JPH0799352A - Laser oscillator - Google Patents

Abstract

PURPOSE:To provide a laser oscillator having high cooling capacity in high oscillation frequency regardless of the compact size as a device. CONSTITUTION:A cavity 3 containing exciting lamps and a laser rod is internally installed on almost the central position of a cylindrical casing 2 while cooling fins 7 are formed by outer sidewall indentedly made around the cavity 3 inside the cylindrical casing 2 as well as air flow paths in the cylindrical casing axial direction are formed passing through the gaps between these cooing fins 7. Furthermore, the heat exchangers 7 composed to circulate cooling water between the cavity 3 and the outer sidewall are integrally provided while a cooling fan 6 blowing toward the heat exchangers 7 side is also provided on the rear part of the cylindrical casing 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laser oscillating device having a small size and a high oscillation efficiency.

[0002]

2. Description of the Related Art For example, in the field of medical treatment, a lot of treatments for heating and cauterizing a living tissue of a subject by irradiating the living tissue of the subject with the laser light are often performed. When using laser light, there is little damage to living tissue,
In addition, since there are advantages such as less bleeding, the development of this laser device is rapidly progressing.

The laser light oscillating section of such a laser device is constructed so as to emit laser light by exciting a YAG laser rod with an excitation lamp, and the laser light oscillated from the laser rod is reflected by a resonance mirror. After being resonated / amplified and further condensed by a condenser lens, it is guided by an optical fiber and irradiated onto the affected area by a laser probe at the tip. in this case,
The laser light output is adjusted by changing the current value to the excitation lamp.

In the case of this type of laser oscillation device, if the current required to emit a desired laser output is constantly supplied to the excitation lamp, the amount of heat generated from the excitation lamp increases and the efficiency significantly decreases. Therefore, for example, Japanese Patent Laid-Open No. 5-
In Japanese Patent No. 115491, as shown in FIG. 3, a laser oscillator 40, a cooling tank 41, and a pump 4 are provided.
2, there is disclosed a device in which a circulation line system 45 having a filter 43 and a heat exchanger 44 is formed and cooling water is circulated for cooling. In this case, the cooling capacity is adjusted by controlling the rotation speed of the cooling fan 46 based on the cold water temperature information from the temperature sensor 48.

[0005]

However, in the case of the above-mentioned cooling device, the size of the cooling tank, the capacity of the pump, the capacity of the heat converter, etc. are generally dependent on the setting of the planned cooling capacity. It tends to be large and large in terms of equipment, and since cooling water is sent to the laser oscillator after cooling with a heat converter in the middle of the circulation path, a cooling response time lag easily occurs. Also, the cavity is likely to be unevenly cooled, and it is difficult to control the cooling of the laser oscillator with high accuracy.

Therefore, a main object of the present invention is to provide a laser oscillation device having a high cooling efficiency, which has a high cooling capacity and a cooler excellent in cooling responsiveness in spite of its small size. To do.

[0007]

The above object is to provide a cavity for accommodating an excitation lamp and a laser rod inside a cylindrical casing at a substantially central position of its cross section.
Inside the cylindrical casing, a large number of cooling fins are formed integrally with the cavity surrounding the periphery of the cavity by an outer wall that is processed into an uneven shape, and the cooling fins pass through the gaps. Is provided with a heat exchanger configured so that an air flow path in the axial direction of the tubular casing is formed and a cooling liquid is circulated between the cavity and the outer wall, while the rear portion of the tubular casing is provided. The problem can be solved by providing a cooling fan that blows air toward the heat converter side.

Further, in this case, it is desirable to cover the resonance mirrors arranged at the front and rear parts on the optical axis with the laser rod in between and the condenser lens arranged at the front part on the optical axis with a dust cover.

[0009]

In the present invention, the cavity in which the excitation lamp and the laser rod are housed, that is, the laser oscillator is housed in the cylindrical casing. A heat converter having the above-described shape is provided around the cavity integrally with the cavity, and a cooling fan is provided on the rear side in the tubular casing. In this way, since the cooler is housed in the tubular casing, the entire apparatus becomes compact.

Further, since the heat converter is integrally provided around the cavity and the cooling fan is provided with the tubular casing as the air guide passage, the total amount of the blown air contributes to the cooling effectively and the heat Since the cooling water cooled by the converter directly acts on the cavity, it is possible to secure a high cooling capacity in spite of the compact size of the device, and because the cooling response is excellent, the temperature of the cavity is kept high. Easy to manage.

Further, since the cooling fan is provided on the coaxial line behind the cavity, the cavity is uniformly cooled in the circumferential direction, so that the error of the optical axis deviation due to the thermal expansion of the cavity is small and the oscillation efficiency is lowered. Can be prevented.

