JPH11142786A - Laser optical path distributing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the productivity by distributing laser light to more than one optical path and to facilitate the adjustment and maintenance of the optical axis. SOLUTION: This is a laser optical path distributing device which distributes incident laser light to optical paths, and equipped with an optical modulating element 14 which modulates the incident laser light by making different the angle of the wave front of projection laser light, a beam splitter 15 which distributes the laser light to two optical paths according to the angle of the wave front of the projection laser light modulated by the optical modulating element 14, and a control means 13 which controls the modulation signal of the optical modulating element 14 so that the angle of the wave front of the projection laser light distributed by 100% to one optical path (b) of the beam splitter 15 and the angle of the wave front of the projection laser light distributed by 100% to the other optical path (c) are alternated, and the incident laser light is switched on a time-division basis and taken out.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laser light path distribution device that distributes incident laser light to a plurality of light paths.

[0002]

2. Description of the Related Art FIG. 8 is a view for explaining a conventional example of a laser beam machining apparatus, where 81 is a light source, 82 is an optical modulator,
83 is a control device, 84 and 84 'are total reflection mirrors, 85 and 8
5 'is a light collector, 86 and 89 are magnetic disk substrates, 87,
90 is a substrate rotating mechanism, 88 and 91 are substrate moving mechanisms, 92
Denotes an optical system moving mechanism.

In FIG. 8, a light source 81 is a laser light oscillator that oscillates a laser light for processing.
Reference numeral 2 denotes an on / off (pulse modulation) laser light from the light source 81. Magnetic disk substrates 86, 89
Is a workpiece to be textured by a laser beam to form minute projections (bumps) on the surface. Substrate rotation mechanism 8
Reference numerals 7 and 90 denote mechanisms for holding and rotating the magnetic disk substrates 86 and 89, and substrate moving mechanisms 88 and 91 for moving the magnetic disk substrates 86 and 89 in the radial direction. Reference numeral 92 denotes a mechanism for moving an optical system including the total reflection mirror 84 and the light collector 85 between the processed portions of the magnetic disk substrates 86 and 89. The control device 83 controls the ON / OFF timing of the optical modulator 82, the substrate rotation mechanism 87,
It controls the number of rotations of 90, the moving positions of the substrate moving mechanisms 88 and 91, and the moving position of the optical system moving mechanism 92.

In the texture recording apparatus having the above-described configuration, the control device 83 controls the optical system moving mechanism 92 to process the magnetic disk substrate 86 or the magnetic disk substrate 89.
Positioning of the optical system composed of the total reflection mirror 84 and the condenser 85 in the processing part of the above, and control of the substrate moving mechanisms 88 and 91 to position the irradiation points of the laser light on the magnetic disk substrates 86 and 89, 87, 90 are controlled so that the magnetic disk substrates 86, 89 have a constant rotational speed (CAV).
Alternatively, it is driven to rotate (CLV) so that the linear velocity at the irradiation position of the laser beam becomes constant. Then, the optical modulator 82 is controlled to control the on / off timing of the laser light,
By irradiating through the optical system including the total reflection mirror 84 and the condenser 85, the surface of the magnetic disk substrates 86 and 89 is textured with minute projections.

In a conventional processing apparatus using laser light, a plurality of processing sections including magnetic disk substrates 86 and 89, substrate rotating mechanisms 87 and 90, and substrate moving mechanisms 88 and 91 are provided in parallel as described above, and an optical system is provided. The control of the moving mechanism 92 causes the optical system to repeatedly move between the positions 84 and 85 and the positions 84 'and 85' in the drawing to perform the processing continuously, so that the utilization rate of the processing laser light source is increased. To increase
I try to improve work efficiency. The moving optical system 9
2 may be omitted and the optical system may be fixed and the processing portion may be relatively moved (for example, see Japanese Patent Application Laid-Open No. 8-224677).

[0006]

However, the above-mentioned conventional apparatus has a low switching speed and moves a mirror and a processing table, so that it is inferior in positioning accuracy and reproducibility and is not suitable for high-precision processing. There is no problem. Therefore, in order to increase the productivity, for example, a configuration in which a semi-transparent mirror is attached at a position shown in FIG.

