JPS5852616A - Beam expander device - Google Patents

Abstract

PURPOSE:To obtain sharp expanded light by unitizing beam expander device structure, and eliminating electrolytic dissociation which occurs specially when the energy of high-power laser converges to one point. CONSTITUTION:A beam B from a laser, etc., is focused at a focal point through a small-diameter convex lens 8, filtered through a space-frequency filter 9, and transmitted through a large-diameter lens 7 to be emitted as expanded light. In this case, a vacuum is produced at least near the filter 9 to eliminate the possibility of electrolytic dissociation even if a high-power laser beam is converged to generate high energy.

Description

[Detailed Description of the Invention] This relates to an expander device, in which the structure of the beam expander device is unitized, and the ionization phenomenon that occurs when the energy of a high-power laser is concentrated in one point is eliminated to achieve clear expansion. The purpose is to obtain light.

Conventionally, there is a means to expand the beam such as a scissor.

Two typical devices are the so-called Galileo type and Kepreel type.

In the Carileo type, a concave lens and a convex lens are arranged and fixed at a predetermined interval, and the beam incident on the concave lens is expanded and then further expanded through the convex lens, but the beam cannot be focused. Therefore, no spatial frequency filtering is performed.

There was a regret that it was not possible to extract only pure parallel light to the concave lens.

On the other hand, in the Kepreel type, a pair of convex lenses is fixed at a predetermined interval, and the beam incident on one convex lens is focused once, filtered by a spatial frequency filter at this focal position, and then the beam is filtered by the other convex lens. This method further expands the beam, but if the beam is a high-power laser, the energy when concentrated at one point is extremely large, causing ionization, which causes not only the impact sound but also the transmitted expansion. The drawback was that it resulted in significant disturbances in the light.

Therefore, in the past, in the case of high-power lasers, the Galileo type expander device had to be adopted, and a major problem remained in filtering.

The single expander device requires a predetermined lens to be fixed at a fixed position, and its setting is extremely difficult to implement.

The present invention utilizes the above-mentioned advantages of Kepreel filtering while eliminating its disadvantages.

Furthermore, the Beam Expansion device was developed to integrate the device into an integrated unit, and the holder is completely sealed by placing a pair of optical elements such as lenses at both open ends of the cylindrical holder. In addition, at least the focal point inside the holder is evacuated.An embodiment of the present invention will be described below with reference to the drawings.

First, reference numeral I in the figure is a cylindrical holder having a predetermined length, and an intake cylinder 3 communicating with the inside of the holder 1 is attached to a part of the cylindrical wall 2 via a cock 4 so as to be openable and closable. Rare,
The tip of this intake cylinder 3 communicates with a vacuum device (not shown).

Both ends of the holding body 1 are open, and one end thereof is provided with an inner collar 5, 1 having a large inner diameter, and the other end is provided with an inner collar 6 having a small inner diameter. In the aperture, predetermined convex lenses 7 and 8 as optical bodies are fitted airtightly through an adhesive or the like, facing the same optical axis, and further within the holder, A spatial frequency filter 9 having a pinhole, linear or wedge-shaped slit, etc. is fixed at the focal point of the small diameter convex lens 8.

Therefore, by closing the cock 4, the holding body J is sealed. However, in the expander assembly according to the present invention, a desired amount of air is removed from the holding body 1 by the vacuum device described above, and the air is sealed. .

This is so that the degree of vacuum can be adjusted freely depending on the purpose and situation of use, but in some cases, the cock 4 may be installed to pump a predetermined amount of air into the intake cylinder in 3 sounds and 13 minutes. It is also possible to apply a welding seal using glass or the like after removing it.

Unfortunately, in the above embodiment, the case where the entire inside of the holder 1 is completely vacuum has been described, but as will be described later, in the present invention, only the vicinity of the pinhole etc. of the spatial frequency filter 9 needs to be vacuum. .

[Short cylindrical holder with fixed spatial frequency filter 9]
Both ends are sealed with flat glass to remove air,
It is also possible to arrange convex lenses at the front and rear positions of the holder 1, respectively.

In the drawings showing the configuration as described above, a laser beam B passes through a small diameter convex lens 8, is condensed at the focal point, is filtered by a spatial frequency filter 9, and then passes through a large diameter lens 7. It passes through and is emitted as enlarged light.

In the present invention, at least the internal filter 9
Since there is a vacuum in the vicinity, even if a high-power laser beam is focused and high energy is generated, there will be no ionization phenomenon.

However, the degree of vacuum inside will be determined according to the power state of the beam.

In addition, 9 uses the expander device body of the present invention.

Instead of creating a vacuum state, a method of injecting a gas such as argon into the interior could be considered, but there is no doubt as to how effectively it would work against the instantaneous electromagnetic phenomenon.

The beam expanding device according to the present invention has the structure and functions as described above. Therefore, even if a high-power laser beam is expanded using the new Kepreel type method, since it is a vacuum, no electromagnetic force will be generated, so the obtained expanded light will not be disturbed at all.9 Moreover, spatial frequency filtering As a result, the expanded light becomes extremely clear.

In addition, it is possible to securely hold the pair of convex lenses and the filter together via the holder.

It does not require complicated setting work, and can be expected to greatly save labor during implementation.

The invention has a simple structure and is easy to manufacture, and it is possible to obtain the desired clear magnified light.

It is an epoch-making product that has many excellent functions and effects, such as being able to improve workability by unitizing it.

[Brief explanation of the drawing]

The drawing is a sectional view of a beam expander device body according to the present invention. Symbol h division]... Holder, 3. Intake cylinder, 7, 8... Convex lens. 9. Spatial frequency filter 1, Applicant (inventor) Koki Kiyohara Agent (patent attorney) Toshiyuki Arai 12

Claims (1)

[Claims] A pair of light condensers such as lenses are disposed facing each other at both opening ends of a cylindrical holder, a spatial frequency filter is fixed at a predetermined position within the holder, and a pinhole of at least the spatial frequency filter is fixed inside the holder. A beam expander device characterized in that the vicinity of a slit having a desired shape is kept in a vacuum state.