JP4096137B2 - Laser oscillator - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to a laser oscillator, and more particularly to a laser oscillator including an excitation member that reflects laser light in a zigzag manner.
[0002]
[Prior art]
Conventionally, a pair of excitation members arranged with their reflecting surfaces facing each other, a reflecting mirror and an output mirror arranged facing each other on the optical axis of the laser light alternately reflected zigzag by the reflecting surfaces, There are known ones provided with laser means for injecting excitation laser light into a resonator space constituted by a mirror and an excitation member (Japanese Patent Laid-Open Nos. 8-162717 and 10-107365). ).
[0003]
[Problems to be solved by the invention]
However, in both of the above-mentioned publications, the inlet for receiving the excitation laser beam is provided between the excitation member and the reflection mirror, and between the excitation member and the output mirror.
For this reason, the optical axis of the excitation laser beam that enters the resonator space from the introduction port must coincide with the optical axis of the laser beam extracted from the output mirror, which is complicated and laborious to adjust. There are disadvantages.
In addition, conventionally, in order to efficiently make the excitation laser beam enter the resonator space from both the introduction ports, the excitation laser beam is collimated and introduced using optical parts (lens, fiber). As a result, the laser oscillator is expensive.
In view of such circumstances, the present invention provides the optical axis of the excitation laser beam incident from the laser means and the optical axis of the laser beam output from the output mirror in comparison with a laser oscillator having a conventional excitation member. It is an object of the present invention to provide an inexpensive laser oscillator that eliminates the need for complicated adjustment work for adjustment and omits optical system components for collimating excitation laser light.
[0004]
[Means for Solving the Problems]
That is, the invention according to claim 1 is the excitation member having the reflecting surfaces arranged to face each other, the reflecting mirror arranged to face each other on the optical axis of the laser light reflected alternately zigzag by the reflecting surface, and the output In a laser oscillator comprising: a mirror; and a laser unit that makes excitation laser light incident in a resonator space composed of the mirror and the excitation member.
The excitation member is composed of a plurality of excitation members alternately and intermittently disposed on opposing bases, and the base exposed between the excitation members is notched to be excited in the resonator space. An introduction port for introducing laser light is provided.
Further, the invention according to claim 2 is an excitation member in which the reflecting surfaces are arranged to face each other, a reflecting mirror arranged to face each other on the optical axis of the laser light that is alternately reflected in a zigzag manner on the reflecting surface, and an output In a laser oscillator comprising: a mirror; and a laser unit that makes excitation laser light incident in a resonator space composed of the mirror and the excitation member.
Each of the pumping members is composed of a single pumping member that is continuous along the laser beam reflection path, and the pumping laser beam is introduced into the resonator space by cutting off the non-reflective portion of the pumping member. Introducing the inlet.
[0005]
[Action]
According to the above-described configuration, the excitation laser light introduced into the resonator space from the introduction port is reflected in a zigzag manner by the pair of excitation members, the reflection mirror, and the output mirror that constitute the resonator space, and resonates. In addition, the laser light that has been amplified and reaches a predetermined output can be output from the output mirror.
Further, the introduction port can be appropriately provided in the base exposed between the excitation members and the non-reflective portion of the excitation member, so that the total area of the introduction port can be increased as compared with the conventional laser oscillator. .
Therefore, it is not necessary to make the optical axis of the excitation laser beam incident in the resonator space coincide with the optical axis of the laser beam output from the output mirror, so that the conventional complicated adjustment of the optical axis is omitted. In addition, by increasing the total area of the introduction port, it is possible to reduce the cost of the laser oscillator by omitting conventionally used optical components.
[0006]
【Example】
The present invention will be described below with reference to the illustrated embodiments. In FIG. 1, reference numeral 1 denotes a laser oscillator that amplifies and outputs a pumping laser beam L incident from a semiconductor laser (not shown) as a laser means to a predetermined output.
