iterative images. The loop may include a hill-climbing algorithm. Computational image correction may include identifying a Zernike pattern for each segment and deriving one or more wavefront masks based on the identified Zernike patterns.

[0050] Optical correction elements may include deformable mirrors. These deformable mirrors can be adapted to be adjusted by a processor according to a corresponding wavefront mask.

[0051] The optical correction element may include a deformable mirror. The system may include only one deformable mirror or other adaptive optics elements. The deformable mirror may be a low-resolution deformable mirror. The deformable mirror may also be a high-speed deformable mirror. In one embodiment, the deformable mirror is adapted to realize 200 waveform masks per second. The deformable mirror may have 30 to 50 actuators. In one embodiment, the deformable mirror may have approximately 40 actuators.

[0052] The embodiments can expand the imaging field of view while fully or almost fully recovering the point spread function.

[0053] Optical correction elements may include digital micromirrors and / or spatial light modulators.

[0054] The deformable mirror can be synchronized with the movement of the laser beam along the y-axis. Alternatively, the deformable mirror can be synchronized with the movement along the x-axis. Therefore, the embodiment may not require a high-speed deformable mirror to achieve aberration correction at a video frame rate (approximately 20 frames per second, with a dwell time of approximately 5 microseconds).

[0055] Each sub-region can cover the same area of ​​the field of view. Alternatively, the first sub-region can cover an area of ​​the field of view that is different from that of the second sub-region.

[0056] Another embodiment includes a method for scanning a laser beam across a field of view, the method comprising the steps of:

[0057] The laser beam is sequentially scanned by a raster within multiple sub-regions of the field of view, wherein the sub-regions are arranged in the first direction of the field of view;

[0058] Multiple image segments are defined for each sub-region, wherein the image segments of a specific sub-region are arranged in a second direction perpendicular to the field of view of the first direction;

[0059] Image information for each image segment is captured, and this image information is associated with the illumination of the field of view by the laser beam;

[0060] Image correction is calculated for each segment, wherein the image correction is configured to correct the laser beam when the laser beam is subsequently scanned by a raster on the corresponding segment.

[0061] Another embodiment includes a system for scanning a laser across a field of view, the system comprising:

[0062] A laser used to generate a laser beam;

[0063] The first movable deflector is used for the grating scanning laser beam;

[0064] A second movable deflector is used to deflect the laser beam to sequentially raster scan multiple sub-regions of the field of view, wherein the sub-regions are arranged in a first direction of the field of view.

[0065] An image capturing device configured to capture image information for each image segment, said image information being associated with the illumination of the field of view by a laser beam.

[0066] The processor is configured as follows:

[0067] Multiple image segments are defined for each sub-region, wherein the image segments of a specific sub-region are arranged in a second direction perpendicular to the field of view of the first direction;

[0068] Image information for each image segment is captured, and this image information is associated with the illumination of the field of view by the laser beam;

[0069] Image correction is calculated for each segment, wherein the image correction is configured to correct the laser beam when the laser beam is subsequently scanned by a raster on the corresponding segment.

[0070] This embodiment can be modified to use an existing laser scanning system. Attached Figure Description

[0071] The embodiments will be further described below with reference to the accompanying drawings, wherein:

[0072] Figure 1 This is a schematic diagram of the optical elements of a laser scanning microscope according to one embodiment;

[0073] Figure 2 yes Figure 1 A schematic diagram of the electronic components of the laser scanning microscope shown;

[0074] Figure 3 It shows Figure 1 The image segmentation of the field of view from the laser scanning microscope is shown.

[0075] Figure 4 A laser scanning method according to one embodiment is shown;

[0076] Figure 5 The correlation between an image fragment and a wavefront mask according to one embodiment is shown;

[0077] Figure 6 It shows Figure 1 The field of view of the laser scanning microscope is further segmented as shown;

[0078] Figure 7 The display shows multiple segments and sub-regions of the field of view, as well as the wavefront mask calculated for each segment and sub-region;

[0079] Figure 8 The effects of different wavefront corrections on different segments are shown;

[0080] Figure 9A and 9B It showed the uncorrected ( Figure 9A ) and after correction ( Figure 9B The result of the photolithography process;

[0081] Figure 9C Showing Figure 9A and 9B The strength profile of a selected portion of the sample; and

[0082] Figure 10 The improvement in intensity profile and resolution is shown between the uncorrected and corrected images of the beads. Detailed Implementation

[0083] Figure 1A laser scanning microscope 10 is shown. The laser scanning microscope 10 is used to image the sample 12 on the sample stage 14 at the target location by guiding a laser beam through the microscope's optical elements onto the sample 12 and collecting image information using a photomultiplier tube 34. Although this embodiment utilizes a photomultiplier tube 34, it should be recognized that any other device that converts optical information into electronic information can be used alternatively.

