JPH07283466A - Solid laser - Google Patents

Abstract

PURPOSE:To provide a solid laser having a circulation channel for passing cooling water for deionizing and cooling water for maintaining a laser bolt cooling water for deionizing and cooling water for maintaining laser rod at a prescribed temperature by one circulating path. CONSTITUTION:A solid laser, which cools a solid laser medium provided in a laser head 1 and an excitation lamp for optically pumping this solid laser medium, is provided with a circulating path 14, which circulates cooling water to the head 1 and cools the solid laser medium and the excitation lamp, an ion-exchange resin unit 24, which deionizes the cooling water provided in this path 14, and a first heat exchanger 22, which cools the cooling water flowing in this unit 24 to a prescribed temperature or lower. Moreover, the solid laser is provided with a heating heater 26, which heats the cooling water, which flows in the laser head provided on the downstream side of the unit 24, to a prescribed temperature or higher.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solid-state laser medium provided on a laser head and an exciting lamp for optically exciting the solid-state laser medium by cooling water.
The device.

[0002]

2. Description of the Related Art Generally, a solid-state laser device is designed to generate laser light by optically exciting a solid-state laser medium provided in its laser head with an excitation lamp.
The temperature rises significantly between the optically excited solid-state laser medium and the excitation lamp to which a high current is input. Therefore, the solid-state laser medium and the excitation lamp are cooled to prevent early heat loss thereof.

In the case of an alexandrite laser as a solid-state laser apparatus, it is required to control the temperature of a solid-state laser medium to be cooled to 90 ° C. in order to operate the apparatus efficiently. .

On the other hand, the excitation lamp that optically excites the solid laser medium is cooled in the state of being submerged in the cooling water due to the structure of the solid laser device, so that the cooling water has an electric conductivity of, for example, 300K. Cooling water deionized to a sufficiently low value, such as ohms / cm, is used. The cooling water is passed through an ion exchange resin unit provided with an ion exchange resin for deionization.

By the way, it is difficult for the ion exchange resin to deionize efficiently and surely unless the temperature of the cooling water is 50 ° C. or lower due to its temperature characteristics. That is, the temperature of the cooling water flowing through the ion exchange resin unit for cooling the excitation lamp and the cooling water for cooling the solid laser medium may be different.

Therefore, in the prior art, for example, Japanese Patent Laid-Open No. 60-2 is used.
As shown in Japanese Patent No. 39075, cooling water for cooling the excitation lamp and cooling water for cooling the solid laser medium are
It circulates through independent circulation paths, and the temperature of the cooling water is controlled separately in each circulation path.

However, according to such a conventional structure, it is necessary to control the temperature of each cooling water independently.
Since three independent circulation paths are required, this not only causes an increase in the size of the apparatus, but also causes an increase in cost due to the complicated structure. In addition, since the two circulation paths of the cooling water have to be liquid-tightly separated in the laser head, the structure of the laser head may be complicated.

[0008]

As described above, the temperature required for the deionized cooling water for cooling the excitation lamp and the temperature required for the cooling water for cooling the laser medium are different from each other. In this case, the laser head had to be provided with two independent circulation paths, which sometimes led to a complicated and large-sized apparatus.

The present invention has been made based on the above circumstances, and an object thereof is to cool the cooling water having a temperature suitable for deionization in one circulation path and the solid laser medium. Another object of the present invention is to provide a solid-state laser device which can obtain cooling water having different temperatures.

[0010]

The present invention described in claim 1 is a solid-state laser medium provided in a laser head and a solid-state laser for cooling an excitation lamp for optically exciting the solid laser medium. In the laser apparatus, a circulation path for circulating cooling water in the laser head to cool the solid laser medium and the excitation lamp, and an ion exchange resin unit provided in the circulation path for deionizing the cooling water. A first heat exchanger for cooling the cooling water flowing into the ion-exchange resin unit to a predetermined temperature or less, and cooling water flowing into the laser head provided downstream of the ion-exchange resin unit above a predetermined temperature. And a heating means for heating the solid laser device.