The laser oscillator 1 includes an upper first substrate (base) 2, a lower second substrate (base) 3, and an upper first substrate 2 that are arranged in parallel in a vertical direction on a frame (not shown). A square first solid-state laser medium 4 as an excitation member disposed on the end face with a space slightly larger than the dimension of one side of itself along the reflection path of the laser beam L ′, and a second lower side laser beam. The upper end surface of the substrate 3 is disposed so as not to overlap the first solid-state laser medium 4 with a space slightly larger than the size of one piece of itself along the reflection path of the laser light L ′. The second solid laser medium 5 having a square shape as a pumping member and the left and right sides of the two substrates 2 and 3 are disposed so that the opposite slope is inclined with respect to the first solid laser medium 4 on the leftmost side. The reflection mirror 7 is disposed on the right side of the two substrates 2 and 3 and is obliquely Is provided obliquely with respect to the second solid-state laser medium 5 on the rightmost side, and the reflecting mirror 7 and the output mirror 8 face each other on the optical axis of the laser beam L ′. . The first solid-state laser medium 4, the second solid-state laser medium 5, the reflection mirror 7, and the output mirror 8 form a resonator space that resonates the excitation laser light L.
[0007]
The first substrate 2 and the second substrate 3 include a copper plate (heat sink) 10 and a sapphire plate 11 that is bonded to the copper plate 10 and transmits the excitation laser beam l. Solid laser media 4 and 5 are joined. In the present embodiment, the sapphire plate 11 is bonded to the copper plate 10, but the present invention is not limited to this, and any material that transmits the excitation leather light L such as quartz may be used. In the present embodiment, the first solid-state laser medium 4 and the second solid-state laser medium 5 use Nd: YVO _{4 in} which Nd (neodymium) is added as an active ion to a YVO ₄ (yttrium vanadate) crystal. : Reflected surfaces 4a and 5a provided with a light reflecting coating that totally reflects the laser beam L 'on the back surface of YVO ₄ , that is, the sapphire plate 11 side. The reflecting surfaces 4a and 5a are parallel to each other in accordance with both solid-state laser media 4 and 5 that are parallel to each other.
In this embodiment, since Nd: YVO ₄ is used, a semiconductor laser that emits excitation laser light L having a wavelength of 800 nm is used. Note that, for example, Yb (ytterbium) or the like may be used instead of the Nd. In that case, the wavelength of the excitation laser beam L must be changed as appropriate.
[0008]
Thus, in this embodiment, a square is introduced by intermittently cutting the copper plate 10 of the first substrate 2 located between the first solid-state laser medium 4 and the first solid-state laser medium 4 that are spaced apart from each other, that is, above the second solid-state laser medium 5. An opening 12 is formed, and the excitation laser light L that has passed through the introduction port 12 and the sapphire plate 11 is set to enter the resonator space, specifically, the second solid-state laser medium 5. The copper plate 10 of the second substrate 3 positioned below the medium 4 is intermittently cut to form a square introduction port 13, and the excitation laser light L that has passed through the introduction port 13 and the sapphire plate 11 is converted into a resonator space, Specifically, it is set so as to be incident on the first solid-state laser medium 4.
At this time, the excitation laser light L radiated from the semiconductor laser is made incident without passing through the optical system components, and the excitation laser light L is different from the optical axis of the laser beam L ″ output from the output mirror 8. It is
[0009]
According to the configuration described above, the excitation laser light L incident on the first solid-state laser medium 4 and the second solid-state laser medium 5 is absorbed by Nd: YVO ₄ and becomes laser light L ′. The light L ′ is reflected by the reflecting surfaces 4a and 5a and travels while diffusing toward the other side.
Specifically, a part of the laser light L ′ reflected by the leftmost first solid-state laser medium 4 is incident on the reflection mirror 7 and the leftmost second solid-state laser medium 5, and the center first A part of the laser light L ′ reflected by the solid-state laser medium 4 is incident on the leftmost and central second solid-state laser medium 5 and further reflected by the rightmost first solid-state laser medium 4. A part of 'enters the second laser medium 5 at the center and the rightmost side.
On the other hand, a part of the laser beam L ′ reflected by the leftmost second solid-state laser medium 5 is incident on the leftmost and central first solid-state laser medium 4, and the central second solid-state laser medium. A part of the laser beam L ′ reflected by 5 is incident on the first and rightmost first solid-state laser medium 4 and further reflected by the second solid-state laser medium 5 on the rightmost side. This part is incident on the rightmost first solid-state laser medium 5 and output mirror 8.
