KR101038474B1 - 3-dimensional ultrafine structure fabrication system for auto focusing control and auto focusing control method thereof - Google Patents

Abstract

Disclosed is a three-dimensional microstructure manufacturing system with an auto focusing function. The three-dimensional microstructure manufacturing system of the present invention, the laser beam processing unit for changing and processing the path of the laser beam transmitted from the femtosecond laser, the objective lens for focusing and irradiating the processed laser beam, located on one surface of the glass substrate Photocurable resin that generates two-photon absorption by the laser beam irradiated through the objective lens to generate fluorescence, a moving stage for shifting the position of the glass substrate, a CCD camera for photographing a laser beam irradiated from the objective lens, And a control computer for setting the initial position, detecting the fluorescence from the image of the laser beam taken through the CCD camera while moving the moving stage in the Z-axis direction in which the objective lens is located, and automatically adjusting the position of the moving stage.

Femtosecond laser, two-photon absorption, fluorescence, auto focus

Description

3D microstructure fabrication system with autofocus control function and its autofocus control method {3-dimensional ultrafine structure fabrication system for auto focusing control and auto focusing control method

The present invention relates to a three-dimensional microstructure manufacturing system having an automatic focusing function and an automatic focusing method thereof.

Typical microstructure manufacturing systems produce microstructures of the desired shape by curing the photocurable resin using a laser beam. In this case, precision is required to manufacture a three-dimensional microstructure, and a method using a femtosecond laser beam has been developed for this purpose. Here, the femtosecond laser beam refers to a near infrared laser beam having a wavelength of 780 nm.

On the other hand, when the femtosecond laser beam is focused on the UV photocurable resin, a two-photon absorption phenomenon occurs only near the focal point of the focused femtosecond laser beam, thereby causing a photopolymerization phenomenon to the UV photocurable resin. In this case, the probability that two-photon absorption will occur is proportional to the square of the femtosecond laser beam intensity. The area that satisfies this condition is an area corresponding to the center of the focal point with the highest energy density in the focused femtosecond laser beam, which is a very narrow area. Thus, in the vicinity of the focal point, a shape having an accuracy of about 100 nm, which is a level below the diffraction limit of the femtosecond laser beam, can be produced.

On the other hand, when the photocurable resin is cured using a femtosecond laser, a photopolymerization phenomenon due to two-photon absorption occurs at the focal point where the laser beam is focused, and as a result, a microstructure of micrometer to nanometer can be obtained. In this case, the focal point where the laser beam is focused must be accurate to form a precise microstructure. Specifically, the femtosecond laser beam is focused by the objective lens to irradiate the photocurable resin. The photocurable resin is generally located on a glass substrate positioned under the objective lens. In this case, the focus of the laser beam must be located exactly at the boundary point of the glass substrate and the photocurable resin, that is, at the point where the photocurable resin starts from the glass substrate.

If the focal point of the femtosecond laser beam is present inside the glass substrate without being located at the boundary point between the glass substrate and the photocurable resin, or in the photocurable resin, it is impossible to obtain a microstructure having a desired shape. In order to solve this problem, conventionally, the height of the movable stage where the photocurable resin and the glass substrate are located is manually controlled by an operator to adjust the focus of the femtosecond laser beam to be located at the boundary point between the glass substrate and the photocurable resin. However, if there is not enough experience in focusing, it is difficult to precisely adjust the position of the focal point where the femtosecond laser beam is focused, and thus it is difficult to obtain precise results.

In addition, when the operator directly operates the movement stage in which the photocurable resin and the glass substrate are positioned, there is a problem in that the time for manufacturing the microstructure is long because the movement stage is operated over several stages.

The present invention is to solve the above-mentioned problems, when irradiating a laser beam using a femtosecond laser by detecting the fluorescence generated by the two-photon absorption of the photocurable resin, by adjusting the position of the moving stage to irradiate from the objective lens The present invention provides a three-dimensional microstructure manufacturing system capable of automatically adjusting the focus of a laser beam, and an automatic focus adjusting method thereof.