According to a second aspect of the present invention, there is provided a solid laser medium provided in a laser head and the solid laser medium.
In a solid-state laser device that cools an excitation lamp that optically excites a laser medium, a circulation path that circulates cooling water in the laser head to cool the solid-state laser medium and the excitation lamp,
An ion exchange resin unit provided in this circulation path for deionizing the cooling water, a first heat exchanger for cooling the cooling water flowing into the ion exchange resin unit to a predetermined temperature or lower, and an ion exchange resin unit Heating means provided on the downstream side for heating the cooling water flowing into the laser head to a predetermined temperature or higher, and a part of the cooling water from the laser head to the heating means without passing through the ion exchange resin unit. It is characterized in that it is provided with a bypass path for inflowing.

[0012]

According to the invention described in claim 1, the cooling water flowing into the ion exchange resin unit is cooled by the first heat exchanger to a temperature suitable for ion exchange, and the ion exchange resin unit performs ion exchange. The cooling water exchanged and flowing into the laser head is heated to a temperature suitable for cooling the solid laser medium by the heating means.

According to the invention described in claim 2, the first
By bypassing a part of the cooling water flowing into the second heat exchanger into the second heat exchanger, the flow rate of the high-temperature cooling water flowing into the first heat exchanger is reduced to the ion exchange resin unit. The temperature of the inflowing cooling water can be surely made lower than a predetermined temperature, and the temperature of the cooling water supplied to the laser head can be surely controlled.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. The first embodiment of the present invention shown in FIGS. 1 and 2 comprises a laser head 1 of a solid-state laser device. This ray
The head 1 has a main body 2 as shown in FIG. 2, and a cooling space 3 is formed in the main body 2. The cooling space 3 is provided with an elliptic cylindrical light collecting mirror-4.

A solid-state laser medium 5 for an alexandrite laser is arranged at one focus position of the light collecting mirror-4, and the solid-state laser medium 5 is optically excited at the other focus position. An excitation lamp 6 is arranged.

Both ends of the solid laser medium 5 are liquid-tightly supported by one end of a support tube 7. Each support tube 7
Is fluid-tightly inserted and supported in a pair of support holes 8 formed in the main body 2 with one end communicating with the cooling space 3 and the other end opened to the outside. A high-reflecting mirror 9 is disposed at the other end of one supporting tube 7 so as to face it, and an output mirror that forms an optical resonator with the high-reflecting mirror 9 at the other end of the other supporting tube 7. 11 are arranged facing each other.

When a high voltage is applied to the excitation lamp 6 to generate a discharge, the solid laser medium 5 is photoexcited by the discharge to generate a laser beam L. The laser light L is repeatedly reflected and amplified by the high-reflecting mirror 9 and the output mirror 11, and when the intensity reaches a predetermined level or higher, the laser light L is oscillated and output from the output mirror 11. .

The main body 2 has an inlet 12 and an outlet 13 for cooling water which communicate with the cooling space 3. The inlet 12 and the outlet 13 are connected to a middle portion of the circulation path 14 through which the cooling water circulates. Pure water is used as the cooling water circulating in the circulation path 14.

The circulation path 14 has a first heat exchanger 22.
Is provided. The first heat exchanger 22 has a first coil 21 into which the cooling water flowing out from the outlet 13 of the laser head 2 flows. This first heat exchanger 22
Exchanges heat with the cooling water flowing through the first coil 21 (cooling)
A second coil 23 for flowing a cooling medium such as city water is provided.

The cooling water that has undergone heat exchange in the first heat exchanger 22 and flows out of the first coil 21 flows into the ion exchange resin unit 24. This ion exchange resin unit 2
No. 4 has an ion exchange resin, and deionizes the cooling water flowing into it to make it sufficiently low in electrical conductivity. At this time, the effective operating range of the ion exchange resin unit 24 is 50.
Since it is below ℃, the cooling water from the laser head 1 is cooled to below 50 ℃ in the first heat exchanger 22 as described later.

