JPH02200389A - Laser irradiating device - Google Patents

Abstract

PURPOSE:To easily irradiate the same point of an object to be irradiated with two beams of light by separating laser light to a basic wave and second harmonic wave, focusing both by utilizing a chromatic aberration, matching the basic wave with a focal position, deviating the focus of the second harmonic wave and irradiating the object to be irradiated with this wave. CONSTITUTION:The laser light released from a laser oscillating section 1 is separated to the basic wave and the second harmonic wave which are made the same in optical axis by an output transmission mirror (1st optical means 4). The basic wave and the second harmonic wave separated by the 1st optical means 4 are focused by a focusing lens (2nd optical means) 8 utilizing the chromatic aberration, by which the basic wave is matched with the focal position and the focus of the second harmonic wave is deviated. The object 12 to be irradiated is irradiated with this light. The operations for positioning two beams of the light is facilitated in this way.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a laser irradiation device that separates laser light into a fundamental wave and a second harmonic and irradiates the irradiated object with the separated laser light.

(Prior art) When performing laser processing by irradiating a laser beam onto an irradiated object, two processes such as melt processing and alteration processing (for example, ultraviolet treatment) are performed on the same part of the irradiated object simultaneously or sequentially. I have something to do.

Conventionally, in order to perform these two processes simultaneously or sequentially, light with a wavelength suitable for each process is emitted from separate light sources, and an optical component such as a reflector is used to illuminate the same part of the wave-processed object. I was trying to guide him.

However, if two light sources are used to obtain two lights of different wavelengths, two optical paths are required to guide the light emitted from each light source to the irradiated object.
This may lead to a more complex configuration. In addition, the optical components must be positioned so that the two lights of different wavelengths emitted from separate light sources illuminate the same part of the object to be irradiated, but this positioning can be difficult and time-consuming. . Furthermore, when performing two processes, melting processing and alteration processing, on an irradiated object, one light is irradiated with the focused position of the irradiated object aligned, and the other light is irradiated with the focused position shifted. This has led to complications in the configuration and time-consuming positioning of optical components (problems to be solved by the invention). When irradiating two different lights, two light sources are used, which makes the configuration complicated and makes it difficult to position each light emitted from each light source.

This invention was made based on the end of the article, and its purpose is to be able to obtain two lights of different wavelengths without using two light sources, and to use complex optical components. Match the focal position of one of these two lights without
It is an object of the present invention to provide a laser irradiation device that can irradiate an object with the other side out of focus.

[Structure of the Invention] (Means and Effects for Solving the Problems) In order to solve the above problems, the present invention provides a basic structure in which a laser oscillation section and a laser beam emitted from this laser oscillation section have the same optical axis. a first optical means for separating the wave and a second harmonic;
The fundamental wave and the second harmonic separated by the optical means are focused using chromatic aberration, and the focal position of the first-order fundamental wave is made to match, and the second harmonic is defocused and directed onto the object to be irradiated. and second optical means for irradiating. As a result, it is possible to obtain two lights of different wavelengths from one laser oscillation part, and in addition, it is possible to irradiate the target object with the light of the - one wavelength while aligning the focal position to the irradiated object, and to irradiate the object with the other wavelength. Defocus the light 1. The second optical means can easily perform irradiation using the second optical means.

(Example) An embodiment of the present invention will be described below with reference to the drawings.

The laser irradiation device shown in FIG. 1 includes a laser oscillation section 1. The laser irradiation device shown in FIG. This laser oscillation unit 1 includes, for example, an excitation radar 2 of an alexandrite laser head, a total reflection mirror 3 disposed facing one end face of the excitation radar 2, and a total reflection mirror 3 disposed facing the other end face. and an output transmission mirror 4. The laser oscillation unit 1 of the alexandrite laser oscillates a fundamental wave with a wavelength of 700 to 800 ns, but by selecting the total reflection mirror 3 and the output transmission mirror 4, a fundamental wave with a wavelength of 75 ns is oscillated. be able to.

Between the other end face of the excitation radar 2 and the output transmission mirror 4 is a wavelength conversion element 5 made of β-BaB204 crystal and converting a part of the fundamental wave into a second harmonic with a wavelength of 375 na. It is installed at an angle that satisfies phase matching.

The output transmission mirror 4 is coated with 5i202 and TiO2 alternately, so that the fundamental wave can be sufficiently amplified for laser oscillation, and the second harmonic is not reflected. There is. As a result, a fundamental wave of 750 nm and a fundamental wave of 375 nm are emitted from the laser oscillation section 1.
and the second harmonic of the optical axis are output on the same optical axis.

The fundamental wave and the second harmonic oscillated by the laser oscillation section 1 are focused by the entrance lens 5a, enter the optical fiber 6, and are introduced into the collimating lens system 7 through the optical fiber 6. The fundamental light and second harmonic corrected to parallel light by this collimating lens system 7 are collected by a focusing lens 8 and a quartz plate 9.
And the object 12 to be irradiated is irradiated through the wavelength selection plate 11. The wavelength selection plate 11 can transmit only either the fundamental wave or the second harmonic. Further, the wavelength selection plate 11 and the quartz plate 9 can be moved forward and backward with respect to the optical path by a drive mechanism (not shown).