According to this configuration, the magnetic disk substrate 86, which has been processed by closing the shutter (not shown) in the optical path of the condenser 85, is removed from the processing table, and a new workpiece is processed. Concentrator 85 'while attaching to the worktable
By opening the shutter of the optical path, the magnetic disk substrate 89 as a workpiece can be processed. By repeating such an operation, it is possible to double the production amount without using a moving mechanism with one optical system. However, in the apparatus for improving productivity in this way, the utilization rate of the processing laser light source is reduced to １ ／, so that a light source whose operation cost is expensive such as a laser oscillator increases the processing cost. There's a problem.

In the texture recording apparatus, an optical modulator and a condenser including a laser light oscillator are built in the apparatus, and the optical path between these optical components becomes complicated.
A great deal of time is required for readjustment due to a shift during operation. Moreover, since the optical path passes through an atmosphere such as air, there is also a problem that "fluctuation" occurs due to a "flame flame" due to an air current in the optical path and a temperature difference between the atmosphere, and the amount of light becomes unstable due to floating dust. is there.

[0009]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and aims to improve productivity by distributing a laser beam to a plurality of optical paths and to facilitate adjustment and maintenance of an optical axis. .

For this purpose, the present invention provides a laser light path distribution device for distributing incident laser light to a plurality of optical paths, wherein the light modulation element modulates the incident laser light by changing the angle of the wavefront of the emitted laser light; A beam splitter that distributes the light to the two optical paths according to the angle of the wavefront of the emitted laser light modulated by the light modulation element, and the angle of the wavefront of the emitted laser light that is 100% distributed to one optical path of the beam splitter and the other. Control means for controlling a modulation signal of the light modulating element so as to be alternately switched with an angle of a wavefront of emitted laser light distributed 100% to an optical path, and time-divisionally switches and distributes the incident laser light. Characterized in that it is configured to take it out.

[0011] Further, a laser beam intensity stabilizing means for stabilizing the incident laser beam to a predetermined set value is provided upstream of the light modulation element. An optical modulator for modulating light is provided, and each optical path is connected by an optical fiber.

A laser beam path distribution device for distributing incident laser light to a plurality of optical paths, comprising: a light modulating element for modulating the incident laser light by changing the wavefront angle of the outgoing laser light; A plurality of optical path splitters each including a beam splitter that splits the modulated output laser light into two optical paths according to the angle of the wavefront; and a control unit that controls a modulation signal of an optical modulation element of the plurality of optical path splitters. The plurality of optical path distributors are sequentially cascaded to the two optical paths of the beam splitter, and the divided laser light is extracted from the optical path of each of the beam splitters at the last stage by dividing the laser light by time division. It is characterized by having comprised.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing an embodiment of a laser light path distribution device according to the present invention, and FIG. 2 is a diagram for explaining the operation of the laser light path distribution device according to the present invention. Ballast, 13 a control device, 14 a light modulation element, 15 a beam splitter, 17 and 24 translucent mirrors, 18 and 25 light quantity detectors,
19 and 26 are light collectors, 20 and 27 are disk substrates, 2
Reference numerals 1 and 28 denote substrate rotating mechanisms, 22 and 29 denote substrate moving mechanisms,
Reference numeral 23 denotes a total reflection mirror.