The cooling water deionized by the ion exchange resin unit 24 is heated by a heating tank 25 which constitutes heating means.
Flow into. A heating heater 26 is provided in the heating tank 25.
Is provided. This heating heater 26 is a control device 27.
The cooling water that has been energized by the drive signal from the and flows into the heating tank 25 is heated.

The temperature of the cooling water in the heating tank 25 is detected by the first sensor 28. The detection signal of the first sensor 28 is input to the control device 27. The control device 27 compares the temperature detected by the first sensor 28 with the temperature set in the control device 27, and controls the energization of the heating heater 26 based on the comparison. It has become.

The set temperature set in the controller 27 is 60 to 99 ° C., which is a temperature suitable for operating the solid laser medium 5 of the alexandrite tracer efficiently, and 90 ° C. in this embodiment. Has become. Therefore,
The heating heater 26 provided in the heating tank 25 heats the cooling water flowing therein to 90 ° C.

A circulation pump 31 is connected to the outflow side of the heating tank 25, and the circulation water is circulated in the circulation passage 14 by the circulation pump 31. A 15 micron mesh cotton filter 33 is provided between the circulation pump 31 and the inlet 12 of the laser head 1. The cotton filter 33 removes dust contained in the cooling water and supplies the cooling water having a high purity to the laser head 1.

A bypass pipe 35 is branched from the circulation path 14 from the inflow side of the first coil 21 of the first heat exchanger 22. This bypass pipe 35 is connected to the first control valve 3
It is connected to the first coil 38 of the second heat exchanger 37 via 6. The first control valve 36 controls the ratio of the cooling water that flows to the first heat exchanger 22 and the second heat exchanger 37.

First coil 3 of the second heat exchanger 37
The cooling water flowing into 8 exchanges heat with the cooling medium flowing through the second coil 39 and flows into the heating tank 25. A second control valve 41 for controlling the inflow amount of the cooling medium is provided on the inflow side of the second coil 39.

The above-mentioned first control valve 36 and second control valve 41
Is the heating tank 25 detected by the first sensor 28.
The opening degree is set by a control signal from the control device 27 based on the temperature of the cooling water inside.

The controller 27 detects the temperature of the cooling water in the vicinity of the inlet 12 of the laser head 1 and the temperature of the cooling water in the vicinity of the outlet 13. The detection signal from the third sensor 43 is input. The detection signals from these sensors 42 and 43 are feedback based on the detection signals from the first sensor 28 for controlling the heating heater 6, the first control valve 36 and the second control valve 41. Used for control.

Next, the operation of the solid-state laser device having the above structure will be described. When the circulation pump 32 is operated, the cooling water circulates in the circulation path 14. The cooling water circulating in the circulation path 14 is cooled to 50 ° C. by the first heat exchanger 22, flows into the ion exchange resin unit 24 and is deionized, and is then reheated by the heating heater 26 in the heating tank 25. -The laser rod 5 in the laser head 1 is heated to a temperature capable of maintaining 90 ° C and flows into the laser head 1.

The heating temperature of the cooling water by the heating heater 26 is controlled by the control device 27 to the heating heater 26 based on the temperature of the cooling water detected by the first sensor 28 provided in the heating tank 25. It is performed by controlling the energization of. That is, the temperature of the cooling water is controlled by the heating heater 26 to 90 ° C., which is a temperature suitable for cooling the laser rod 5.

On the other hand, when the laser rod 5 is overheated by the excitation lamp 6 and the temperature of the cooling water flowing out from the laser head 1 becomes too high, the cooling water is passed through the first heat exchanger 22. However, depending on its capacity, it may not be possible to cool the ion-exchange resin unit 24 to 50 ° C. or lower.

