JP3132576B2 - Slab type solid-state laser device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high-power slab-type solid-state laser device for an Nd: YAG laser or the like.

[0002]

2. Description of the Related Art The slab-type fixed laser device described above incorporates a slab-type solid laser medium cut out from a rod such as an Nd: YAG laser and an excitation light source in a storage container through which a cooling medium flows. A laser oscillator is formed by combining resonator mirrors, and the structure and principle thereof are disclosed in, for example, JP-A-3-22579 previously proposed by the same applicant as the present invention. In addition, the applicant of the present invention has a configuration in which a laser light transmitting member facing a slanted end face of both ends of a laser medium with a minimum gap is provided in a laser light extraction portion of a storage container with respect to the slab type fixed laser device. It is proposed as Japanese Patent Application No. 2-324071.

Here, for example, an Nd: YAG laser is an yttrium aluminum garnet (abbreviated as YAG).
The crystal material of the above is a base material, and Nd ions are implanted as an active medium. The laser material is melted in a furnace, and a good-quality portion is removed from a rod of a single crystal material pulled up while growing a crystal by a pulling device. The laser medium is cut out to produce a slab-shaped laser medium. In the Nd: YAG laser manufactured as described above, it is difficult to obtain a large single crystal from the viewpoint of manufacturing technology, and currently available sizes from a manufacturer are 10 mm long, 27 mm wide, and 210 mm long. It is about.

On the other hand, the laser output of a solid-state laser device, particularly the oscillation output in continuous operation, is determined by the size of a laser medium incorporated in the device. By the way, in the above-mentioned solid-state laser device, one single-crystal laser medium is stored in a storage container for each device, and therefore, the laser output of one device naturally has a limit. Therefore, in particular, in response to a demand for a high-power laser device, a cascade-connected solid-state laser device using a plurality of laser oscillators connected in series has been proposed and has already been put to practical use. FIG. 3 shows this cascade-connected solid-state laser device. A plurality of solid-state laser oscillators 21 are arranged in series on a common frame 20 with their optical axes aligned, and total reflection is performed on both sides as mirrors for resonators. A mirror 22 and an output mirror 23 are provided. Each laser oscillator 21 has a single crystal solid laser medium 2 for each group.
4. The excitation light source and the like are incorporated in the storage container. Note that L indicates laser light and LO indicates laser output. With such a configuration, the laser output of the entire apparatus becomes substantially equal to the sum of the outputs of the laser oscillators 21 of each group, thereby obtaining a high-output laser apparatus.

[0005]

The cascade connection type laser device described above has the following problems. That is, (1) when a plurality of laser oscillators 21 are individually installed on the common gantry 20, the optical axes are accurately aligned between the solid-state laser medium 24 and the mirrors 22 and 23 of each laser oscillator 21. If the optical axis is slightly deviated, the power loss increases and a predetermined output characteristic cannot be obtained.
Moreover, the adjustment work of the optical axis alignment is extremely troublesome, and high-precision positioning requires much labor and time.
Even if such adjustments are made at the time of the factory shipment test, if the product is transported to the site, vibrations and the like are applied,
It is unavoidable that the installation position of each laser oscillator 21 with respect to 0 is slightly deviated, and therefore, the adjustment is required again at the installation site, which is extremely troublesome. (2) In addition, since the laser oscillators 21 as the components of the cascade connection type laser device are individually manufactured independently, the entire device becomes large and the total cost increases. It will be very expensive.

The present invention has been made in view of the above points, and has as its object to provide a high-power slab-type solid-state laser device having a small size, a compact structure, and excellent effects in handling. I do.

[0007]

According to the present invention, a slab-type solid laser medium, an excitation light source, and a laser beam transmitting member are incorporated in a storage container through which a cooling medium flows. A slab-type solid-state laser device configured by combining a resonator mirror with the slab-type solid-state laser device, wherein a plurality of slab-type laser media are arranged and stored in series in the same storage container with their optical axes aligned. In addition, it is assumed that slab-shaped light guide members are arranged in series in the storage container with their optical axes aligned with the laser media located on both ends of the plurality of laser media arranged in series, respectively, on opposite sides of the laser media.

According to the present invention, a slab in which a slab-shaped solid laser medium, an excitation light source, and a laser beam transmitting member are incorporated in a storage container through which a cooling medium flows, and a resonator mirror is combined with the slab-shaped solid laser medium. In the solid state laser device,
A slab-type solid-state laser device in which a plurality of slab-type laser media are stored and arranged in series in the same storage container with their optical axes aligned, and a holder for the laser medium is installed with the inner wall surface of the storage container as a mounting seat surface. The laser medium arranged in the storage container is positioned and fixed at a predetermined position via the holding tool, and the holding tool sandwiches the excitation light non-irradiation side surface of the laser medium from both sides via the heat insulating material. Shall be.