[0084] As shown, the microscope 10 includes a laser 16 that generates a laser beam. A deformable mirror 18 is used to apply a wavefront mask to correct optical aberrations in the microscope 10, and to hold the sample 12 as a target and / or its surroundings during use. It should be understood that the present invention relates to adaptive optics, and aspects of embodiments known in the art of adaptive optics will not be described in detail herein.

[0085] The polygonal scanning mirror 22 is used to scan the laser beam in the following manner. Two current reflectors 26 and 28 are also used to change the position of the laser beam relative to the target 12. The y-axis current reflector 26 changes the orientation of the laser beam along the y-axis (perpendicular to...). Figure 1 The drawing plane), while the x-axis current reflector 28 changes the orientation of the laser beam on the x-axis (in and out). Figure 1 (The drawing plane).

[0086] In the illustrated embodiment, microscope 10 includes three sets of telescopic lenses 20, 24, and 30, which focus and guide the laser beam. Filter 32 (in this embodiment, a dichroic long-pass filter) reflects the emitted fluorescence signal onto photomultiplier tube 34. Objective lens 36 focuses the laser beam passing through the optical elements of microscope 10 onto target 12. Image information is then captured by photomultiplier tube 34.

[0087] It should be recognized that, Figure 1 The laser scanning microscope 10 shown is merely one example of the application of the invention. As will be appreciated, further embodiments are applied in other types of microscopes, and, as described below, in fields outside of microscopy.

[0088] Figure 2 The electronic components of microscope 10 are shown. A deformable mirror 18, a polygonal mirror 22, and current mirrors 26 and 28 are connected to a processor 40 (e.g., in the form of a personal computing unit). Processor 40 includes a central processing unit 42 connected to a clock 44. Processor 40 is connected to a storage device 46 for storing information. A photomultiplier tube 34 is connected to processor 40 such that image information captured by photomultiplier tube 34 can be processed by the processor and stored on storage device 46.

[0089] Figure 2The processor 40 and other electronic components depicted are shown only schematically. Thus, for example, the clock 44 may be provided as part of the central processing unit 42, or it may be provided separately. Furthermore, it should be appreciated that the processor 40 and storage device 46 may alternatively be connected to the microscope 10 via a network in separate locations, and, as a further example, may also be provided as cloud computing.

[0090] Clock 44 provides a timing mechanism that allows image information, the relative positions of polygonal mirror 22 and current reflectors 26 and 28, and the operation of deformable reflector 18 to be synchronized in the following manner.

[0091] Figure 3 The scanned image information representing a sub-region or portion 50 of the field of view provided by objective lens 36 is shown. As shown, portion 50 has an x-axis (horizontal) and a y-axis (vertical). A rotating polygonal mirror 22 scans the laser beam along the x-axis, and a y-axis current reflector 26 scans the laser beam along the y-axis. Therefore, the scanned image information of sub-region 50 includes multiple rows of scanned image information forming specific columns. Thus, through the combined action of the rotating polygonal mirror 22 and the y-axis current reflector 26, a raster scan of sub-region 50 is performed using laser light.

[0092] Then, embodiments of the invention define segments 52 of subregion 50 by grouping such scan lines together. Figure 3 In the illustrated embodiment, there are five segments 52A, 52B, 52C, 52D, and 52E. As shown, each segment 52 consists of multiple scan lines. For example, segment 52A is considered to be from line 1 to line 102, while segment 52E is considered to be from line 409 to line 512, with intermediate lines allocated to the remaining segments 52B, 52C, and 52D. Preferably, adjacent segments 52 are demarcated between adjacent lines—for example, segment 52A ends at line 102, while segment 52B begins at line 103, thus segment 52 covers the entire sub-region 50.

[0093] According to one embodiment, during the scanning process defining sub-region 50, the x-axis current reflector 28 remains stationary. However, once the scanning process reaches the bottom of the column of sub-region 50, the current reflector 28 moves the laser beam to an adjacent sub-region 50, and the laser beam then scans the adjacent sub-region, as will be described below. Figure 6 To provide a more detailed explanation. Figure 6 The diagram shows sub-regions 50A, 50B, and 50C, each with five segments from 52A(A) to 52F(C) – thus, in the diagram, a specific segment 52 is associated with a row and a column, and the value in parentheses represents a specific sub-region 50A-50C.