[0012]

EXAMPLES The present invention will be described in detail below based on examples.
In FIG. 1, a laser oscillation device 1 according to the present invention has a laser oscillation portion internally provided in a cylindrical casing 2. In the cylindrical casing 2, a laser rod 4 is placed at a substantially central position of the cross section, and two excitation lamps 5 and 5 are arranged in parallel on both sides of the laser rod 4. The laser rod 4 and the excitation lamps 5 and 5 are both housed in a cavity (hollow body) whose cross section is spectacle-shaped.

A rear side resonance mirror 11 is housed in a dust cover 16A on the rear side of the laser rod 4 on the optical axis, and a front side is housed in a dust cover 16B on the front side thereof. The resonance mirror 12 is arranged. Further, in front of the front side resonance mirror 12, a cylindrical dust cover tube 13 is interposed in the middle, and the dust cover tube 13 is housed in a lens holder 17 screwed at the tip of the dust cover tube 13 to form a condenser lens 14. It is arranged. Although not shown, an opening / closing shutter can be provided on the laser optical axis to control the oscillation operation of the laser light. Further, the sectional shape of the tubular casing 2 is not limited to the circular shape shown in the embodiment, and an appropriate shape such as a square shape or a polygonal shape can be used.

For the irradiation of laser light, flash light is emitted from the excitation lamp 4 by a driving power source (not shown), and the energy of this flash light is reflected on the inner surface of the cavity 3 and absorbed by the laser rod 4 for excitation. The laser light emitted from the laser rod 4 is resonated by the rear resonance mirror 11 and the front resonance mirror 12, and is emitted from the front resonance mirror 12 in an amplified state. The emitted laser light is focused by the condensing lens 14
The light is focused by the laser beam and is incident on the optical fiber 15, and is sent to the laser probe at the tip and is irradiated on the affected area.

By the way, in the device of the present invention, a heat converter 7 is provided in the tubular casing 2 so as to surround the cavity 3 and integrally with the cavity 3, and a rear side of the tubular casing 2 is provided. On the side, a cooling fan 6 that blows air to the heat converter side is provided. The heat converter 7 has a large number of fins 7a, 7a, ...
The air passages A, A ... Are formed in the axial direction of the cylindrical casing 2 passing through the gaps a, 7a ... And the cooling water supplied between the cavity 3 and the outer wall is the cooling fan 6.
It is designed to be uniformly cooled in the circumferential direction by the air blown from.

In the illustrated example, the fins 7a, 7a ...
The outer wall is processed to have a concavo-convex shape in the axial direction of the tubular casing 2, and as shown in FIG. In addition to being secured, the air blown from the cooling fan 6 installed on the rear side of the casing 2 is passed to the front side. In this embodiment, the rear side resonance mirror 11, the front side resonance mirror 12 and the condenser lens 14 are covered with dust covers 16A, 16B and 13 because the dust from the cooling fan 6 is blown. This is to protect these from.

On the other hand, the cooling water is circulated by a water supply pump 10 which is provided in the middle of the circulation passage 8 formed around the heat converter 7. 10
Is a water tank for storing cooling water.

Since the laser oscillator of the present invention is small and has high oscillation efficiency, it can be adopted as a particularly suitable one when incorporated in a robot.

..

As described in detail above, according to the present invention, a laser having a high cooling efficiency is provided with a cooler having a high cooling capacity and an excellent cooling response, although the apparatus is small. It can be an oscillator.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of a laser oscillator according to the present invention.

FIG. 2 is a sectional view taken along line II-II in FIG.

FIG. 3 is a diagram showing a cooling structure of a conventional laser oscillator.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Laser oscillation device, 2 ... Cylindrical casing, 3 ... Cavity, 4 ... Laser rod, 5 ... Excitation lamp, 6 ...
Cooling fan, 7 ... Heat converter, 7a ... Fin, 9 ... Water tank, 10 ... Water pump, 11 ... Rear resonance mirror, 12
... front resonance mirror, 14 ... condenser lens, 15 ... optical fiber

Claims (2)

[Claims] 1. A cylindrical casing at substantially the center of its cross section,
A cavity accommodating the excitation lamp and the laser rod is provided internally, and in the tubular casing, a plurality of outer walls are formed integrally with the cavity surrounding the cavity so as to form an uneven shape. The cooling fins are formed, and the air passages in the axial direction of the cylindrical casing are formed through the gaps of the cooling fin group.
A cooling device that includes a heat exchanger configured to circulate a cooling liquid between the cavity and the outer wall, and that blows air toward the heat converter side at a rear portion of the tubular casing. A laser oscillating device having a fan. 2. The laser oscillation device according to claim 1, wherein the resonance mirrors arranged at the front and rear portions on the optical axis with the laser rod interposed therebetween and the condenser lens arranged at the front on the optical axis are covered with a dust cover.