JP2000133863A - Solid-state laser - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a longitudinal single-mode laser which is easy of setup and adjustment and is of low noise. SOLUTION: A solid-state laser medium 6 and an aerospace type etalon 7 are stuck to each other by an adhesive 8, and reflecting coatings 13 and 15 for a resonator mirror and an output mirror are made at both its end faces. When exciting light is led in from outside the coating 13, a light of specified wavelength is amplified by a solid-state laser medium 6 and the etalon 7, and its one part permeates the coating 15 and is taken out to the outside. The interval between both etalon faces across a cavity can be narrowed substantially, and the etalon face can be made by the same vapor deposition process, so that a longitudinal single-mode laser which is high in selectivity of wavelength and low noise can be obtained. Moreover, since a resonator 1 is united, the setup and adjustment is vary much facilitated.

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 device that generates laser oscillation by introducing an externally applied pumping light from a semiconductor laser or the like into a resonator, and more particularly, operates in a so-called vertical single mode. The present invention relates to a solid-state laser device.

[0002]

2. Description of the Related Art A solid-state laser device using a semiconductor laser as excitation light is widely used not only for research purposes but also industrially because of its features such as low power consumption, small size, long life, and easy handling. It has become. FIG. 7 is a diagram showing a basic configuration of a resonator in a conventional general solid-state laser device. In this resonator 30, a resonator mirror 31
In addition, a reflection surface of the output mirror 32 is disposed so as to face, and a solid-state laser medium (for example, ruby, YAG, etc.) 33 for obtaining a resonance gain is provided therein. The pumping light is transmitted through the resonator mirror 31 and introduced into the resonator 30, and a laser beam is generated by repeating reflection between the mirrors 31 and 32 while light of a specific wavelength is amplified by the solid-state laser medium 33, Part of the output light is output mirror 32 as output light.
And is taken out.

In the solid-state laser device having the above-described configuration, the wavelength of the laser can be shortened by inserting a nonlinear optical crystal into the optical path inside the resonator 30 to generate a second harmonic. Laser devices that generate visible light such as green and blue light in this way are promising in a wide range of applications such as interference applications, optical pickup applications, and printing applications, and have been actively researched and developed in recent years.

In general, in this type of laser device, longitudinal multimode oscillation occurs inside the resonator as shown in the spectrum of FIG. 8 (one vertical spectrum in FIG. 8 is the longitudinal mode). Therefore, when the second harmonic is generated using the nonlinear optical crystal as described above, it is known that noise (generally called “green problem”) due to longitudinal mode competition is generated (for example, T . Bea
r, "Large-amplitude fluctuations due to longitudina
l mode coupling in diode-pumped intracavitydoubled
Nd: YAG laser ", J. Opt. Soc. Am. B3, pp 1175-1180
(1986)).

Various methods have been conventionally proposed to prevent such noise. For example, a method of rotating polarized light by inserting a quarter-wave plate into an optical path inside a resonator (for example, see M. Oka, S. Kubota, "Stable int
racavity doubling of orthogonal linearly polarized
modes in diode-pumped Nd: YAG ", Opt. Lett. 13, pp.
805-807 (1988)), a method of averaging and alleviating fluctuations due to longitudinal mode competition by increasing the number of oscillating longitudinal modes significantly, or a green resonator using a traveling-wave type ring resonator. Methods for avoiding the spatial hole burning itself, which is the cause of the problem, are known. Also, in order to oscillate inside the resonator in a single longitudinal mode, a method of inserting a flat etalon, which is an optical element having wavelength selectivity, inside the resonator or reducing the thickness of the solid-state laser medium A method of preventing only one longitudinal mode from entering a wavelength region where a resonance gain is obtained has been proposed.

[0006]

However, each of the above conventional methods has a problem. A method using a quarter-wave plate, a method of generating a number of longitudinal modes, or a method employing a ring resonator requires a large number of optical elements to be used, which makes it difficult to adjust the optical system, and requires time for assembly. And it takes time, resulting in poor productivity. Light loss (internal loss)
, The laser oscillation threshold value rises and the efficiency becomes worse, and furthermore, a large space is required, so that miniaturization is difficult.

[0007] In a method of achieving a single longitudinal mode by reducing the thickness of the solid-state laser medium, the absorption of the excitation light in the solid-state laser medium is deteriorated, the efficiency is reduced, and the laser output is reduced. Further, when the nonlinear optical crystal inside the resonator is irradiated with the excitation light not absorbed by the solid-state laser medium, the temperature thereof may rise and the operation of generating a harmonic may be unstable. Of course, since a thin solid-state laser medium is difficult to handle, it is easily damaged and has poor assemblability.

A flat solid etalon has an etalon surface at both end surfaces with a predetermined flat medium interposed therebetween, and only light contained in a specific wavelength region is reflected in a process of repeating reflection between the two etalon surfaces. It is taken out of the etalon and its properties depend on the thickness of the etalon (ie, the medium). Therefore, this thickness is determined in consideration of the longitudinal mode interval determined by the gain of the solid-state laser medium, the interval between mirrors forming the resonator, and the like.
In order for only one transmission peak of the etalon to exist in the wavelength region where the oscillation gain is high, it is necessary to reduce the thickness and increase the free spectral range (FSR). Then, although the interval between adjacent transmission peaks is widened and the oscillation stop band is widened, the half-width of the transmission peak is widened (that is, the transmission wavelength region is widened), and the selectivity of the longitudinal mode is deteriorated. Therefore, a mode hop that jumps from one vertical mode to another adjacent vertical mode occurs, or a plurality of vertical modes temporarily exist, which causes noise. Of course, an etalon having a small thickness deteriorates workability and makes it difficult to handle.

In order to improve the longitudinal mode selectivity, the half width of the transmission peak of the etalon can be narrowed by increasing the reflection finesse by appropriately coating the etalon end face. However, since such coating is performed in a different process for each side, the reflectivities of both sides are not the same, and it is difficult to sufficiently increase the reflection finesse.

When a plurality of solid etalons are used side by side, the longitudinal single mode oscillation is achieved by appropriately changing the thickness of each etalon without making one etalon too thin. Can be. However, in this case, the adjustment of the position of each etalon inside the resonator becomes very troublesome. In addition, the loss of light increases, resulting in a decrease in laser output.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and it is an object of the present invention to generate a low-noise longitudinal single-mode laser, to be small in size, and to facilitate assembly adjustment. An object of the present invention is to provide a certain solid-state laser device.

[0012]

According to a first aspect of the present invention, there is provided a solid-state laser device for generating laser oscillation by introducing externally applied pumping light into a resonator. Comprises at least one set of an incident-side reflecting surface and an output-side reflecting surface, a solid-state laser medium having a gain in a predetermined wavelength region, and an aerospace-type etalon having wavelength selectivity, and one end surface of the etalon and the solid-state etalon. It is characterized in that one end surface of the laser medium is bonded and integrated.

According to a second aspect of the present invention, there is provided a solid-state laser device for generating harmonics inside a resonator. Wherein the resonator comprises at least one set of an incident-side reflecting surface and an emitting-side reflecting surface, a solid-state laser medium having a gain in a predetermined wavelength region, and an optical element for generating harmonics. And an aerospace-type etalon having wavelength selectivity, wherein one end surface of the solid-state laser medium and one end surface of the optical element are bonded and integrated to both end surfaces of the etalon, respectively. That is, in this configuration, the etalon is integrated while being sandwiched between the solid-state laser medium and the optical element.

According to a third aspect of the present invention, there is provided a solid-state laser device for generating laser oscillation by introducing an externally applied pumping light into a resonator, wherein the resonator comprises at least one pair of an incident side reflecting surface and an emitting side reflecting surface. A solid-state laser medium having a gain in a predetermined wavelength region, an optical element for generating harmonics, and an aerospace-type etalon having wavelength selectivity. One of the end face and one end face of the optical element is bonded and integrated. In this configuration, it is preferable that one end face of the solid-state laser medium and one end face of the optical element are bonded, and the other end face of the optical element and one end face of the etalon are bonded.

In the solid-state laser devices according to the second and third aspects of the present invention, a nonlinear optical crystal can be generally used as an optical element for generating harmonics.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The aerospace type etalon referred to here is a two-plate medium having a so-called etalon surface formed on one end face, with an optically polished material sandwiched between both etalon faces. By adjusting them, the interval between the two etalon surfaces can be adjusted. That is, light incident from the end face of one flat medium is repeatedly reflected in the gap between the two etalon surfaces, and light having a wavelength corresponding to the interval selectively exits from the side opposite to the incident face.
For this reason, fine adjustment is possible as compared with the above-mentioned solid etalon, and in particular, the interval between the etalon surfaces can be easily reduced.

In the solid-state laser device according to the first aspect of the invention, the excitation light transmitted through the incident-side reflection surface and introduced into the resonator is applied to the solid-state laser medium, and light within a predetermined wavelength region is amplified. Also, as described above, the light is repeatedly reflected in the space of the aerospace type etalon, and only light having a specific wavelength passes. In the process of being repeatedly reflected between the incident-side reflection surface and the emission-side reflection surface, such amplification and wavelength selection are performed, and a portion of the light that has become a longitudinal single-mode laser passes through the emission-side reflection surface. Taken out.