[0094] Figure 4 It shows the use of Figure 1 The scanning laser microscope 10 shown illustrates a scanning laser method 80. In the initial step, i.e., step 82, the sample is scanned with a laser beam, and the corresponding image information is stored in the storage device 46. During this step, the rotating polygonal mirror 22 and the current reflective mirrors 26 and 28 cooperate to scan the field of view provided by the objective lens 36 by scanning multiple adjacent columns, as described above.

[0095] In one embodiment, the field of view is defined by an objective lens 36 that focuses a laser beam onto sample 12. The field of view is provided for a given position of objective lens 36.

[0096] In the next step, step 84, each segment is defined. In this step, the number of scan lines assigned to a segment is determined. This step may also include determining the size of the potential field of view to be processed. The definition of the segment size will determine the relative velocity of the rotating polygon mirror 22 and the current reflectors 26 and 28. As the image information for each segment is digitized and stored, a timestamp provided by clock 44 will be stored for the segment. This allows for synchronization correction of each segment later.

[0097] It should be recognized that the size of the segment can be selected based on the optical characteristics of the target and / or system. In particular, the segment size can be varied to find the optimal correction for the field of view under consideration.

[0098] Therefore, the fragment size can be changed while rasterizing.

[0099] In step 86, processing of these fragments begins. This process starts with the first fragment and iteratively loads the next fragment until all fragments have been processed. In step 88, an index (in this case, intensity) is calculated, and in the following step 90, a hill-climbing algorithm is used to predict the wavefront. The hill-climbing is achieved by moving from low (Z4) to high (Z15) through the first 13 orders of the Zernike mode (excluding the tip, tilt, and piston) to identify the optimal Zernike mask set for each correction; at each step, the Zernike amplitude is incremented by 0.05 steps. The optimization takes into account the measured intensity (higher is better) but does not consider the gradient between each point (the difference between each measurement).

[0100] It should be recognized that the step size value can be changed to meet specific requirements.

[0101] In step 92, the Zernike mode amplitude is set. In step 94, a wavefront mask corresponding to the current segment is generated and stored in storage device 46. Therefore, calculating image correction for each segment involves applying a wavefront detection loop based on iterative images.

[0102] The process then returns to step 86, which considers the next segment, and repeats steps 88, 90, 92, and 94 to generate a wavefront mask for the next segment. In this way, a wavefront mask is generated for each segment.

[0103] During operation, the sample is continuously scanned. Therefore, when the processor determines that it is scanning a segment for which a wavefront mask has been previously generated and stored, the processor uses the wavefront mask to deform the deformable mirror, thereby applying the wavefront mask to correct the aberrations of that segment. Figure 5 As shown, wavefront masks 102A, 102B, 102C, 102D and 102E correspond to segments 52A, 52B, 52C, 52D and 52E, respectively.

[0104] In one embodiment, for each segment 52, the determined wavefront mask 102 is continuously updated during each scan. For example, the calculated wavefront mask 102 can be used to image segment 52 to produce output (e.g., output to a display or data storage). The newly acquired image of segment 52 can also be used to determine a new wavefront mask 102 (as described in the embodiments herein). Advantageously, the newly determined wavefront mask 102 can produce more accurate corrections because it is determined from images produced by earlier wavefront masks 102. This correction process can be performed during the imaging of sample 12—and it can be expected that, in most cases, the resulting images will be continuously improved as a result, although the improvement will be small for subsequent captures. Maximum effective correction can be obtained after multiple updates.

[0105] Figure 6 This shows the offset method of the scanned sub-region 50. The middle column corresponds to the above and Figure 3 The sub-region 50 is shown. The x-axis current mirror 28 is controlled to provide offsets along the x-axis, thereby defining different sub-regions 50. For example, sub-region 50A is offset relative to sub-region 50B, while sub-region 50B itself is offset relative to sub-region 50C. By applying a series of offsets, the system is able to advantageously expand the effective field of view of the scan. This is because different corrections are expected to be required in the field of view in the x-direction via the deformable mirror 18. This is similar to the different corrections required in the y-direction, however, the differences in the y-direction are naturally taken into account due to the grating scanning direction. Advantageously, by dividing the x-axis into different sub-regions 50, the field of view in both the x and y directions can be adequately corrected, thereby improving the imaging of the sample 12.

