JPH0651236A - Uniforming optical device - Google Patents

Abstract

PURPOSE:To form a uniform laser beam intensity distribution by providing spherical surfaces at both ends of a transparent tube, and causing a laser beam to impinge on one of the spherical surfaces. CONSTITUTION:A quartz tube 1 having a spherical surface at each end has antireflection films attached to both of the spherical end surfaces thereof and has its side faces optically polished. Incoming parallel laser beams 4 of the Gaussian distribution, where intensity is great at the center, impinge on one of the spherical end surfaces 2 of the quartz tube and is converged inside the quartz tube 1 and converted into a laser beam 5. In this case, if the angle of incidence of the laser beam 5 on the side face of the quartz tube 1 is great, the laser beam 5 totally undergoes multiple reflections inside the quartz tube 1 and has its intensity distribution uniformed and is output as parallel laser beams 7 with a uniform intensitiy distribution from the emission end of the quartz tube 1, and the laser beams 7 are used for machining. Therefore, the laser beam of the Gaussiaion distribution can be made to have a uniform laser intensity distribution using a single optical component and by means of low-cost, simple adjustment.

Description

Detailed Description of the Invention

[0001]

[Industrial application] In recent years, as a processing method using a laser beam, a method for uniformly processing a large area at one time has been required in addition to a method for finely punching and cutting in pursuit of light converging property. There is a need for an optical system that creates a laser beam having an intensity distribution.

The present invention relates to a homogenizing optical device for uniformizing the intensity distribution of a laser beam.

[0003]

2. Description of the Related Art Among conventional methods for making the intensity distribution of a laser beam uniform, a method using a convex lens and a transparent tube will be described below.

FIG. 4 shows a conventional convex lens and a transparent tube.
It shows a method of making the intensity distribution of the laser beam uniform. In FIG. 4, reference numeral 1 denotes a quadrangular prism quartz tube, an end face for laser input / output is provided with an antireflection screen, and side faces are optically polished, and 2 and 3 are spherical convex lenses with a double-sided antireflection film. An incident laser beam 4 having a Gaussian distribution with parallel light and a large intensity at the central portion is condensed by a convex lens 2 immediately after entering the quartz tube 1 and becomes a laser beam 5. When the incident angle of the laser beam 5 with respect to the side surface of the quartz tube 1 is larger than the total reflection angle, all the laser beams 5 are multiply reflected inside the quartz tube 1 and the intensity distribution becomes uniform, and the laser beam 6 is emitted from the emitting end.
Will be output. Since the laser beam 6 spreads out from the emission end of the quartz tube 1, it is made parallel by the convex lens 3 and becomes a parallel laser beam 7 having a uniform intensity distribution, which is used for processing.

[0005]

However, in the homogenizing optical device having the conventional structure, the quartz tube and the convex lens 2 are used.
The number of the optical components was 3 and the anti-reflection film was 6; therefore, the number of components was large and it was expensive. Further, there is a problem in that the optical axis adjustment is made up of three parts, the number of adjustment points is large, and the device becomes large.

The present invention addresses the above-mentioned problems by using a transparent tube in which both ends of the transparent tube have a cylindrical surface or a spherical shape, and further, by using an optical system in which a part of the transparent tube is made thinner than both ends. It is an object of the present invention to provide a homogenizing optical device capable of obtaining a uniform laser intensity distribution by reducing the number of optical components to one, reducing the number of antireflection films to two, and reducing the number of adjustment points. .

[0007]

In order to achieve the above object, the homogenizing optical device of the present invention uses a transparent tube in which both ends of the transparent tube are cylindrical or spherical, and further, a part of the transparent tube. It is characterized in that a uniform laser intensity distribution is created by using an optical system in which both ends are made thinner and making a laser beam incident on one end face thereof.

[0008]

According to the present invention, the device configured as described above provides
It is possible to create a laser beam having a Gaussian intensity distribution by a single optical component, and to make a uniform laser intensity distribution by inexpensive and simple adjustment.

[0009]

【Example】

(Embodiment 1) An apparatus for producing a uniform laser intensity distribution by a single optical component in one embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows the construction of an apparatus in which a quartz tube having a quadrangular prism whose both ends are spherical is used as the transparent tube to make the intensity distribution of the laser beam uniform. In FIG. 1, reference numeral 1 is a quadrangular prismatic quartz tube whose both ends are spherical surfaces, end surfaces of both spherical surfaces are provided with an antireflection film and side surfaces are optically polished, and 4, 5 and 7 are laser beams. Incident laser beam 4 with parallel light and Gaussian distribution with high intensity in the center
Is incident on the spherical end surface 2 of the quartz tube and condensed in the quartz tube 1 to become a laser beam 5. When the incident angle of the laser beam 5 with respect to the side surface of the quartz tube 1 is larger than the total reflection angle, all the laser beams 5 are multi-reflected inside the quartz tube 1 and the intensity distribution becomes uniform, and the laser beam 5 is more uniform at the exit end of the quartz tube 1. The parallel laser beam 7 having an intensity distribution is output and used for processing.