[0009]

According to the above construction, a plurality of solid-state laser media are arranged in series in a single storage container to irradiate excitation light. A laser output equivalent to the above is obtained. In addition, the slab-type light guide member provided with the optical axis aligned at both ends of the slab-type laser medium arranged in series is made of optical glass having high light transmittance, and has substantially the same cross-sectional shape as the laser medium,
It has a length determined according to the dimensions of the terminal fittings at both ends of the excitation light source lamp, and functions as a light guide path for relaying between the laser medium and the laser light transmitting member attached to the end face of the container. By incorporating such a light guide member in the container, the excitation light is applied to each laser medium while the light source lamp is arranged at the shortest distance to the laser medium without interference with the terminal fitting of the excitation light source lamp. Irradiation can be uniform.

On the other hand, the holder for the laser medium is provided with the inner wall surface of the storage container as a positioning reference plane, and the laser media arranged in series are individually positioned and fixed at predetermined positions via the holder. Here, the inner wall surface of the storage container is processed with high precision so as to form a uniform refrigerant passage for the laser medium, and by using this inner wall surface as a mounting reference surface, the optical axis of each laser medium is adjusted. Can be held in the correct position to match. Moreover, since the holder holds the non-excitation surface, which is not irradiated with the excitation light, to the slab-shaped laser medium via the heat insulating material from both sides, the holder becomes an obstacle to the excitation light. Each laser medium can be fixedly supported at a predetermined position with no fear and with the occurrence of an unreasonable temperature gradient inside the laser medium suppressed.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. FIG. 1 is a cross-sectional view of the entire slab-type fixed laser device, and FIG. 2 is a cross-sectional view taken along the line II-II of FIG.
In the drawing, reference numeral 1 denotes a storage container of a device configured as a liquid-tight closed container, and reference numeral 2 denotes a plurality (two in the illustrated example) of slab shapes arranged in series with the optical axis at the center in the storage container 1. A laser medium (cut out of a single crystal laser rod into a rectangular cross section); 3 is an excitation light source lamp arranged in parallel on the upper and lower sides of a laser medium 2 at the center; 4 is a reflector of the light source lamp 3; Reference numeral 5 denotes an ultraviolet light filter interposed between the light source lamp 3 and the laser medium 2, reference numeral 6 denotes a slab-shaped light guide member arranged in series with the optical axis on both sides of the laser medium 2 arranged in series, and reference numeral 7 denotes a light guide. Laser light transmitting members 8 and 9 serving as laser light extraction windows attached to the end plate 1a of the storage container 1 facing the end surface of the optical member 6, are provided on both sides of the storage container 1 so as to face the laser light transmission member 7. Total reflection mirror and output mirror for tuned resonator Reference numeral 10 denotes a holder for individually positioning and fixing the laser medium 2 and the light guide member 6 at predetermined positions, and supports both longitudinal ends of the laser medium 2 and the light guide member 6. . In addition, O is provided on each joint surface of the storage container 1 and the penetrating portion of each component incorporated in the storage container 1.
It is liquid-tightly sealed by a ring or the like.

In the above configuration, the cooling medium (pure water) flows through the cooling medium inlet and outlet (not shown) inside the storage container 1 as described below, and the laser medium 2, the excitation light source lamp 3, the reflector 4 is cooled to discharge the generated heat to the outside of the system. That is, the cooling medium flowing into the inlet side header chamber 1b of the storage container 1 in FIG. 2 flows therefrom into the space 1c partitioned between the laser medium 2 and the ultraviolet light filter 5, and further around the excitation light source lamp 3. After flowing through the space 1d, it flows so as to flow out through the outlet side header chamber 1e.

On the other hand, the excitation light source lamp 3 has a length corresponding to the total length of the two laser media 2 whose light emitting portions are arranged in series, and includes a housing container including terminal fittings 3a at both ends thereof. 1. The light guide members 6 arranged in series at the front and rear ends of the two laser media 2 are slab-shaped light guide members made of optical glass, and their cross-sectional shapes are the same as or slightly larger than the slab-type laser medium 2. The length is set to a size corresponding to the distance between the front and rear ends of the laser medium 2 and the laser light transmitting member 7. This light guide member 6
Functions as a light guide path for relaying between the laser medium 2 and the laser light transmitting member 7, and the laser light travels in a zigzag manner while repeating total reflection inside the light guide member 6.

As described above, the slab-shaped light guide member 6 having substantially the same cross-sectional shape as the laser medium 2 is provided inside the storage container 1, and the laser light transmission member 7 having the laser medium 2 and the end face of the storage container 1 attached thereto. , The light emitting portion of the light source lamp 3 is disposed close to the laser medium 2 without interference with the terminal fitting 3a of the excitation light source lamp 3, and the laser medium 2 can be uniformly irradiated with the excitation light over the entire excitation surface of the laser medium, thereby increasing the laser oscillation efficiency and the laser output.

