JPH02163723A - Optical system for making laser light intensity distribution uniform - Google Patents

Abstract

PURPOSE:To obtain a laser working spot which has a uniform laser light intensity distribution by combining half mirrors having specific reflectivity, total reflecting mirrors and a condensing lens. CONSTITUTION:Laser light L is reflected by the half mirror 1 at 90 deg. reflection angle with the specific reflectivity of the mirror and is made incident to the total reflecting mirror 2. The laser light passes the mirror 2 and the total reflecting mirror 3 at 90 deg. reflection angle, is reflected by the half mirror 4 at 90 deg. reflection angle with the specific reflectivity so as to be made incident in parallel with the laser light L to the mirror 1. On the other hand, the light transmitted through the mirror 4 is reflected by the total reflecting mirror 5 at 90 deg. reflecting angle and is made incident in parallel with the laser light L to the mirror 1. The light rays reflected from the mirrors 4, 5 are fed back again to the mirrors 4, 5 through the mirrors 1, 2, 3. The number of feedback times and the diameter of the incident light beam to the condenser lens 6 are regulated by the sizes of the mirrors 1 to 5 and the perpendicular distance between the mirrors 4 and 5. The laser beam working spot having the uniform intensity distribution is obtd. in this way.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to an optical system with uniform laser beam intensity distribution for forming a laser processing spot with uniform laser beam intensity distribution, and particularly relates to an optical system of a multimode laser. It is something.

[Conventional technology]

Conventionally, this type of multimode laser light intensity distribution uniform optical system expands the multimode laser light emitted from a laser oscillating device using a beam expander, and extracts the uniform part of the laser light intensity distribution using an aperture. The method is being taken my friend.

[Problem to be solved by the invention]

The conventional multimode laser light intensity distribution uniform optical system described above is a method in which the multimode laser light emitted from a laser oscillator is expanded using a beam expander, and the uniform part of the laser light intensity distribution is extracted using an aperture. Therefore, there is a problem in that the effective laser energy value that can be extracted is reduced compared to the oscillation laser energy value.

[Means to solve the problem]

The present invention was made in order to improve the above-mentioned conventional problems, and includes a first half mirror that reflects a laser beam oscillated from a laser oscillator at a reflection angle of 90 degrees with a specific reflectance; The reflected laser beam from the half mirror of 1 is 90
a first total reflection mirror that totally reflects the reflected laser beam from the first total reflection mirror at a 90 degree reflection angle; A second half mirror that reflects the laser beam reflected from the mirror at a 90-degree reflection angle with a specific reflectance, and a second 71-7 mirror that totally reflects the transmitted laser beam after passing through the mirror at a 90-degree reflection angle. Third
The total reflection mirror and the condenser lens that condenses the laser beam transmitted from the first half mirror constitute an optical system with uniform laser light intensity distribution.

[Effect]

In the present invention, the laser beam oscillated from the laser oscillator is reflected by a combination optical system consisting of a No. 7 mirror with a reflection angle of 90 degrees and a total reflection mirror. By superimposing the distributions and condensing the laser beams with the superimposed laser beam intensity distributions transmitted from the first half mirror by a condenser lens, it is possible to form a laser processing spot with a uniform laser beam intensity distribution.

〔Example〕

Next, the present invention will be explained with reference to the drawings.

FIG. 1 is a configuration diagram showing an optical system with uniform laser light intensity distribution according to an embodiment of the present invention. In the same figure, laser light emitted from a laser oscillator (not shown) enters a first half mirror 1, and is reflected by this first half mirror 1 at a 90 degree reflection angle with a specific reflectance. The light is incident on the first total reflection mirror 2. This laser beam passes through the first total reflection mirror 2 and the second total reflection mirror 3 at a reflection angle of 90 degrees, and is reflected at a constant reflectance of 90% by the second half mini-4).
The laser beam is reflected at a degree reflection angle and is incident on the first half mirror IK in parallel with the laser beam emitted from the laser oscillator. On the other hand, the laser beam transmitted through the second half mirror 4 is reflected by the third total reflection mirror 5 at a reflection angle of 90 degrees, and enters the first half mirror 1 in parallel with the laser beam emitted from the laser oscillator. be done. 1st second half mirror 4
The laser beam reflected from the third total reflection mirror 5 is reflected from the first half mirror IK at a 90 degree reflection angle with a specific reflectance, and is reflected from the first total reflection mirror 2. It passes through the second total reflection mirror 3 and returns to the second 7-f mirror 4. Third
The light is incident on the total reflection mirror 5.

Here, the number of times the laser beam is fed back and the beam diameter of the laser beam incident on the condensing lens 6 are determined by the size of the half mirrors 1 and 4 and the total reflection mirror 2°3.5. Second half mirror 4 and third total reflection mirror 5
It is defined by the vertical distance between

FIG. 2(a) is a diagram showing the intensity distribution of the laser beam oscillated from the laser oscillator, and the upper laser beam intensity is indicated by the dotted line with respect to the optical axis passing through the center of the condenser lens 6 in FIG. The distribution is getting stronger. Figure 2 ('b) shows the laser beam emitted from the laser oscillator, passes through the laser beam intensity distribution uniform optical system, and shows the laser beam before entering the condenser lens 6 when the number of feedback is one. , a diagram showing the relationship between laser beam intensity distribution and the distance d between the laser beam beams is defined by the vertical distance between the second half mirror 4 and the third total reflection mirror 5.

〔Effect of the invention〕

As explained above, the present invention has the effect of forming a laser processing spot with a uniform laser beam intensity distribution by combining a half mirror with a specific reflectance, a total reflection mirror, and a condensing lens. .

[Brief explanation of the drawing]

FIG. 1 is an optical system configuration diagram of an optical system with uniform laser light intensity distribution according to an embodiment of the present invention, and FIG.
01 a@ψ・First half mirror 21I・・Fist first total reflection mirror 3 -・1111 Second total reflection mirror 4@11
#@Second half mirror-511eIII Third total reflection mirror/condensing lens.

Claims (1)

[Claims] a multi-mode laser oscillator; a first half mirror that reflects the laser beam emitted from the laser oscillator at a reflection angle of 90 degrees; and a first half mirror that totally reflects the reflected laser beam from the first half mirror at a reflection angle of 90 degrees. 1 total reflection mirror and the reflected laser beam from the first total reflection mirror at a reflection angle of 90
a second total reflection mirror that totally reflects the laser beam from the second total reflection mirror at a reflection angle of 90 degrees, and a second half mirror that reflects the reflected laser beam from the second total reflection mirror at a reflection angle of 90 degrees; A third total reflection mirror that totally reflects light at a reflection angle of 90 degrees, a laser beam reflected from the second half mirror, a laser beam reflected from the third total reflection mirror, and a laser beam from the laser oscillator. 1. A uniform laser beam intensity distribution optical system, comprising a condenser lens for condensing transmitted laser beams incident on the first half mirror, and forming a laser processing spot with a uniform laser intensity distribution.