JP2001024260A - Cavity for solid laser - Google Patents

Abstract

PROBLEM TO BE SOLVED: To use an aperture without any adjustment by eliminating the need for a movable mechanism in complicated structure. SOLUTION: This cavity 8 contains a laser rod 2 made of a solid laser medium together with an exciting lamp 3 (exciting light source), and those laser rod 2 and exciting lamp 3 can be cooled with cooling water 9. In this case, the aperture 26 which limits the beam diameter of laser light emitted from an axially end part of the laser rod 2 by passing the laser light through a small hole 25 is mechanically positioned and mounted on the laser rod 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a cavity for a solid-state laser.

[0002]

2. Description of the Related Art As shown in FIG. 3, in a general solid-state laser oscillator, a laser rod 2 (for example, a solid-state laser medium such as a Nd: YAG laser rod) and an excitation lamp 3 (krypton lamp) are provided in a housing called a cavity 1. And the cavity 1 is positioned and installed on an optical surface plate whose dimensions and horizontality have been processed with high precision, and a transmission mirror 4 (which forms an optical resonator at front and rear positions of the cavity 1). A partial reflection mirror) and a reflection mirror 5 (total reflection mirror) are arranged, and a laser rod 2 is excited in a cavity 1 by turning on an excitation lamp 3 to emit light.
The light is reciprocated between the transmission mirror 4 and the reflection mirror 5 to repeatedly enter and exit the laser rod 2, thereby causing optical resonance to amplify the energy of the light.
The laser light can be oscillated through the interface.

In this type of laser oscillator, a pinhole-shaped small hole 6 is formed at the center between the cavity 1 and each of the transmission mirror 4 and the reflection mirror 5 located before and after the cavity 1. A thin plate-shaped aperture 7 is arranged, and the laser beam in an extra outer portion having a required beam divergence angle is cut off by passing through the small hole 6 to limit the beam diameter. So that you can keep

[0004]

However, in such a conventional structure, since the apertures 7 are independently disposed outside the cavity 1, the apertures 7 are adjusted in two directions of up, down, left and right with respect to the optical axis. A movable mechanism for supporting the movable mechanism is required, and the movable mechanism must have a water-cooled structure so as to remove heat when the aperture 7 interferes with the extra laser light. However, there has been a problem that it is fragile.

The present invention has been made in view of the above circumstances, and has as its object to eliminate the need for a movable mechanism having a complicated structure and to use an aperture without adjustment.

[0006]

SUMMARY OF THE INVENTION The present invention is directed to a solid-state laser cavity configured to receive a laser rod made of a solid-state laser medium together with an excitation light source and to cool the laser rod and the excitation light source with cooling water. An aperture for restricting a beam diameter by passing a laser beam emitted from an axial end of a laser rod through a small hole is mechanically positioned with respect to the laser rod, and is provided.

Therefore, according to the present invention, it is possible to incorporate the aperture into the cavity and to obtain the mechanical position accuracy with respect to the laser rod in advance, so that an independent movable mechanism for the aperture is not required, and when the cavity is replaced. It is possible to use the aperture without adjustment.

Further, since the laser rod and the excitation light source housed in the cavity are configured to be cooled by the cooling water, heat generated when the aperture interferes with the extra laser light is indirectly generated by the cooling water in the cavity. Will be removed.

Further, in the present invention, it is preferable that the cavity body is assembled on a metal base plate, and that an aperture is attached to a laser light entrance / exit opening opened at the front and rear end surfaces of the cavity body.

In this manner, the low-rigidity cavity body, which is generally made of synthetic resin having both insulation and corrosion resistance, is reinforced with a metal base plate to suppress distortion deformation. Therefore, the aperture can be positioned with high accuracy with respect to the laser rod.

[0011]

Embodiments of the present invention will be described below with reference to the drawings.

FIGS. 1 and 2 show an example of an embodiment of the present invention, in which the same reference numerals as those in FIG. 3 denote the same parts.

In FIG. 1, reference numeral 8 denotes a solid-state laser cavity configured to receive a laser rod 2 made of a solid-state laser medium together with an excitation lamp 3 and cool the laser rod 2 and the excitation lamp 3 by cooling water 9. The cavity 8 shown in FIG.
A cooling water tank 12 for supplying and discharging cooling water 9 to and from the inside of the cavity body 11 is assembled below the base plate 10. A water supply system and a drainage system (not shown) are connected to the water tank 12.

That is, in general, the cavity 8 which needs an electric input to the excitation lamp 3 and needs to adopt a water-cooled structure is made of a material having relatively low rigidity such as synthetic resin having both insulation and corrosion resistance. Since this is adopted, the cavity main body 11 made of synthetic resin or the like is reinforced by the metal base plate 10 in substantially the same manner as the conventional cavity, so that distortion deformation can be suppressed.

A laser rod 2 is disposed at a center position in the width direction (vertical direction in FIG. 1) of the accommodation space secured in the cavity main body 11, and a pair of laser rods 2 are arranged along both right and left sides of the laser rod 2. Excitation lamps 3 are arranged.

Each of the laser rods 2 is inserted at its axial end into the base end of a rod holder 13 and held in a liquid-tight manner via an O-ring 14. This rod holder 13 is made of a base plate. It is fixed from the 10 side via a metal fixing block 15.

Further, the rod holder 1 is inserted through a laser light entrance / exit port 16 opened at the front and rear end faces of the cavity body 11.
Up to 3, the tip of the rod holder 13 is connected to an end of the rod holder 13 via an O-ring 17 by an optical path duct 18 which is inserted in a liquid-tight manner, and the optical path duct 18 is defined by components of the cavity body 11. A liquid-tight inner fitting is attached to the formed cylindrical portion via an O-ring 19.