[0106] Figure 7An example of defining multiple sub-regions 50A-50J in a two-dimensional grid is shown. As shown, each sub-region 50A-50J comprises five segments 52, thus a total of fifty segments 52. Each segment 52 is shown with a calculated wavefront mask 102—it can be seen that each segment 52 has a unique wavefront mask 102, which will depend on the specific distortion in the corresponding imaging region.

[0107] Figure 7 An advantage is that a relatively large area is imageable (i.e., the field of view is relatively high), and the field of view is divided into discrete regions (i.e., segments 52) where unique wavefront masks 102 can be determined. An advantage of the invention may be the balance achieved between the number of determined wavefront masks 102 and the operating speed—for example, multiple discrete and unique wavefront masks 102 may advantageously allow for useful adaptive optics correction while maintaining a video-level frame rate (e.g., 20 frames per second).

[0108] like Figure 7 As shown, the size (i.e., the range of the field of view) of each segment 52 can vary. For example, segment 52A and segment 52B have different sizes. In the figure, the segment size differs in the x-direction, which essentially corresponds to the length of the line during raster scanning (i.e., laser scanning). In one embodiment, the number of lines in each segment 52 can also vary—that is, thereby changing the size in the y-direction. In one embodiment, variations in the length and number of lines can be applied to each segment 52, making the size of segment 52 variable in both the x and y directions.

[0109] Figure 8 Different improvements in measurements of the two fragments, 52TMy1 and TMy5, are shown. Here, a lower axial FWHM ("full width at half maximum") indicates better resolution, thus improving the results, while a higher fluorescence amplitude indicates improved results. For both TMy1 and TMy5, each measurement parameter was improved by comparing the wavefront-corrected ("RAO") versus non-wavefront-corrected ("No RAO") cases; however, the improvement was more pronounced in the case of TMy5. For the generation of Figure 8 For actual samples being measured, the wavefront correction required for TMy5 is more complex than that required for TMy1 due to more complex aberrations.

[0110] The implementation can operate at a speed comparable to video storage and playback (approximately 20 frames per second with a dwell time of approximately 5 microseconds) to perform wavefront optimization on selected segments, without slowing down the scan speed or reducing the region of interest.

[0111] Typically, when a sample 12 is imaged using a laser scanning microscope 10 without correction according to the embodiments described herein, optical and sample aberrations result in a non-isoplanar illumination field. The embodiments described herein can advantageously improve the illumination field to an ideal isoplanar illumination field—in particular, embodiments that continuously update the wavefront mask 102 can provide changes to the wavefront mask 102 that effectively iterate to an isoplanar illumination field.

[0112] Figure 10 The image shows the intensity map of the imaging bead suspended in the capillary. The top image shows the uncorrected image of the imaging bead, with the line contours in the right image corresponding to the lines shown in the left image. The bottom image shows the corrected image of the imaging bead, with the line contours in the right image corresponding to the lines shown in the left image. It can be seen that the peaks are more clearly defined in the corrected image, and the line contours do not contain erroneous peaks.

[0113] The effectiveness of an implementation (e.g., measured by signal strength improvement) may be related to the number of segments; the more segments, the greater the improvement in signal strength, up to a threshold beyond which the improvement becomes difficult to quantify with an increased number of segments. However, increasing the number of segments also increases the required processing resources, and the usability of the implementation may decrease if there is a lag between wavefront mask generation and retrieval, particularly when using scanning objectives. Therefore, for example, there may be a trade-off between the number of segments processed and the useful frame rate.

[0114] While embodiments relating to laser scanning microscopes have been described and discussed, it should be recognized that further embodiments can find applications outside the field of microscopy. For example, in the field of photolithography, laser scanning is used, and maximizing the power of the laser in the objective field of view during this process can be important. By applying different wavefront masks to different sub-regions or portions of the field of view, the embodiments can be used for such applications to expand the effective field of view of the objective and / or enhance the intensity of the laser. By expanding the effective field of view of the objective, the movement of the stage or objective may be reduced, potentially improving accuracy. By enhancing the intensity of the laser, photolithography or “laser writing” processes can be effectively applied to a wider range of materials and applications.

[0115] Figure 9A and 9B This image shows the result of a two-photon laser writing (i.e., photolithography) pattern formed in a fluorescent UV-curable adhesive within a glass capillary. The figure shows the cured adhesive under fluorescent conditions—the visible feature pairs correspond to the previous laser writing step. Figure 9A The image shows the laser writing result without wavefront correction, while Figure 9B The image shows the laser writing result after wavefront correction. Figure 9B The visible features indicate that the embodiment described herein, which uses a wavefront mask 102 to correct a segment 52 of the field of view during laser writing, corrects aberrations caused by the curved glass capillary (as well as...). Figure 9A (Compared to). The remaining fluorescence intensity on each spot indicates that the result is that the lithographic pattern does not elongate and the laser power distribution is more uniform. Figure 9C This shows an enlarged, uncorrected laser writing feature. Figure 9A ) and magnified corrected laser writing features ( Figure 9B The fluorescence intensity map shows that the corrected image exhibits significant improvements in both intensity and detail. It should be noted that wavefront correction was performed using a low-power laser to determine the wavefront mask 102 for each segment 52. Subsequently, laser writing was performed using a laser of sufficient power and the determined wavefront mask 102.

[0116] It should be recognized that further embodiments can be found in any system using a scanning laser. For example, in the fields of laser ablation and ranging.

[0117] It should be understood that if any prior art publications are referenced herein, such references do not constitute an acknowledgment that such publications form part of common general knowledge in the art, Australia, or any other country.

[0118] In the following claims and the preceding description of the invention, unless the context requires otherwise due to the language of expression or necessary implication, the word "comprising" or variations such as "comprising (verb)" or "comprising (noun)" are used in an inclusive sense, that is, explicitly indicating the presence of the stated feature but not excluding the presence or addition of further features in various embodiments. Similarly, the term "device" is used broadly to cover components provided as a whole, as well as examples of one or more of these components being provided separately from another component.

Claims

1. A method for scanning a laser beam across a field of view, the method comprising: Provide a laser to generate a laser beam; The laser beam is rasterized in the first sub-region of the field of view; Once the scanning process reaches the bottom of the column of the first sub-region, the laser beam is deflected to the second sub-region of the field of view that is adjacent to the first sub-region; and The laser beam is rasterized in the second sub-region of the field of view; and Image information generated by the laser beam is captured so that for each sub-region of the field of view, the rasterized laser beam defines multiple image segments, wherein the scanned image information of each of the first and second sub-regions includes multi-line scanned image information, and wherein the multi-line scanned image information is grouped to define image segments of the sub-region, each of the image segments consisting of multiple scan lines; Calculate image correction for each image segment, and apply correction to the laser based on the image correction calculated for the image segment; Specifically, a time stamp is applied to each correction and / or each image segment, and the temporal correlation between the image segment and the correction is provided, thereby providing a temporal multiplexing method for the correction.

2. The method of claim 1, further comprising temporal registration of each of the image segments and each of the corrections.

3. The method according to claim 1 or 2, further comprising the step of applying correction when scanning the corresponding image segment with a laser.

4. The method according to claim 1, wherein, The field of view is target-dependent, and the method further includes using an objective lens to focus the laser beam onto the target.

5. The method according to claim 1, wherein, Computational image correction includes deriving the wavefront mask.

6. The method according to claim 5, wherein, Each correction includes the corresponding wavefront mask.

7. The method according to claim 1, wherein, Calculating image correction for each image segment involves applying a wavefront detection loop based on iterative images.

8. The method according to claim 1, wherein, Application corrections include adjusting the deformable mirror.

9. The method according to claim 1, wherein, Rasterizing the laser beam involves moving the laser beam in a first direction corresponding to the x-axis and a second direction corresponding to the y-axis.

10. The method according to claim 9, wherein, The laser beam moves faster in the x-axis direction than it moves in the y-axis direction.

11. The method according to claim 9, wherein, Deflecting the laser beam into the second sub-region of the field of view includes deflecting the laser beam in the direction of the y-axis.

12. The method according to claim 8, wherein, The deformable mirror moves in sync with the laser beam along the y-axis.

13. The method according to claim 9, wherein, Each image fragment is associated with a unique portion of the field of view along the x and y axes, such that the image fragment substantially covers the field of view along the x and y axes.

14. The method according to claim 1, wherein, The first sub-region covers a different field of view than the second sub-region.