3D microstructure manufacturing system having an autofocus control function according to an embodiment of the present invention for achieving the above object, the femtosecond laser for irradiating a laser beam, the path of the laser beam transmitted from the femtosecond laser A laser beam processing unit for changing and processing, an objective lens for focusing and irradiating the laser beam processed by the laser beam processing unit, a glass substrate spaced apart from the lower portion of the objective lens, and positioned on one surface of the glass substrate, Photocurable resin that generates two-photon absorption by the laser beam irradiated through the objective lens to generate fluorescence, and positioned under the glass substrate to position the glass substrate at least one of X, Y, and Z axes Moving stage to move in the direction of the CCD camera to shoot the laser beam irradiated from the objective lens And setting the initial position of the moving stage such that the laser beam irradiated from the objective lens is positioned at a point except for the photocurable resin, and moving the moving stage in the Z-axis direction in which the objective lens is positioned, through the CCD camera. And a control computer that detects fluorescence from the captured image of the laser beam and automatically adjusts the position of the moving stage.

In the three-dimensional microstructure fabrication system, the laser beam processing unit, a first mirror for changing the path by reflecting the laser beam irradiated from the femtosecond laser, a first for controlling the output of the laser beam transmitted from the first mirror A half-wave plate, an isolator for preventing the laser beam output from the first half-wave plate from returning to the femtosecond laser, a polarizing beam splitter for transmitting P-polarized light and reflecting S-polarized light in the laser beam passing through the isolator, the isolator A second half-wave plate positioned between the polarization beam splitters for controlling output of a laser beam reflected through the polarization beam splitter, and a second mirror reflecting a laser beam reflected from the polarization beam splitter to change a path; A first laser beam for expanding the laser beam transmitted from the second mirror A long term, a galvano shutter that changes the path by reflecting the extended laser beam through the first laser beam expander, and acts as a switch, a second laser beam expander for expanding the laser beam transmitted through the galvano shutter, A pinhole positioned in the second laser beam expander and blocking the laser beam reflected through the galvano shutter when the galvano shutter changes its path; and reflecting the laser beam extended through the second laser beam expander. It may include a third mirror for changing the path and a fourth mirror for changing the path by reflecting the laser beam transmitted from the third mirror.

The control computer may calculate a subtraction result by subtracting a noise image value from an image value of a laser beam photographed by the CCD camera, and detect the fluorescence generated from the photocurable resin by the subtraction result value. .

In addition, the control computer calculates an image sum value by summing image values of the laser beam photographed by the CCD camera in units of movement distance of the movement stage, and integrates the image sum values in units of movement distance of the movement stage. Can be represented as a graph.

The control computer may automatically adjust the focus of the laser beam irradiated from the objective lens by adjusting the position of the moving stage according to the moving distance of the moving stage at the point where the slope is changed in the graph.

On the other hand, the automatic focus adjustment method of the three-dimensional microstructure manufacturing system according to an embodiment of the present invention, the first position for setting the initial position of the moving stage so that the laser beam to be irradiated from the objective lens is located at the point except the photocurable resin A second step of irradiating a laser beam through a femtosecond laser, a third step of changing and processing a path of the laser beam through a laser beam processing unit when the laser beam is transmitted from the femtosecond laser, and focusing the processed laser beam A fourth step of forming and irradiating the light, a fifth step of moving the moving stage in the Z-axis direction in which the objective lens is positioned, and photographing a laser beam emitted from the objective lens using a CCD camera while the moving stage is moved And detecting fluorescence from the image of the laser beam photographed by the CCD camera. And it includes a seventh step of automatically adjusting the position of the movable stage.

In this case, the seventh step may be performed by subtracting the noise image value from the image value of the laser beam photographed by the CCD camera to calculate a subtraction result value and the fluorescence generated from the photocurable resin by the subtraction result value. Detecting.

The seventh step may include calculating an image sum value by summing an image value of a laser beam photographed by the CCD camera in units of a movement distance of the movement stage, and adding the image sum value to a movement distance unit of the movement stage. Integrating with may further include the step of expressing the graph.

The seventh step may further include automatically adjusting the focus of the laser beam irradiated from the objective lens by adjusting the position of the moving stage according to the moving distance of the moving stage at the point where the slope is changed in the graph. can do.

According to the present invention, when irradiating a laser beam using a femtosecond laser by detecting the fluorescence generated by the two-photon absorption phenomenon of the photocurable resin, by adjusting the position of the moving stage on which the photocurable resin is placed to focus the laser beam automatically Can be adjusted. As a result, the focus of the laser beam focused through the objective lens can be accurately aligned to the boundary point of the photocurable resin, thereby forming a three-dimensional microstructure having a precise shape.

In addition, by automatically adjusting the focus of the laser beam, the time required for focusing can be shortened, and the operator does not need to perform a separate focusing process, thereby increasing convenience.

Hereinafter, with reference to the accompanying drawings will be described in detail the present invention.