In such a case, when the detection signal from the third sensor 43 for detecting the temperature of the cooling water flowing out from the laser head 1 is input to the control device 27, this control device 2
Reference numeral 7 controls the openings of the first control valve 36 and the second control valve 41.

That is, the first control valve 36 is opened at a predetermined opening according to the temperature of the cooling water detected by the third sensor 43, and a part of the cooling water that has been overheated by the laser head 1 is partially removed. It flows through the bypass pipe 35 to the second heat exchanger 37.
As a result, the flow rate of the cooling water flowing to the first heat exchanger 22 decreases, so that the cooling water is cooled to 50 ° C. or less by the first heat exchanger 22 and the ion exchange resin unit 2
4 can be supplied.

On the other hand, the high-temperature cooling water flowing through the second heat exchanger 37 is heat-exchanged here and flows into the heating tank 25. In the second heat exchanger 37, the cooling water is cooled to a temperature suitable for maintaining the solid laser rod 5 of the laser head 1 at 90 ° C, for example, 90 ° C, and then flows into the heating tank 25. In that case, the opening degree of the second control valve 41 is controlled by the control device 27, and the flow rate of the cooling medium flowing through the second coil 39 of the second heat exchanger 37 is controlled. The temperature of the cooling water flowing into the heating tank 25 through the first coil 38 of the heat exchanger 37 is controlled.

That is, by providing the second heat exchanger 37 in the bypass pipe 35, the temperature of the cooling water returning from the laser head 1 to the first heat exchanger 22 is too high, and this first heat exchange is performed. Even if the heat exchange capacity of the vessel 22 is exceeded, by partially bypassing the second heat exchanger 37, the ion exchange resin unit 24 is operated within the operating range of 50 ° C. The following cooling water can be supplied.

On the inflow side of the laser head 1, the temperature of the cooling water is detected by the second sensor 42. This second
When the temperature of the cooling water detected by the sensor 42 of FIG. 2 is deviated from the temperature of maintaining the solid laser medium 5 at 90 ° C., the heating heater 26 and the first control valve are controlled by the control device 27. A feedback signal is output to the control valve 36 and the second control valve 41 to control them. Therefore, the cooling water flowing into the laser head 1 is reliably controlled to a predetermined temperature, that is, a temperature suitable for maintaining the laser rod 5 at 90 ° C.

By flowing a part of the cooling water to the bypass pipe 35 and supplying it to the laser head 1 without passing through the ion exchange resin unit 24, the cooling water is not deionized, but it is a heating tank. At 25, the cooling water is supplied from the first heat exchanger 22 through the ion exchange resin unit 24 to the laser head 1 after being mixed with the deionized cooling water, so that the cooling water is insulated from the excitation lamp 6. Can be maintained.

FIG. 3 shows a second embodiment of the present invention. In this embodiment, the same parts as those in the first embodiment are designated by the same reference numerals and the description thereof will be omitted. In other words, in the second embodiment, the bypass pipe 35 is not provided with the second heat exchanger 37, and the outflow side of the first control valve 36 of the bypass pipe 35 is directly connected to the heating tank 25. did.

Further, when the detection signal of the third sensor 43 is input to the control device 27, the first control valve 3 is thereby activated.
Only the opening degree of 6 is feedback controlled.

According to such a configuration, the bypass pipe 35
The cooling water bypassed to the heating tank 2 is in a high temperature state.
5 where it is heated to 50 ° C. by the first heat exchanger 22.
The temperature is lowered by mixing with cooling water cooled below.

Therefore, the temperature of the cooling water in the heating tank 25 is controlled by the heating heater 26.
Since the heating is controlled to a temperature suitable for cooling, the laser head 1 can be supplied with cooling water capable of cooling the laser rod 5 to an optimum temperature as in the first embodiment.