Next, a detailed structure of the holder 10 for the laser medium 2 will be described. In FIG. 2, first, a cooling medium flow space 1 defined inside a storage container 1 surrounding a laser medium 2.
c is machined with high precision so that the inner wall surfaces on both sides thereof form a V-shaped groove. The V-shaped inner wall surface is used as a mounting seat surface, and each laser medium 2 is placed on both sides via a heat insulating material 11 here. A Y-shaped holder 9 having a bifurcated tip is provided facing each other so as to be sandwiched from the surface (the side surface on the non-excitation side not receiving the excitation light irradiation from the excitation light source lamp 3).
Here, one of the holders (the lower side in FIG. 2) has its base fixed to the storage container 2 via the through bolt 12 in a loose fit manner.
The other holder (upper side in FIG. 2) is tightened and fixed from behind by a tightening screw 13. In addition, the above-mentioned light guide member 6 is also fixed via a similar holder 10.

The inner wall surface of the storage container 1 which has been machined with high precision as described above is used as a mounting seat surface, and the laser media 2 and the light guide member 6 arranged in series on a reference surface via a holder 10 are arranged. In the support structure in which the non-excitation surfaces are individually held and fixed from both sides, the holder 10 does not become an obstacle to the excitation light irradiation on the excitation surface of the laser medium 2 and each laser medium 2 The members 6 can be correctly positioned and fixedly supported at positions where the optical axes coincide with each other.

[0017]

Since the slab-type solid-state laser device of the present invention is constructed as described above, the following effects can be obtained. (1) A plurality of single-crystal slab-type laser media are arranged in series in the same container with their optical axes aligned, and each laser medium is irradiated with excitation light. And a high output equivalent to that of the cascade connection type laser device. Furthermore, the number of required parts is smaller than that of a cascade-connected laser device in which a plurality of independent laser oscillators are arranged on a common base, and the device can be reduced in size, size, and manufacturing cost. In addition to this, the optical axes of the laser media do not easily deviate from each other due to vibration when transported from the factory to the installation site, and the handling reliability is greatly improved.

(2) Further, a slab-shaped light guide member is additionally provided at both ends of the laser media arranged in series, and a relay light guide path is provided between the laser medium and the laser light transmitting member mounted on the end face of the storage container. By adopting the formed structure, it is possible to uniformly radiate the excitation light to the entire excitation surface of each laser medium while disposing the light source lamp close to the laser medium without interference with the terminal fitting of the excitation light source lamp. Thereby, the efficiency of the laser device (ratio of laser output to lamp input) can be improved.

(3) Further, the inner wall surface of the refrigerant flow passage in the storage container which has been machined with high precision is used as a mounting seat surface, and the mounting seat surface is used as a reference surface for holding each laser medium via a holder. By adopting the support structure fixed at the position, the laser media arranged in series can be assembled with their optical axes correctly aligned. Here, since the holder has a heat-insulating support structure that sandwiches the non-excitation surface of the laser medium from both sides via the heat insulating material, the holder itself does not become an obstacle to the irradiation of the excitation light, and There is no improper temperature gradient inside the laser medium.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a configuration according to an embodiment of the present invention.

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

FIG. 3 is a configuration diagram of a conventional cascade connection type solid-state laser device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Storage container 2 Slab type solid laser medium 3 Excitation light source lamp 6 Slab type light guide member 7 Laser light transmission member 8 Total reflection mirror 9 Output mirror 10 Holder 11 Heat insulating material

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H01S 3/02-3/0979 H01S 3/23

Claims (2)

(57) [Claims] 1. A slab-type solid-state laser device comprising a slab-type solid-state laser medium, an excitation light source and a laser beam transmitting member incorporated in a storage container through which a cooling medium flows, and a resonator mirror combined therewith. A slab-type solid-state laser device in which a plurality of slab-type laser media are arranged and stored in series in the same storage container with their optical axes aligned, wherein each of the laser media located at both ends of the plurality of laser media in a series is arranged. A slab-type solid-state laser device in which a slab-type light guide member is arranged in series in a storage container with an optical axis aligned with a side of an anti-adjacent laser medium. 2. A slab-type solid-state laser device comprising a slab-type solid laser medium, an excitation light source and a laser beam transmitting member incorporated in a storage container through which a cooling medium flows, and a resonator mirror combined therewith. A slab-type solid-state laser device in which a plurality of slab-type laser media are arranged and arranged in series in the same storage container with their optical axes aligned, and a holder for the laser medium is installed with the inner wall surface of the storage container as a mounting seat surface. The laser medium arranged in the storage container is positioned and fixed at a predetermined position via the holder, and the holder holds the excitation light non-irradiation side surface of the laser medium from both sides via the heat insulating material. A slab-type solid-state laser device, characterized in that: