JPH0276574A - Laser processing method - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a laser processing method for processing a raw sample by irradiating a raw sample such as a living cell such as an egg or a microorganism with a laser beam. .

[Conventional technology]

Details of a conventional live cell laser perforation device are described in Japanese Patent Publication No. 7837/1983, and the objective lens of this device is shown in FIGS.

In the figure, the laser beam is focused at its narrowest focal plane, and samples such as living cells are processed at this point. If the laser beam incident on the objective lens is moved in the X direction and the focal plane is moved as shown in Figure 6, the sample will be processed linearly in the X direction, and if the sample is further moved in the Z direction, it will be processed into a planar shape. disconnected.

[Problem to be solved by the invention]

The above conventional technology does not take into account changes in the image, and when cutting live cells, the stage must be moved up and down (in two directions), which causes the microscope to go out of focus and the image to change. Therefore, it was difficult to observe cells during cutting. In addition, the objective lens of this device has two functions: one to focus the laser, and the other to obtain a magnified image of the sample.
If you move the sample in the Z direction like in the upper case, the focus will shift and you will lose its function as a microscope.

The cutting operation will be performed without being able to check the condition of the sample. Therefore, when cutting a raw sample, it often causes unnecessary damage and often causes the sample to die.

SUMMARY OF THE INVENTION An object of the present invention is to provide a laser processing method that allows a cutting operation to be performed while observing the state of cutting using an enlarged image of a microscope.

[Means to solve the problem]

The above object is achieved by gradually moving the lens constituting the beam expander in the optical axis direction and moving the focal point of the laser focused by the objective lens in the optical axis direction.

[For production]

When the lens constituting the beam expander is gradually moved in the optical axis direction, the laser focal point moves in the optical axis direction (Z direction) as shown in FIG. Therefore.

By scanning the scanner of the laser deflection device and at the same time gradually moving the lens 13' that makes up the expander, processing can be performed while keeping the distance between the sample and the objective lens constant, so the state of the sample can be checked using a microscope. You can process it while observing it.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1 to 4.

FIG. 1 shows the overall configuration, in which the beam of a laser 10 is adjusted by an optical interface 11, and then the direction of incidence on the objective lens 1 is determined by an optical path deflection device rL9, which is a part of the microscope 8. incident on . The ray →J incident on the objective lens l is narrowed down and irradiated onto the sample 3 fixed on the stage 6.

The microscope fj#, 8 includes a scanner controller 7 that controls the direction of incidence of the laser onto the objective lens l, a TV camera 16 that observes the specimen image, and a contour detector 17 that compares and detects the outline of the specimen and the laser irradiation point. is installed.

The first optical interface 11 includes a beam expander 12 that controls the position of the focal point in the Z direction of the laser focused by the objective lens l, and the lens 13' constituting the second beam expander 12 A lens movement device i14 that moves in the axial direction and a lens movement controller 15 that controls this lens movement device are installed. As shown in FIG. 2, the optical path deflection device 9 incorporates two mirrors 20, 20' and two scanners 19, 19' that control the angles of the respective mirrors. By rotating each mirror 20.
20' changes, and the optical path of the laser incident here can be deflected onto the surface of the sample 3 (in the XY force directions.Next, a detailed explanation of the beam expander 12 will be given using Fig. 3. In FIG. 3, the two lenses on the left are lenses 13, 13', and
Objective lens on the right! It is. Beam expander 1 in the figure
By moving the second lens 13' in the optical axis direction, the focal point of the beam focused by the objective lens l moves in the optical axis direction as indicated by Δl in the figure. Therefore, by utilizing this behavior, the distance between the sample and the objective lens 1 can be kept constant, that is, the sample can be cut while viewing an enlarged image of the sample.

Hereinafter, the operation of the present invention will be explained using FIGS. 1 to 4. As an example, a case will be described in which the mirror force shown in FIG. 2 is fixed and the mirror force is vibrated.

When you start cutting the sample, fix the mirror cutter shown in Figure 2.
Excite the mirror force. As a result, as shown in FIG. 2, the laser beam focused by the objective lens l moves back and forth on the sample surface in the direction of the arrow. In this case, the contour of the sample is detected by the contour detector 17, this signal is input to the scanner controller 7, and the rotation angle of the mirror is controlled to correspond to the width of the sample (W in FIG. 2). Simultaneously with this vibration of the scanner 9, as shown in FIG. 3, if the lens 13' of the beam expander is gradually moved in the optical axis direction, the sample is cut. In this case, the sample remains at a constant distance (constant working distance) with respect to the objective lens l, and the cutting operation can be performed while keeping the microscope image constant. Fourth
The figure shows a sample cut surface when a pulsed laser is used as the laser 10. The laser irradiation point is indicated by a circle, and cutting ends when the sample reaches the 1@ part (point A).

The ease with which a sample is cut depends on the physical properties of the sample, but if the sample is difficult to cut, the rotational speed of the scanner, the moving speed of the lens that makes up the beam expander, the laser output, and the pulse repetition frequency should be adjusted. In other words, the distance between the irradiation points in the X direction shown in Figure 4 depends on the rotational speed of the scanner and the pulse repetition frequency of the laser, and the distance in the two directions constitutes a beam expander. It depends on the moving speed of the lens 13' and the pulse frequency of the laser.The size of the irradiation point (circle in the fourth section) also depends on the laser output.

Therefore, the sample can be cut under optimal conditions by controlling the scanner controller 7, lens movement control, laser O output, pulse repetition frequency, etc. according to the physical properties of the sample, as shown at 18 in Figure 1. .

According to this embodiment, since the cutting operation can be performed while observing the state of cutting with an enlarged image of a microscope, unnecessary damage to the sample is not caused, and the death of the sample can be prevented.

〔Effect of the invention〕

According to the present invention, the focus of the laser beam can be moved while keeping the distance between the sample and the objective lens constant, so processing can be performed while observing the state of the sample with a microscope.

[Brief explanation of the drawing]

Fig. 1 is an overall configuration diagram of a laser processing device according to an embodiment of the present invention, Fig. 2 is an explanatory diagram of the optical path polarizer, Fig. 3 is an explanatory diagram of the behavior of the beam expander, and Fig. 4 is a sample during cutting. 5 and 6 are front views of the vicinity of the objective lens of the prior art. l... Objective lens, 6... Stage,
7. Strike/scanner controller, 9... Optical path deflection device, 12... Beam expander, 14... Bend lens movement device M, 15... Lens movement controller, 16... ...TV camera, 17...contour detector, 19...scanner, addition...

Claims (1)

[Claims] 1. In a laser processing method in which a laser beam is focused using a lens and is irradiated onto a sample such as a living cell to process the sample, the optical axis direction of the laser beam incident on the objective lens is deflected using a mirror, and at the same time, the distance between the lenses of a plurality of lenses constituting a beam expander installed between the mirror and the laser light source is relatively moved, and the beam is focused by an objective lens. A laser processing method characterized by cutting a sample by moving the focal point of a laser in the optical axis direction.