The focusing lens 8 is made of quartz and, as shown in FIG. 2, has a wavelength of 1.
C has a refractive index of 46, and C has a refractive index of 1.47 for the second harmonic with a wavelength of 375 ns+. 1- For example, 5LSQ-30-35P (Sigma Light I
If you use A Co., Ltd.'s product name), the focal length of the fundamental wave will be 35.1! mm, the focal length of the second harmonic is 33.8 mm
It can be done. In other words, by utilizing the chromatic aberration of the F focusing lens 8, the focal lengths of the fundamental wave and the second harmonic can be changed. Therefore, if the object 12 to be irradiated is positioned so that the focal position of the fundamental wave focused by the focusing lens 8 coincides with F, then the second harmonic will be radiated at a distance of 2 mm at 1° relative to the object 11 to be irradiated. It is possible to irradiate with an out-of-focus amount.

Furthermore, by inserting the quartz plate 9 into the optical path, the amount of defocusing of the 21st harmonic can be further increased. That is, if the passage length of the quartz plate 9 is d, then the fundamental wave and the second
Since an optical path length difference is generated by the product of the refractive index difference with the 15th harmonic and the passage length d, it is possible to increase the amount of defocusing.

The passage length d of the quartz plate 9 can be adjusted by the plate thickness and installation angle.

According to the laser irradiation device having such a configuration, a part of the fundamental wave oscillated from the excitation head 2 of the laser oscillation unit 1 is converted into a second wave by the wavelength conversion element 5, and then transmitted to the output transmission mirror. Output from 4. Further, the fundamental wave which has not been converted into the second harmonic by the V wavelength conversion element 5 is output from the -1-distribution output mirror 4 to -2 with the same optical axis as the second harmonic wave. That is, one laser oscillation unit 1 can output two laser beams with different wavelengths.

The fundamental wave and the second harmonic outputted from the laser oscillation unit 1 pass through an optical fiber 6, are corrected into parallel light by a collimating lens system 7, and are then focused by a focusing lens 8. If the quartz plate and the wavelength selection plate 11 are retracted from the optical path, the fundamental wave focused by the focusing lens 8 will have its focal position matched, and the second harmonic will be defocused. The object 12 to be irradiated will be irradiated. Therefore, the fundamental wave whose focus position is matched is the range u shown by A in FIG.
The object 12 to be irradiated is melt-processed by irradiation with N, and the defocused second harmonic covers a wider range A than the range A irradiated by the fundamental wave of the object 12 shown as B in FIG. It will be irradiated and altered in quality.

The fundamental wave and the second harmonic irradiate the object 12 with their focal positions matched and out of focus due to the chromatic aberration of one focusing lens 8. Therefore, the configuration is not only simpler than when the fundamental wave and the second harmonic are focused using separate optical components, but also because they are incident on the focusing lens 8 with the same optical axis, no particular positioning is required. In both cases, the object 12 can be irradiated with the fundamental wave, the second wave, and the i-wave along the optical axis.

Furthermore, by introducing the quartz plate 9 into the optical path, the amount of defocusing of the second harmonic can be further increased.

On the other hand, if a wavelength selection plate 11 that allows only the fundamental wave to pass, for example, is used, alteration processing by the second harmonic can be controlled by entering the wavelength selection plate 11 into the optical path. If only harmonics are allowed to pass through, melt processing using fundamental waves can be controlled.

Although the above embodiment describes an alexandrite laser, the present invention can also be applied to the case where the fundamental wave of an Nd:YAG laser with a wavelength of 1.0B4 # is converted to a second harmonic with a wavelength of 0.532-. It is not limited to Class I lasers.

[Effects of the Invention] As described above, the present invention separates a laser beam into a fundamental wave and a second harmonic having the same optical axis by a first optical means, and separates a laser beam into a second harmonic wave using chromatic aberration. By means of this means, the focal position of the fundamental wave is made to coincide with the focal position, and the second harmonic wave is defocused so that the object to be irradiated can be irradiated. Therefore, compared to the conventional method of outputting two lights with different wavelengths from separate light sources, this not only simplifies the configuration and makes positioning work easier, but also irradiates the same part of the object with the two lights. It also has the advantage that it can be easily carried out.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention; Fig. 1 is a schematic diagram of the entire apparatus, Fig. 2 is an enlarged plan view of a portion of the object to be irradiated, and Fig. 3 shows the wavelength and refractive index of light due to quartz. This is a graph of the relationship between 1... Laser oscillation unit, 4... Output transmission mirror (first
optical means), 5... wavelength conversion element (first optical means), 8... focusing lens (second optical means), 12...
・Irradiated object. Applicant's agent Patent attorney Takehiko Suzue

Claims (1)

[Claims] a laser oscillation section; a first optical means for separating a laser beam emitted from the laser oscillation section into a fundamental wave and a second harmonic having the same optical axis; The fundamental wave and the second harmonic are focused using chromatic aberration, and the fundamental wave is made to match the focal position and the second harmonic is focused.
A laser irradiation device comprising a second optical means for defocusing harmonics and irradiating an object to be irradiated.