[0014] In FIG. 1, the light source 11 is a laser beam oscillator for generating a laser beam, the laser beam intensity ballast 12 is stabilized to a predetermined set value L _B which is determined the intensity of the incident laser beam in advance Things. Light modulation element 14
Is, for example, an electro-optical element (EO element) that changes the angle θ of the wavefront (polarization plane) of the output laser light with respect to the incident laser light in accordance with the applied voltage S. The beam splitter 15 This is an optical path distribution beam splitter that distributes incident laser light into two optical paths according to the angle θ of the wavefront. The total reflection mirror 23 is for changing the optical path, and the translucent mirrors 17 and 24 are for detecting outgoing light which partially divide the outgoing light from the two optical paths distributed by the beam splitter 15. Beam splitter. The light quantity detectors 18 and 25 detect the light quantity emitted from the optical path by the laser light split from the translucent mirrors 17 and 24. Disk substrate 20, 2
Reference numeral 7 denotes a workpiece to be subjected to texture processing by laser light to form minute protrusions (bumps) on the surface, and is a magnetic disk substrate or a master substrate of a stamper thereof. The light collectors 19 and 26 transmit the laser beam to the disk substrate 2.
By using an optical system that focuses light at the processing positions 0 and 27 and that has an autofocus function, the stability of light collection can be improved even if the processing surface fluctuates due to the rotation of the disk substrate. Can be.

The disk substrates 20 and 27 are workpieces to be subjected to texture processing having minute irregularities on the surface by a laser beam. The substrate rotating mechanisms 21 and 28 hold the disk substrates 20 and 27 to rotate at a constant rotational speed or a laser beam irradiation point at a constant linear velocity, a substrate moving mechanism 22, 29 is a mechanism for moving the disk substrates 20, 27 in the radial direction. The control device 13 detects the output light amount of each optical path detected by the light amount detectors 18 and 25, the rotation speed of each of the disk substrates 20 and 27 detected by the substrate rotation mechanisms 21 and 28, and the detection amounts by the substrate movement mechanisms 22 and 29. that enter the movement position of the disc substrate 20, 27, set value L _B of the laser light intensity ballast 12, the applied voltage S of the light modulation element 14, the rotational speed and the substrate transfer mechanism 22 of the substrate rotating mechanism 21, 28,
29 to control the position of movement.

In the above configuration, the laser light emitted from the light source 11 is transmitted to the laser light intensity stabilizer 12 by the set value L.
_B , and the stabilized laser light is modulated by the light modulator 14 in accordance with the applied voltage S, and the wavefront angle θ
Is changed, and the emitted laser light a ′ is distributed to the optical paths b and c by the beam splitter 15 in accordance with the change in the angle θ of the wavefront. That is, in the beam splitter 15, FIG.
By distributing the emitted laser light when the applied voltage S is at the high level to the optical path b and switching the emitted laser light when the applied voltage S is at the low level to the optical path c as shown in FIG.
Switch and distribute in time division. That is, the light modulation element 1
4 and the beam splitter 15 constitute an optical path distributor. The laser light switched and distributed in this manner is passed from the optical path b through the condenser 19 to the disk substrate 20.
Then, processing is performed by alternately irradiating the disk substrate 27 from the optical path c through the condenser 26. The irradiation positions of the disk substrates 20, 27, that is, the processing positions, are controlled by the rotation positions of the substrate rotation mechanisms 21, 28 and the movement positions of the substrate movement mechanisms 22, 29. Disk substrates 20, 27
Is determined based on the intensity of the irradiated laser beam, and the irradiation width (time) is determined based on the processing size.

FIG. 3 is a diagram for explaining a change in the angle of the wavefront of the laser light emitted from the optical modulator constituting the optical path distributor and the optical path distribution. Reference numeral 31 denotes an optical modulator, and 32 denotes a beam splitter.

In FIG. 3, a light modulator 31 for distributing a laser beam path and a beam splitter 32 have, for example, the following relationship. That is, when the applied voltage S is 0, the light modulating element 31 emits a laser beam a ′ having a wavefront angle θ of 0 ° with respect to the incident laser beam a as shown in FIG. At the predetermined value Vf, the wavefront angle θ is 90 ° with respect to the incident laser light a as shown in FIG.
In addition, the beam splitter 32 distributes the component of the incident laser light a ′ having the wavefront angle θ of 0 ° to the optical path b as shown in FIG. It is assumed that a component whose wavefront angle θ is 90 ° is distributed to the optical path c. From these relationships,
As shown in FIG. 2, when the voltage S applied to the light modulation element 31 is supplied as a pulse signal of Vf, the light can be switched and distributed between the optical paths b and c. Is set between 0 and Vf, FIG.
As shown in (D), the incident laser beam a 'can be distributed to the optical paths b and c at a constant ratio.