Here, the O at the base end of the rod holder 13 is
The ring 14 is crushed through the inner rings 21 and 22 by tightening the lock ring 20 screwed to the distal end side of the rod holder 13 to the proximal end side, and externally fits on the end of the laser rod 2. It is designed to be attached.

The optical path duct 18 is formed so as to be inserted from the outside of the cavity main body 11 through the entrance / exit port 16 and connected to the rod holder 13, and a bush defining the entrance / exit port 16 is formed. The lock ring 24 screwed to the inner peripheral surface of the lock member 23 is held so as not to be pulled out to the outside by tightening.

In this embodiment, a pinhole-shaped small hole 25 is formed between the tip of the optical path duct 18 and a lock ring 24 for holding the optical path duct 18 so as not to be pulled out. The laser beam emitted from the axial end of the laser rod 2 is passed through the small hole 25 so as to have a required beam divergence angle. The laser beam in the outer portion is cut off to limit the beam diameter, so that good beam quality with high directivity can be maintained.

In the drawing, reference numeral 27 denotes a flow tube loosely fitted on the outer peripheral portion of the laser rod 2 and capable of transmitting the excitation light of the excitation lamp 3, and has flowed between the flow tube 27 and the laser rod 2. As shown in FIG. 2, the cooling water 9 passes through the periphery of the rod holder 13 and passes through the cooling water passage 15a below the fixed block 15 to reach the cooling water tank 12 from the cooling water hole 10a of the base plate 10, while the excitation lamp 3 The cooling water 9 flowing around passes through the cooling water passage 11a shown in FIG. 1 and the cooling water hole of the base plate 10 (not shown) to reach the cooling water tank 12, and the same flow as these. A channel configuration is also formed symmetrically at the end of the cavity 8 on the opposite side from the illustration, so as to form a water supply system for the cooling water 9.

If the aperture 26 is mechanically positioned with respect to the laser rod 2 and mounted in the cavity 8 as in the above-described embodiment, the aperture 2
Since the mechanical position accuracy of the laser rod 2 with respect to the laser rod 2 can be obtained in advance, an independent movable mechanism for the aperture 26 is unnecessary, and the aperture 26 can be used without adjustment when the cavity 8 is replaced. Becomes

In particular, as shown in this embodiment, the cavity body 11 is assembled on the metal base plate 10 and the aperture 26 is attached to the laser light entrance / exit port 16 opened at the front and rear end faces of the cavity body 11. In general, a low-rigidity cavity body 1 made of a synthetic resin or the like having both insulation and corrosion resistance
1 can be reinforced by the base plate 10 to suppress distortion deformation, so that the aperture 26 can be positioned with high accuracy with respect to the laser rod 2.

Since the laser rod 2 and the excitation lamp 3 housed in the cavity 8 can be cooled by the cooling water 9, for example, the thermal conductivity of the peripheral members such as the optical path duct 18 and the rod holder 13 can be reduced. By raising, the heat generated when the aperture 26 interferes with the extra laser beam can be indirectly removed by the cooling water 9 in the cavity 8, eliminating the necessity of newly providing a water cooling structure dedicated to the aperture 26. This makes it possible to achieve a significant reduction in equipment cost.

The solid-state laser cavity of the present invention is
It is needless to say that the present invention is not limited to the above-described embodiment, and that various changes can be made without departing from the spirit of the present invention.

[0026]

According to the solid-state laser cavity of the present invention described above, the aperture can be incorporated in the cavity and the mechanical position accuracy with respect to the laser rod can be obtained in advance, so that a movable mechanism having a complicated structure is unnecessary. The aperture can be used without adjustment when exchanging the cavity, and the heat generated when the aperture interferes with the extra laser light can be removed by the cooling water in the cavity. There is no need to provide a water cooling structure for use, and an excellent effect that the overall equipment cost can be significantly reduced can be achieved.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing an example of an embodiment of the present invention.

FIG. 2 is a view in the direction of arrows II-II in FIG.

FIG. 3 is a schematic plan view showing an example of a general solid-state laser oscillator.

[Explanation of symbols]

 2 Laser rod 3 Excitation lamp (Excitation light source) 8 Cavity 9 Cooling water 10 Base plate 11 Cavity main body 16 Inlet / outlet port 25 Small hole 26 Aperture

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Yoshihisa Yamauchi 3-1-1, Toyosu, Koto-ku, Tokyo Ishikawajima-Harima Heavy Industries, Ltd. Tokyo Engineering Center (72) Inventor Minoru Uehara 3-1-1, Toyosu, Koto-ku, Tokyo No. 15 Ishikawajima Harima Heavy Industries, Ltd. Tokyo Engineering Center (72) Inventor Keinosuke Maeda 7-2-14 Toyo, Koto-ku, Tokyo Ishikawajima System Technology Co., Ltd. F term (reference) 5F072 AK01 JJ05 JJ20 KK09 KK30 MM08 PP01 TT15 TT22

Claims (2)

[Claims] 1. A solid-state laser cavity configured to receive a laser rod made of a solid-state laser medium together with an excitation light source and to cool the laser rod and the excitation light source with cooling water, wherein the laser rod has an axial end. A cavity for a solid-state laser, wherein an aperture for restricting a beam diameter by passing a laser beam emitted from a portion through a small hole is mechanically positioned with respect to the laser rod. 2. A solid-state laser according to claim 1, wherein the cavity body is assembled on a metal base plate, and an aperture is attached to a laser light entrance / exit opening opened at front and rear end surfaces of the cavity body. cavity.