As understood from this result, the laser light L ′ reflected by the first solid-state laser medium 4, the second solid-state laser medium 5, the reflection mirror 7 and the output mirror 8 is as shown in FIG. The laser beam L ′ continues in a zigzag manner, and is resonated between the first solid-state laser medium 4, the second solid-state laser medium 5, the reflection mirror 7, and the output mirror 8, that is, in the resonator space, and has a predetermined output. The laser beam L ′ that has reached is output from the output mirror 8 as a laser beam L ″.
By the way, in the conventional laser oscillator, since the introduction port is provided between the excitation member and the reflection mirror and between the excitation member and the output mirror, the optical axis of the incident excitation laser light is taken out from the output mirror. The laser oscillator must be aligned with the optical axis of the laser beam to be adjusted, and the adjustment is complicated, and the optical system parts are used to efficiently introduce the excitation laser beam from both inlets. However, if the excitation laser beam L is made incident through the inlets 12 and 13 provided in the first substrate 2 and the second substrate 3 as described above, it is complicated as in the prior art. The adjustment work of the optical axis can be made unnecessary, and if a large number of inlets 12 and 13 are provided, there is no need to use optical parts as in the prior art, so that the laser oscillator 1 can be configured at low cost.
[0010]
In the above embodiment, the reflecting surfaces 4a and 5a of the laser media 4 and 5 are arranged in parallel to each other. However, the angle of the reflecting surfaces 4a and 5a facing each other is such that the optical axis of the laser beam L ′ is the diffraction limit. It is possible to tilt to a certain angle.
In the above-described embodiment, the same number of inlets 12 and 13 as the first solid-state laser medium 4 and the second solid-state laser medium 5 are provided, but the present invention is not limited to this and may be less. In the embodiment, the excitation laser light is incident on both the first solid-state laser medium 4 and the second solid-state laser medium 5, but the present invention is not limited to this, and may be incident on only one of them. Good.
Further, in the present embodiment, the square laser media 4 and 5 are intermittently provided, but the present invention is not limited to this, and the laser media 4 and 5 may be continuous along the reflection path of the laser light L. In this case, the non-reflective portions of the laser media 4 and 5 as well as the substrates 2 and 3 must be cut out.
Furthermore, in the present embodiment, the excitation member is the solid laser medium 4 or 5, but the present invention is not limited to this, and a surface emitting semiconductor laser element may be used. In this case, the surface emitting semiconductor laser element is used. It is necessary to use a conductive substrate that conducts current.
[0011]
【The invention's effect】
As described above, according to the present invention, it is possible to eliminate the need for complicated adjustment of the optical axis as compared with the prior art, and to obtain an effect that the laser oscillator can be made inexpensive.
[Brief description of the drawings]
FIG. 1 is a side view showing an embodiment of the present invention.
2 is a perspective view of a first substrate 2 and a first solid-state laser medium 4. FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Laser oscillator 4 ... 1st solid-state laser medium 5 ... 2nd solid-state laser medium 7 ... Reflection mirror 8 ... Output mirror 12 ... Inlet 13 ... Inlet

Claims (4)

Exciting members arranged with their reflecting surfaces facing each other, reflecting mirrors and output mirrors arranged facing each other on the optical axis of the laser light that is alternately reflected in a zigzag manner on the reflecting surfaces, and the mirror and the pumping device In a laser oscillator comprising a laser means for injecting excitation laser light into a resonator space composed of members,
The excitation member is composed of a plurality of excitation members alternately and intermittently disposed on opposing bases, and the base exposed between the excitation members is notched to be excited in the resonator space. A laser oscillator comprising an introduction port for introducing laser light. Exciting members arranged with their reflecting surfaces facing each other, reflecting mirrors and output mirrors arranged facing each other on the optical axis of the laser light that is alternately reflected in a zigzag manner on the reflecting surfaces, and the mirror and the pumping device In a laser oscillator comprising a laser means for injecting excitation laser light into a resonator space composed of members,
Each of the pumping members is composed of a single pumping member that is continuous along the laser beam reflection path, and the pumping laser beam is introduced into the resonator space by cutting off the non-reflective portion of the pumping member. A laser oscillator characterized in that an introduction port is formed. 3. The laser oscillator according to claim 1, wherein the introduction port is closed by a transmission member that transmits the excitation laser beam. It said excitation member, a laser oscillator according to any one of claims 1, characterized in that a solid-state laser medium according to claim 3.

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