Therefore, by using a combination of the light modulation element 31 and the beam splitter 32 as a basic configuration,
An optical path distributor is configured by controlling the applied voltage S of the light modulating element 31 so as to switch and distribute the incident laser light in a time-division manner, or by controlling the applied voltage S of the light modulating element 31 so as to distribute a constant ratio. can do. Similarly, by controlling the voltage applied to S of the optical modulator 31 so as to eliminate by the emission intensity of the light path c detected by the light amount detector is compared with a set value L _B error, the intensity of the output laser beam of a predetermined set value it is possible to stabilize the L _B, can be a laser beam intensity ballasts, by controlling the voltage applied to S of the light modulation element 31 in the arbitrary waveform may be optical modulator. The light modulation element 31 and the beam splitter 3 shown in FIG.
By using a plurality of optical path splitters composed of two and sequentially cascading the two optical paths of the beam splitter, a multi-distribution apparatus of laser light can be realized. FIG. 4 shows an example of the configuration.

FIG. 4 is a diagram showing another embodiment of a laser beam path distribution device which enables multi-distribution of laser light, and FIG. 5 illustrates an example of a multi-distribution operation by a combination of ratio distribution and switching distribution. FIG. 6 is a diagram for explaining an example of a multi-distribution operation by switching distribution.
8, 52 are light modulation elements, 42 is a control device, 43, 49,
53 is a beam splitter, 44 and 46 are translucent mirrors, 4
Reference numerals 5 and 47 denote light amount detectors, and reference numerals 50, 51 and 54 denote total reflection mirrors.

In FIG. 4, in order to realize multi-distribution of laser light, light modulation elements 48 and beam splitters 49 and light modulation elements 52 are further provided on respective optical paths b and c distributed by a light modulation element 41 and a beam splitter 43. And the beam splitter 53 are connected in cascade. Here, when the applied voltage S1 of the light modulation element 41 is controlled so that the wavefront angle θ is 45 ° as shown in FIG.
1 and the beam splitter 43 equally distribute the incident laser light equally to the optical paths b and c. Therefore, by controlling the light modulating element 48 and the beam splitter 49 and the light modulating element 52 and the beam splitter 53 in the same manner as the light modulating element 14 and the beam splitter 15 shown in FIG. 1, respectively, S2 and S3 in FIG. By controlling the applied voltage shown in (1), the light is switched and distributed to four optical paths as shown in (d) to (g).

When it is desired to emit the light to each optical path with the intensity of the incident laser light, the light is modulated and distributed to the optical paths b and c by the light modulating element 41 and the beam splitter 43 as shown in FIG. Then, the light modulation element 48 and the beam splitter 4
9, the light modulation element 52 and the beam splitter 53
In the same manner as described above, by controlling the applied voltage, the light is switched and distributed to four optical paths as shown by d to g. Note that the output light of the optical paths f and g is output from the optical paths d and e when the laser light output of the optical path c is on.
The output is the same as In this case, if the switching frequency of the optical paths d to g is doubled with respect to the switching frequency of the optical paths b and c, that is, if the switching frequency of the next stage is doubled with respect to the upper stage, the signal of the frequency dividing circuit is obtained. The applied voltage control circuit can be configured with a simple circuit using the circuit.

FIG. 7 is a view showing still another embodiment of a laser light path distribution device which enables multi-distribution of laser light. Reference numerals 61 to 63 denote light modulation elements, and reference numerals 64 to 66 denote beam splitters.

Further, an example of a configuration in which a laser beam multi-distribution device is realized by using a plurality of configurations including a light modulation element and a beam splitter as an optical path distributor and sequentially cascading the two optical paths of the beam splitter. FIG. 7 shows a plurality of modes as follows.

First, as a first control mode, the light modulation elements 61 to 63 and the beam splitters 64 to 66 are arranged so that the laser light is distributed to the light path to the optical path.
1 to 63 are controlled and distributed in the same configuration as the light modulation element 14 and the beam splitter 15 shown in FIG.

As a second control mode, the light modulation element 61
63 and the beam splitters 64 to 66 switch and distribute the laser light to the optical path.
63 is controlled. Further, the light modulation element 14 and the beam splitter 15 shown in FIG.

As a third control mode, the light modulation element 61
And the beam splitter 64, and control the applied voltage to the light modulation elements 61 to 63 so that the light modulation elements 62 and 63 and the beam splitters 65 and 66 are switched and distributed. In this case, it is necessary to switch and distribute the optical path in the same configuration as the light modulation element 14 and the beam splitter 15 shown in FIG.

When the optical path distribution device according to the present invention is used in a processing device, for example, a texture recording device, a high-power laser light oscillator is used, so that cooling is usually performed by water cooling or forced air cooling. When such an oscillator is built into the device, the vibration of cooling is transmitted to the device, and the optical axis shifts due to the vibration. In the case of water cooling, the device is damaged by water leakage due to loosening of the contact part or rising water pressure. Occurs. In addition, the laser beam is radiated from the light source through the laser beam intensity stabilizer, optical path distributor, beam splitter, translucent mirror, total reflection mirror, concentrator, etc. Optical axis alignment becomes important.
Moreover, even if the optical axis is adjusted with great effort,
If the optical axis shifts due to aging or replacement of optical components during operation, or the optical axis shifts due to impact, the adjustment requires much more time, and a great burden is required for optical axis adjustment and maintenance. Therefore, in the texture recording apparatus according to the present invention, the optical component is connected to the optical component by an optical waveguide, that is, an optical fiber. This makes it easy to adjust the optical axis and provides an optical device that is not affected by the atmosphere of the optical path.

It should be noted that the present invention is not limited to the above embodiment, and various modifications are possible. For example, in the above embodiment, an electro-optical element (E
Although the example using the O element was described, the acousto-optic element (AO
Element) Other elements having similar functions may be used.
In addition, the incident laser light is time-divided into a plurality of optical paths, switched, distributed, and taken out, and used for processing, etc.
Furthermore, an optical modulator may be inserted and connected to the optical path to modulate the waveform of the emitted laser light into a desired shape according to the processing conditions, and not only in a processing apparatus but also in an apparatus using incident laser light. The present invention may be similarly applied to an apparatus that distributes and uses the laser light.

[0030]

As is apparent from the above description, according to the present invention, a light modulating element for modulating the incident laser light by changing the angle of the wavefront of the outgoing laser light, and the light modulated by the light modulating element. 2 depending on the angle of the wavefront of the emitted laser light
Combined with a beam splitter that distributes light to two optical paths and controls the voltage applied to the light modulation element to distribute the incident laser light to two optical paths, it can be used in a processing device to move multiple processing parts without using a moving mechanism. Laser light, thereby improving productivity and improving processing accuracy.

[Brief description of the drawings]

FIG. 1 is a diagram showing an embodiment of a laser light path distribution device according to the present invention.

FIG. 2 is a diagram for explaining the operation of the laser light path distribution device according to the present invention.

FIG. 3 is a diagram for explaining a change in an angle of a wavefront of a laser beam emitted from an optical modulation element included in an optical path distributor and an optical path distribution;

FIG. 4 is a view showing another embodiment of a laser light path distribution device which enables multi-distribution of laser light.

FIG. 5 is a diagram for explaining an example of a multi-distribution operation based on a combination of ratio distribution and switching distribution.

FIG. 6 is a diagram for explaining an example of a multi-distribution operation by switching distribution.

FIG. 7 is a diagram showing still another embodiment of a laser light path distribution device that enables multi-distribution of laser light.

FIG. 8 is a view for explaining a conventional example of a laser beam processing apparatus.