(Embodiment 2) An apparatus for producing a uniform laser intensity distribution in one direction by a single optical component according to a second embodiment of the present invention will be described below with reference to the drawings.

FIG. 2 shows the structure of an apparatus in which the intensity distribution of a laser beam is made uniform by using a quartz tube having a square pole shape whose both ends are cylindrical surfaces as a transparent tube. In FIG. 2, 1 is a quadrangular prismatic quartz tube whose both ends are cylindrical surfaces, the end surfaces of both cylindrical surfaces are antireflection films and the side surfaces are optically polished, and 4, 5 and 7 are laser beams. is there. An incident laser beam 4 having a Gaussian distribution, which is parallel light and has a large intensity in the central portion, is incident on the spherical end surface of the quartz tube and is linearly condensed in the quartz tube 1 to become a laser beam 5. When the incident angle of the laser beam 5 with respect to the side surface of the quartz tube 1 is larger than the total reflection angle, all the laser beams 5 are multiple-reflected inside the quartz tube 1 and only the intensity distribution in the converged direction becomes uniform, and the exit end. Then, the laser beam 7 is output. The laser beam 7 is a parallel laser beam having a uniform intensity distribution in only one direction due to the emission end of the quartz tube 1, and is used for processing. Further, by using a quartz tube having a different curvature cylindrical surface to make the intensity distribution of the laser beam 7 in a direction not uniform, a laser beam having a uniform intensity distribution as in Example 1 is obtained. Can also be created.

(Embodiment 3) An apparatus for producing a uniform laser intensity distribution by a single optical component in a third embodiment of the present invention will be described below with reference to the drawings.

FIG. 3 shows the configuration of an embodiment of the present invention. In FIG. 3, reference numeral 1 denotes a quadrangular prismatic quartz tube whose both ends are spherical surfaces. The end faces of both spheres are provided with an antireflection film and the side surfaces are optically polished. After that, it is thickened in a taper shape,
4, 5 and 7 are laser beams. Since the quadrangular prism becomes thin, the number of reflections of the laser beam 5 passing through the quadrangular prism becomes larger than that in the case where the laser beam 5 is not thin. Therefore, the intensity distribution of the laser beam is made more uniform as compared with the case where the quartz tube is not thin, and the size in the longitudinal direction of the quartz tube can be shortened, so that the size can be reduced.

[0015]

The present invention makes it possible to produce a uniform laser intensity distribution of a laser beam having a Gaussian intensity distribution by means of a single optical component by means of the apparatus constructed as described above. , The adjustment can be easy.

[Brief description of drawings]

FIG. 1 is a configuration diagram of an apparatus for creating a uniform laser intensity distribution by making both ends of a transparent tube spherical and making laser light incident on one spherical surface in Example 1 of the present invention.

FIG. 2 is a configuration of an apparatus for forming a uniform laser intensity distribution in only one direction by making both ends of a transparent tube into a cylindrical surface and injecting a laser beam into one of the cylindrical surfaces in Example 2 of the present invention. Figure

FIG. 3 is a diagram illustrating a transparent tube according to a second embodiment of the present invention, wherein both ends of the transparent tube have a cylindrical surface or a spherical surface.
Part of the transparent tube of 2 is made thinner than both ends, and a laser beam is incident on one end surface of the transparent tube to create a uniform laser intensity distribution.

FIG. 4 is a configuration diagram of a conventional example in which a uniform laser intensity distribution is created using a transparent tube and two convex lenses.

[Explanation of symbols]

 1 square prism transparent quartz tube 2, 3 convex lens 4 laser beam (incident light: parallel light) 5 laser beam (multiple reflection in transparent quartz tube) 6 laser beam (emitted light: spread light) 7 laser beam (emitted light: parallel light) light)

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yuji Uesugi 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd.

Claims (3)

[Claims] 1. A homogenizing optical device in which both ends of a transparent tube are spherical and laser light is incident on one of the spherical surfaces. 2. A homogenizing optical device for producing a uniform laser intensity distribution in only one direction by making both ends of a transparent tube into a cylindrical surface and injecting laser light into one of the cylindrical surfaces. 3. A uniform laser is provided by making both ends of the transparent tube into a cylindrical surface or a spherical shape, and making a part of the transparent tube thinner than both ends and injecting one end surface laser beam. A homogenizing optical device that creates an intensity distribution.