1 is a view showing a three-dimensional microstructure manufacturing system according to an embodiment of the present invention. The three-dimensional microstructure manufacturing system 100 shown in FIG. 1 includes a femtosecond laser 110, a laser processing unit 120, an objective lens 130, a glass substrate 140, a photocurable resin 150, and a moving stage ( 160, a charge-coupled device (CCD) camera 170, and a control computer 180.

The femtosecond laser 110 irradiates a laser beam with a very short pulse width. Specifically, the laser beam irradiated through the femtosecond laser 110 has a high peak output since the pulse width is very short, such as 80 fs (100 fs = 100 × 10 ⁻¹⁵ s). Therefore, when irradiating the photocurable resin 150 near a high peak output, it can be locally hardened by the two-photon absorption phenomenon, and can harden the photocurable resin 150 to at least 100 nm accurately.

The laser processing unit 120 changes the path of the laser beam irradiated from the femtosecond laser 110, processes it, and transmits the processed laser beam to the objective lens 130. Specifically, the laser processing unit 120 includes the first to fourth mirrors 121a, 121b, 121c, and 121d, the first and second half-wave plates 123a and 123b, and the first and second laser beam expanders 127a, 127b), isolator 124, polarizing beam splitter 125, galvano shutter 126, and pinhole 128.

The first mirror 121a changes the path by reflecting the laser beam irradiated from the femtosecond laser 110. Accordingly, the laser beam irradiated from the femtosecond laser 110 may be transmitted to the first half-wave plate 123a through the first mirror 121a.

The first half-wave plate 123a controls the output of the laser beam transmitted from the first mirror 121a. The isolator 124 prevents the laser beam output from the first half-wave plate 123a back to the femtosecond laser 110.

Meanwhile, the polarization beam splitter 125 transmits P polarization and reflects S polarization in the laser beam passing through the isolator 124. The second half wave plate 123b is positioned between the isolator 124 and the polarization beam splitter 125 and controls the output of the laser beam reflected through the polarization beam splitter 125.

The second mirror 121b changes the path by reflecting the laser beam transmitted from the polarization beam splitter 125 and transmits it to the first laser beam expander 127a. Then, the first laser beam expander 127a expands the transmitted laser beam.

The galvano shutter 126 changes the path of the laser beam extended by the first laser beam expander 127a and serves as a switch for the laser beam. Then, the second laser beam expander 127b expands the laser beam transmitted from the galvano shutter 126. In this case, in the second laser beam expander 127b, a pinhole 128 may be positioned to block the laser beam transmitted from the galvano shutter 126 when the galvano shutter 126 changes the path. .

The third mirror 121c reflects the extended laser beam through the second laser beam expander 127b to change the path of the laser beam toward the fourth mirror 121d. In addition, the fourth mirror 121d reflects the transmitted laser beam to change the path of the laser beam toward the objective lens 130.

Meanwhile, the objective lens 130 irradiates the photocurable resin 150 with the laser beam processed through the laser beam processing unit 120, and focuses the laser beam to form a focal point during irradiation. In this case, in order to focus the laser beam and increase the photon density in the vicinity of the focus, it is preferable to use an objective lens having a high numerical aperture NA.

The glass substrate 140 is positioned below the objective lens 130 and is positioned at a distance from the objective lens 130. The photocurable resin 150 is positioned on one surface of the glass substrate 140, that is, the lower surface of the glass substrate 140 in the drawing.

The photocurable resin 150 has a characteristic in which a two-photon absorption phenomenon occurs due to the focus of a laser beam formed through the objective lens 130, thereby curing. In this case, when the two-photon absorption phenomenon occurs in the photocurable resin 150, the absorbed energy is released again within a short time to generate a photopolymerization phenomenon and fluorescence is generated.

The movement stage 160 is positioned below the glass substrate 140 and the photocurable resin 150 to position the glass substrate 140 and the photocurable resin 150 in at least one of an X axis, a Y axis, and a Z axis. Move in the direction of. That is, the position of the glass substrate 140 and the photocurable resin 150 may be changed according to the movement of the movement stage 160.

The CCD camera 170 photographs an area of the glass substrate 140 where the laser beam irradiated from the objective lens 130 arrives, and transmits an image of the laser beam to the control computer 180. Specifically, the CCD camera 170 captures the entire image of the laser beam such as fluorescence and the like generated on the glass substrate 140 by the laser beam irradiated from the objective lens 130 and records the value.

The control computer 180 controls the overall operation of the three-dimensional microstructure manufacturing system, and in particular, controls the auto focus function. Specifically, the control computer 180 sets the initial position of the moving stage 160 when a command for the auto focusing function is input.

The initial position of the movement stage 160 is a movement in which the laser beam irradiated from the objective lens 130 is positioned at a point excluding the photocurable resin 150, that is, a point not reaching the photocurable resin 150. It means the position of the stage 160. Therefore, the control computer 180 moves the moving stage 160 in the Z-axis direction opposite to the objective lens 130 before executing the auto focusing function so that the photocurable resin 150 is fixed from the objective lens 130. Spaced over distance. In this case, the separation distance may be a distance previously stored in the control computer 180, or may be adjusted by the operator.

In addition, the control computer 180 moves the moving stage 160 to set the corresponding position to "0" when the initial position is set, and controls the femtosecond laser 110 to irradiate the laser beam.

The control computer 180 detects fluorescence from the image of the laser beam photographed by the CCD camera 170 while moving the moving stage 160 in the Z-axis direction toward the objective lens 130. The related description will be described in more detail with reference to FIG. 2.

FIG. 2 is a schematic diagram illustrating an automatic focus adjustment method in the three-dimensional microstructure manufacturing system shown in FIG. 1. In FIG. 2, the objective lens 130 is spaced apart from the glass substrate 140 and the photocurable resin 150. And the glass substrate 140 and the photocurable resin 150 are located in the upper part of the movement stage 160, and the support stand 141a, 141b is provided in the lower both sides of the glass substrate 140. FIG.

As described above, as the initial position of the moving stage 160 is set, the focal point A of the laser beam irradiated from the objective lens 130 is at a position not reaching the photocurable resin 150. In this state, the moving stage 160 is moved in the Z-axis direction (arrow direction) in which the objective lens 130 is located so that the focal point A of the laser beam is moved toward the photocurable resin 150.

When the focus A of the laser beam irradiated from the objective lens 130 reaches the surface of the photocurable resin 150, that is, the boundary point between the glass substrate 140 and the photocurable resin 150 by the above process. In the photocurable resin 150, two-photon absorption occurs by the femtosecond laser beam, thereby causing fluorescence.

The control computer 180 subtracts the noise image value from the image value of the laser beam transmitted from the CCD camera 170 to calculate a subtraction result value. In this case, when the laser beam does not reach the photocurable resin 150, the photonization phenomenon and the fluorescence do not occur since the two-photon absorption phenomenon does not occur in the photocurable resin 150, so that the image value and the noise image value of the laser beam are not generated. Becomes the same.

On the other hand, when the focus of the laser beam irradiated from the objective lens 130 by the movement of the moving stage 160 reaches the photocurable resin 150, the photopolymerization phenomenon and the photopolymerization phenomenon by the two-photon absorption phenomenon of the photocurable resin 150 Fluorescence is generated. Accordingly, the image value of the laser beam transmitted through the CCD camera 170 is expressed as a value in which the noise image value and the fluorescence intensity value overlap. Therefore, the control computer 180 can subtract the noise image value from the image value of the laser beam, determine whether the fluorescence is detected from the subtraction result value, and detect the fluorescence intensity.

Meanwhile, the control computer 180 calculates an image sum value of the laser beam by summing image values of the laser beam photographed from the CCD camera 170 in units of moving distances of the movement stage 160. In addition, the calculated image sum of the laser beams is integrated in the moving distance unit of the moving stage 160 and represented as a graph. For example, when the movement stage 160 has moved 0.5 占 퐉 from the initial position set to "0", the image value of the laser beam is detected at the corresponding distance. When the moving stage 160 moves from 0.5 µm to 1 µm, the image value of the laser beam at the corresponding distance is detected. In this way, the image values of the laser beams at each moving distance are detected and summed, and then integrated and graphed. In this case, the integrated graph is a linear approximation, and a graph as shown in FIG. 3 can be obtained.

FIG. 3 is a graph illustrating a relationship between an image sum value of a laser beam and a moving distance of a moving stage in the three-dimensional microstructure manufacturing system shown in FIG. 1.

Referring to the graph shown in FIG. 3, the x-axis represents the moving distance of the moving stage, and the y-axis represents the image sum value of the laser beam. The point where the slope is changed in the graph is the fluorescence detection point (a). In this case, the fluorescence detection point (a) is the focus of the laser beam irradiated from the objective lens 130 by the movement of the moving stage 160 has reached the boundary point of the glass substrate 140 and the photocurable resin 150 Means that. That is, the fluorescence detection point (a) may be a point where photopolymerization and fluorescence are generated by two-photon absorption due to the focus of the laser beam reaching the photocurable resin 150. Thus, as the fluorescence is detected, the slope of the graph changes at the fluorescence detection point a.