[Explanation of symbols]

11: light source, 12: laser light intensity stabilizer, 13: control device, 14: light modulation element, 15: beam splitter,
17, 24: translucent mirror, 18, 25: light intensity detector, 1
9, 26: Concentrator, 20, 27: Disk substrate, 21,
28: substrate rotating mechanism, 22, 29: substrate moving mechanism, 23
… Total reflection mirror

Claims (13)

[Claims] 1. A laser light path distribution device for distributing incident laser light to a plurality of optical paths, wherein the light modulation element modulates the incident laser light by changing the wavefront angle of the emitted laser light, and the light modulation element. A beam splitter that splits the light into two optical paths in accordance with the angle of the wavefront of the output laser light modulated by the beam splitter; 100% splits the angle of the wavefront of the output laser light that is split 100% into one optical path of the beam splitter and 100% into the other optical path. Control means for controlling the modulation signal of the light modulation element so as to alternately switch between the angle of the wavefront of the emitted laser light to be distributed, and time-divisionally switch and distribute the incident laser light so as to extract it. A laser light path distribution device characterized by comprising. 2. The laser light path distribution device according to claim 1, further comprising a laser light intensity stabilizing means for stabilizing the incident laser light to a predetermined value before the light modulation element. 3. The laser beam path distribution device according to claim 1, further comprising an optical modulator that modulates the emitted laser light in an optical path of the beam splitter that switches and distributes the incident laser light. 4. The laser light path distribution device according to claim 1, wherein each light path is connected by an optical fiber. 5. A laser light path distribution device for distributing incident laser light to a plurality of optical paths, wherein the first light modulation element modulates the incident laser light by changing the angle of the wavefront of the emitted laser light; A first beam splitter that splits the light into two optical paths according to the angle of the wavefront of the output laser light modulated by the light modulation element; and an output laser that is connected to each optical path of the second beam splitter and emits incident laser light. Second and third light modulating elements for modulating the angle of the wavefront of light and distributing the light to two optical paths according to the angle of the wavefront of the emitted laser light modulated by the second and third light modulating elements. Second and third beam splitters, and control means for controlling modulation signals of the first, second, and third light modulation elements. -A laser light path distribution device characterized in that a laser light switched and distributed by time division of light is extracted. 6. The control means controls a modulation signal of the first light modulation element so as to equally distribute a laser beam to two light paths of the first beam splitter. The modulation signal of the second and third light modulation elements is controlled so as to time-divide and switch and distribute incident laser light to each of two optical paths of a third beam splitter. Laser light path distribution device. 7. The control means of the first to third light modulating elements so as to time-divide and switch and distribute incident laser light to two optical paths of each of the first to third beam splitters. The laser light path distribution device according to claim 5, wherein the modulation signal is controlled. 8. The laser light path distribution device according to claim 5, further comprising a laser light intensity stabilizing means for stabilizing incident laser light to a predetermined set value in a stage preceding said first light modulation element. . 9. The laser light path distribution device according to claim 5, wherein each light path is connected by an optical fiber. 10. A laser beam path distribution device for distributing incident laser light to a plurality of optical paths, comprising: a light modulation element that modulates the incident laser light by changing the wavefront angle of the emitted laser light; and the light modulation element. A plurality of optical path splitters each including a beam splitter that splits the modulated output laser light into two optical paths according to the angle of the wavefront; and a control unit that controls a modulation signal of an optical modulation element of the plurality of optical path splitters. The plurality of optical path distributors are sequentially cascaded to the two optical paths of the beam splitter, and the divided laser light is extracted from the optical path of each of the beam splitters at the last stage by dividing the laser light by time division. A laser light path distribution device characterized by comprising. 11. A laser light intensity stabilizing means for stabilizing incident laser light to a predetermined set value in a stage preceding an optical modulation element of a first stage optical path distributor among the plurality of optical path distributors. The laser light path distribution device according to claim 10, wherein 12. The beam splitter according to claim 10, further comprising an optical modulator for modulating an emitted laser beam in an optical path of said beam splitter for switching and distributing an incident laser.
The laser light path distribution device as described in the above. 13. The laser light path distribution device according to claim 10, wherein each light path is connected by an optical fiber.