15. A system for scanning a laser across a field of view, the system comprising: A laser used to generate a laser beam; A first movable deflector is used to raster scan the laser beam over a first sub-region of the field of view. The first movable deflector includes a rotating polygonal mirror and a first current reflector, wherein the rotating polygonal mirror scans the laser beam on the x-axis and the first current reflector scans the laser beam on the y-axis. A second movable deflector is used to deflect the laser beam once the scanning process of the first movable deflector reaches the bottom of the column of the first sub-region, so that the first movable deflector grating scans the field of view of a second sub-region adjacent to the first sub-region, wherein the second movable deflector includes a second current reflector. An image digitizer, used to digitize image information generated by the interaction of a laser beam with a target; A computer processor is configured to capture image information generated by the image digitizer, such that for each sub-region of the field of view, a raster-scanned laser beam defines multiple image segments, wherein the scanned image information of each of the first and second sub-regions includes multi-line scanned image information, and wherein the multi-line scanned image information is grouped to define image segments of the sub-region, each image segment consisting of multiple scan lines. The computer processor calculates image correction for each image segment. The system also includes an optical correction element for applying correction to the laser beam based on a calculated image correction. The system is applicable to: Apply a timestamp to each correction and / or each image segment; and The temporal correlation between the image segment and the correction is provided, thereby providing a temporal multiplexing method for the correction.

16. The system according to claim 15, wherein, The movement of the second current reflector causes the laser beam to deflect along the y-axis, thereby deflecting the laser beam into the second sub-region of the field of view.

17. The system according to claim 15, wherein, The computer processor applies a timestamp to each image segment and each correction.

18. The system of claim 15, further comprising an objective lens for focusing the laser beam onto the target.

19. The system according to claim 15, wherein, The optical correction element is a deformable mirror.

20. The system according to claim 19, wherein, The deformable mirror moves synchronously with the laser beam along either the x-axis or the y-axis.

21. The system according to claim 15, wherein, The first sub-region covers a different field of view than the second sub-region.

22. A method for scanning a laser beam across a field of view, the method comprising the following steps: The laser beam is sequentially scanned by a raster within a plurality of sub-regions of the field of view, wherein the sub-regions are arranged in a first direction of the field of view; Multiple image segments are defined for each sub-region, wherein the image segments of the sub-region are arranged in a second direction perpendicular to the field of view of the first direction, and wherein the scan image information of each of the first and second sub-regions includes multiple lines of scan image information, and wherein the multiple lines of scan image information are grouped to define the image segments of the sub-region, each of the image segments consisting of multiple scan lines; Image information for each image segment is captured, and this image information is associated with the illumination of the field of view by the laser beam; Image correction is calculated for each image segment, wherein the image correction is configured to correct the laser beam when the laser beam is subsequently raster-scanned over the corresponding image segment. Apply a timestamp to each correction and / or each image segment; and The temporal correlation between the image segment and the correction is provided, thereby providing a temporal multiplexing method for the correction.

23. The method of claim 22, further comprising the step of: The laser beam is then scanned by a grating, and for each image segment, the calculated correction is applied to the laser beam using an optical correction element.

24. A system for scanning a laser across a field of view, the system comprising: A laser used to generate a laser beam; A first movable deflector is used for grating scanning of the laser beam. The first movable deflector includes a rotating polygonal mirror and a first current reflector, wherein the rotating polygonal mirror scans the laser beam on the x-axis and the first current reflector scans the laser beam on the y-axis. A second movable deflector is used to deflect the laser beam once the scanning process of the first movable deflector reaches the bottom of the column of the first sub-region, so that the first movable deflector scans a second sub-region adjacent to the first sub-region of the field of view, thereby sequentially raster scanning multiple sub-regions of the field of view, wherein the second movable deflector includes a second current reflector, wherein the sub-regions are arranged in a first direction of the field of view, wherein the scan image information of each of the first and second sub-regions includes multi-line scan image information, and wherein the multi-line scan image information is grouped to define image segments of the sub-region, each of the image segments consisting of multiple scan lines; An image capturing device configured to capture image information for each image segment, the image information being associated with the illumination of the field of view by the laser beam. Processor, the processor being configured to: Multiple image segments are defined for each sub-region, wherein the image segments of the sub-region are arranged in a second direction perpendicular to the field of view of the first direction; Image information for each image segment is captured, and this image information is associated with the illumination of the field of view by the laser beam; Image correction is calculated for each image segment, wherein the image correction is configured to correct the laser beam when the laser beam is subsequently raster-scanned over the corresponding image segment; Apply a timestamp to each correction and / or each image segment; and The temporal correlation between the image segment and the correction is provided, thereby providing a temporal multiplexing method for the correction.

25. The system of claim 24, further comprising an optical correction element for modifying the laser beam. in, During subsequent grating scanning of the laser beam, the processor is configured to control optical correction elements to apply calculated corrections to the laser beam for each image segment.

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