The control computer 180 adjusts the position of the movement stage 160 according to the movement stage movement distance of the point (a) at which the slope changes in the graph. Specifically, the control computer 180 moves the movement stage 160 by the distance of the fluorescence detection point a whose slope has changed from the initial position of the movement stage 160 set to "0". Accordingly, the focal point of the laser beam irradiated from the objective lens 130 is precisely positioned at the boundary point of the photocurable resin 150, thereby making it possible to manufacture a precise microstructure.

FIG. 4 is a flowchart illustrating a method for adjusting auto focus of the 3D microstructure manufacturing system shown in FIG. 1.

Referring to FIG. 4, when the execution command for the autofocus control function is input (S210), the 3D microstructure manufacturing system 100 sets an initial position of the movement stage 160 (S220). Specifically, the initial position of the movement stage 160 is set so that the focal point of the laser beam to be irradiated from the objective lens 130 does not reach the photocurable resin 150.

Thereafter, when the initial position of the moving stage 160 is set, the laser beam is irradiated through the femtosecond laser 110 (S230). Then, the laser beam irradiated through the femtosecond laser 110 is transferred to the laser beam processing unit 120 to change the path and process the transfer to the object lens 130 (S240). Next, the 3D microstructure manufacturing system 100 forms and focuses the laser beam through the objective lens 130 (S250).

Meanwhile, the 3D microstructure manufacturing system 100 moves the moving stage 160 in the Z-axis direction in which the objective lens 130 is located, and uses the CCD camera 170 to emit a laser beam emitted from the objective lens 130. Shoot (S260). In detail, the CCD camera 170 may obtain an image of the laser beam by photographing an area of the glass substrate 140 where the laser beam irradiated from the objective lens 130 arrives.

Thereafter, the 3D microstructure manufacturing system 100 determines whether fluorescence is detected from the image of the laser beam photographed by the CCD camera 170 (S270), and if it is determined that fluorescence is not detected, the process continues to S260. Proceed.

On the other hand, when it is determined that fluorescence is detected, the focus of the laser beam is automatically adjusted by adjusting the position of the moving stage 160 (S280). Specifically, first, the noise image value is subtracted from the image value of the laser beam photographed by the CCD camera 160 to calculate a subtraction result value. The fluorescence generated from the photocurable resin 150 can be detected based on the subtracted result. That is, if the noise image value is subtracted from the image value of the laser beam and the value is “0”, the fluorescence is not detected. If any other value is calculated, the fluorescence is detected.

In addition, an image value of the laser beam is calculated by summing image values of the laser beam photographed by the CCD camera 160 in units of moving distances of the moving stage 160. Thereafter, the sum of the image values of the laser beams is integrated in the moving distance unit of the moving stage 160 to represent the graph. In this case, the integral graph can be expressed by linear approximation. In this graph, the point where the slope is changed may be determined as the fluorescence detection point, and the position of the movement stage 160 may be adjusted according to the movement distance of the movement stage 160 of the corresponding point. According to this method, the focus of the laser beam irradiated from the objective lens 130 can be automatically adjusted to be accurately positioned at the boundary point of the photocurable resin 150.

Although the above has been illustrated and described with respect to the preferred embodiments of the present invention, the present invention is not limited to the above-described specific embodiments, it is common in the technical field to which the invention belongs without departing from the spirit of the invention claimed in the claims. Various modifications can be made by those skilled in the art, and these modifications should not be individually understood from the technical spirit or the prospect of the present invention.

1 is a schematic diagram showing a three-dimensional microstructure manufacturing system having an automatic focusing function according to an embodiment of the present invention;

FIG. 2 is a schematic diagram illustrating an automatic focus adjusting method in the 3D microstructure manufacturing system shown in FIG. 1;

3 is a graph showing the relationship between the fluorescence intensity total value and the moving distance of the moving stage according to the auto focus in the three-dimensional microstructure manufacturing system shown in FIG. 1, and

FIG. 4 is a flowchart illustrating a method for adjusting auto focus of the 3D microstructure manufacturing system shown in FIG. 1.