That is, even if the bypass pipe 35 is not provided with the second heat exchanger 37 shown in the first embodiment, the temperature of the cooling water flowing into the ion exchange resin unit 24 and It is possible to control the temperature of the cooling water flowing into the laser head 1 to a predetermined temperature.

[0043]

As described above, according to the present invention, even when the cooling water is circulated in one circulation path, the temperature at which the cooling water flows into the ion exchange resin unit is set to the ion exchange resin unit. Can be reliably deionized by cooling to a temperature within the operating range of, and the solid laser medium can be cooled and maintained at a temperature higher than the operating range of the ion exchange resin unit.

Therefore, the circulation path for circulating the deionized cooling water and the circulation path for the cooling water for cooling and maintaining the solid laser medium at a predetermined temperature do not have to be separate, so that the structure of the apparatus is simplified. Can be small.

[Brief description of drawings]

FIG. 1 is a schematic view of the overall configuration of a solid-state laser device showing a first embodiment of the present invention.

FIG. 2 is a sectional view of the laser head.

FIG. 3 is a schematic diagram of an overall configuration of a solid-state laser device showing a second embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Laser head, 5 ... Solid laser medium, 6 ... Excitation lamp, 14 ... Circulation path, 22 ... First heat exchanger, 24 ... Ion exchange resin unit, 25 ... Heating tank, 26 ... Heating heater , 27 ... control device, 28 ... first sensor, 35 ... bypass pipe, 42 ... second sensor, 43 ... third sensor.

Claims (8)

[Claims] 1. A solid-state laser device for cooling a solid-state laser medium provided on a laser head and an excitation lamp for optically exciting the solid-state laser medium, wherein cooling water is circulated through the laser head. A circulation path for cooling the solid laser medium and the excitation lamp, an ion exchange resin unit provided in the circulation path for deionizing the cooling water, and cooling water flowing into the ion exchange resin unit at a predetermined temperature or lower. A solid body comprising: a first heat exchanger for cooling the cooling water and a heating means provided downstream of the ion exchange resin unit for heating the cooling water flowing into the laser head to a predetermined temperature or higher. Laser device. 2. A solid laser device for cooling a solid laser medium provided on a laser head and an excitation lamp for optically exciting the solid laser medium, wherein cooling water is circulated through the laser head. A circulation path for cooling the solid laser medium and the excitation lamp, an ion exchange resin unit provided in the circulation path for deionizing the cooling water, and cooling water flowing into the ion exchange resin unit at a predetermined temperature or lower. A first heat exchanger for cooling the cooling water, heating means provided downstream of the ion exchange resin unit for heating the cooling water flowing into the laser head to a predetermined temperature or higher, and cooling water from the laser head. And a bypass passage for letting a part of the gas flow into the heating means without passing through the ion exchange resin unit. 3. The heating means has a heating tank and a heating heater provided in the heating tank, and the heating heater detects a temperature of cooling water in the heating tank. The solid-state laser device according to claim 1 or 2, wherein the solid-state laser device is controlled by a control means to which a detection signal from the device is input. 4. The solid-state laser apparatus according to claim 2, wherein the bypass passage is provided with a second heat exchanger for adjusting the temperature of the cooling water flowing into the heating means. . 5. The temperature of the cooling water on the inflow side and the temperature of the outflow side of the laser head are respectively detected by sensors, and the detection signals are fed back to the control means. Solid state laser device. 6. A cooling water flow path is provided with a first control valve for adjusting a flow rate of the cooling water flowing to the first heat exchanger and the second heat exchanger. Claim 4
The solid-state laser device described. 7. A second control valve for controlling the flow rate of the cooling medium is provided in the pipeline of the cooling medium for exchanging heat with the cooling water flowing into the second heat exchanger. The solid-state laser apparatus according to claim 3, wherein the control valve is controlled together with the heating heater by the control means. 8. The temperature of the cooling water on the inflow side and the temperature of the outflow side of the laser head are respectively detected by sensors, and the detection signals are fed back to the control means. Solid state laser device.