Description of the Related Art [0002]

100: three-dimensional microstructure manufacturing system 110: femtosecond laser

120: laser processing unit 130: the objective lens

140 glass substrate 150 photocurable resin

160: moving stage 170: CCD camera

180: control computer

Claims (9)

delete A femtosecond laser for irradiating a laser beam; A laser beam processing unit for changing and processing a path of a laser beam transmitted from the femtosecond laser; An objective lens for focusing and irradiating the laser beam processed by the laser beam processing unit; A glass substrate spaced apart from the lower portion of the objective lens; A photocurable resin positioned on one surface of the glass substrate and generating two-photon absorption by a laser beam irradiated through the objective lens to generate fluorescence; A moving stage positioned below the glass substrate to move the position of the glass substrate in at least one of X, Y, and Z axes; A CCD camera for photographing a laser beam emitted from the objective lens; And The initial position of the moving stage is set so that the laser beam irradiated from the objective lens is positioned at the point except the photocurable resin, and the moving stage is photographed by the CCD camera while moving the moving stage in the Z-axis direction in which the objective lens is located. A control computer for detecting fluorescence from the image of the laser beam and automatically adjusting the position of the moving stage, The laser beam processing unit, A first mirror for changing a path by reflecting a laser beam emitted from the femtosecond laser; A first half-wave plate for controlling the output of the laser beam transmitted from the first mirror; An isolator for preventing the laser beam output from the first half-wave plate from returning to the femtosecond laser; A polarization beam splitter for transmitting P polarization and reflecting S polarization in the laser beam passing through the isolator; A second half-wave plate positioned between the isolator and the polarization beam splitter for controlling the output of the laser beam reflected through the polarization beam splitter; A second mirror for changing a path by reflecting a laser beam reflected from the polarization beam splitter; A first laser beam expander for expanding a laser beam transmitted from the second mirror; A galvano shutter that changes a path by reflecting the extended laser beam through the first laser beam expander and serves as a switch; A second laser beam expander for expanding a laser beam delivered through the galvano shutter; A pinhole positioned in the second laser beam expander and blocking the laser beam reflected through the galvano shutter when the galvano shutter changes its path; A third mirror reflecting a laser beam extended through the second laser beam expander to change a path; And And a fourth mirror configured to change a path by reflecting the laser beam transmitted from the third mirror. 3. The method of claim 2, The control computer, 3D microstructure, characterized by subtracting the noise image value from the image value of the laser beam taken by the CCD camera to calculate a subtraction result, and detecting the fluorescence generated from the photocurable resin by the subtraction result value Manufacturing system. The method of claim 3, The control computer, The image value of the laser beam photographed by the CCD camera is added to the moving distance unit of the moving stage to calculate an image sum value, and the integrated image is integrated to the moving distance unit of the moving stage to represent the graph. Three-dimensional microstructure manufacturing system. The method of claim 4, wherein The control computer, And adjusting the position of the moving stage according to the moving distance of the moving stage at the point where the tilt is changed in the graph to automatically adjust the focus of the laser beam irradiated from the objective lens. delete In the automatic focus adjustment method of the three-dimensional microstructure manufacturing system including a femtosecond laser, a laser beam processing unit, an objective lens, a glass substrate, a photocurable resin, a moving stage, a CCD camera and a control computer, A first step of setting an initial position of the moving stage such that a laser beam to be irradiated from the objective lens is positioned at a point except for the photocurable resin; Irradiating a laser beam through the femtosecond laser; A third step of changing and processing a path of the laser beam through the laser beam processing unit when a laser beam is transmitted from the femtosecond laser; A fourth step of forming and irradiating a focal point of the processed laser beam; A fifth step of moving the moving stage in the Z-axis direction in which the objective lens is located; A sixth step of photographing a laser beam emitted from the objective lens using the CCD camera while the moving stage is moved; And And detecting a fluorescence from the image of the laser beam photographed by the CCD camera to automatically adjust the position of the moving stage. The seventh step, Calculating a subtraction result by subtracting a noise image value from an image value of a laser beam photographed by the CCD camera; And Detecting the fluorescence generated from the photocurable resin by the subtraction result. The method of claim 7, wherein The seventh step, Calculating an image sum value by summing image values of a laser beam photographed by the CCD camera in units of a movement distance of the movement stage; And And integrating the sum of the image values in units of moving distances of the moving stages and expressing the summed values in a graph. The method of claim 8, The seventh step, And adjusting the focus of the laser beam irradiated from the objective lens by adjusting the position of the moving stage according to the moving distance of the moving stage at the point where the slope is changed in the graph. A method of auto focusing of a dimensional microstructure manufacturing system.

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