In the solid-state laser devices according to the second and third aspects of the present invention, in the process of repeatedly reflecting light between the incident-side reflecting surface and the emitting-side reflecting surface, the second harmonic is produced by the same operation as in the first aspect. Is converted into a single longitudinal mode, and part of the light is transmitted through the reflecting surface on the emission side and extracted to the outside.

In the solid-state laser device according to the first to third aspects of the present invention, the solid-state laser medium and the aerospace etalon or an optical element for generating higher harmonic waves are bonded and integrated before the assembly and adjustment of the resonator. By doing so, it is possible to greatly reduce the labor for mounting components and adjusting the position when assembling the resonator.

In the solid-state laser device according to the first to third aspects of the present invention, the incident-side reflection surface is formed on the end surface of the solid-state laser medium opposite to the bonding surface of the aerospace etalon or the optical element for generating harmonics. A configuration with a coating can be adopted. In addition, the integrated component may have a configuration in which a coating for forming an output-side reflection surface is applied to an end surface opposite to the incident-side end surface. According to this, since the resonator including the incident-side reflecting surface and the output-side reflecting surface is integrated, further downsizing can be achieved and assembly adjustment is almost unnecessary.

Further, an appropriate optical element can be additionally provided inside the resonator. Specifically, by providing an element for controlling the polarization of laser light, a laser having a specific polarization can be extracted. Further, by providing a Q-switch element for controlling laser oscillation, a pulsed laser can be extracted.

When the end faces of the solid laser medium, the aerospace type etalon, and the optical element for generating harmonics facing the respective bonding surfaces are planes perpendicular to the optical axis of the solid laser medium, light is generated at this interface. May be undesirably reflected to cause a composite resonator phenomenon due to return light. Therefore, in order to prevent this, the solid laser medium facing the bonding surface, the aerospace type etalon, one or both end surfaces of the harmonic generation optical element, or the reflection surface facing the void of the aerospace type etalon is required. It is preferable to form them at a predetermined angle from a plane perpendicular to the optical axis.

[0023]

According to the solid-state laser devices according to the first to third aspects of the present invention, an aerospace type etalon is used inside the resonator, and one end face of the etalon and an end face of the solid-state laser medium or an optical element such as a nonlinear optical crystal. Since the end face is bonded and integrated, it is easy to assemble the resonator, and the assembling adjustment time can be greatly reduced. Further, it is possible to reduce the size of the resonator and obtain an inexpensive longitudinal single-mode solid-state laser device with low noise output.

[0024]

[Embodiment 1] FIG. 1 is a configuration diagram of a resonator of a solid-state laser device according to an embodiment (hereinafter, referred to as "embodiment 1") of the first invention. The resonator 1 includes a resonator mirror 2 having a coating 3 that transmits the excitation light with low loss and highly reflects the oscillated light on the concave surface, and transmits a part of the light and the oscillated light. An output mirror 4 provided with a highly reflective coating 5 on the concave surface is disposed facing the inside, and a solid-state laser medium 6 is provided inside the resonator 1 so as to face the resonator mirror 2. Solid laser medium 6
Is attached to one end surface of an aerospace type etalon 7 using an adhesive 8 made of resin. The aerospace type etalon 7 is formed by forming an etalon surface 11 on one end surface of each of two plate-shaped media 10 by a method such as vapor deposition, and sandwiching an optically polished spacer 12 between the etalon surfaces 11. The interval between the two is set to a predetermined length. This interval is appropriately determined in consideration of the longitudinal mode interval of the resonator 1 (that is, the interval between the resonator mirror 2 and the output mirror 4), the resonance gain of the solid-state laser medium 6, and the like.

If the solid-state laser medium 6 and the aerospace etalon 7 are adhered to each other before assembling the resonator 1, the two can be handled as an integral part when the assembly of the resonator 1 is adjusted. it can. Therefore, the number of assembling steps can be reduced, and the position can be easily adjusted.

In the aerospace type etalon 7, since the etalon surfaces 11 can be formed on the two flat mediums 10 by the same vapor deposition process, the reflectances of the two etalon surfaces 11 can be made equal. The advantages of this are as follows besides simply reducing the number of manufacturing steps.

Now, consider a configuration in which a solid-type etalon is bonded between a solid-state laser medium and a nonlinear optical crystal. For example, when a solid-state laser medium is Nd: YAG (Y ₃ Al ₅
O ₁₂ -Nd ^3+), a nonlinear optical crystal in KNb0 _3, quartz solid type etalon (without facet coating, refractive index 1.45)
When using, Nd: the refractive index of the YAG and KNb0 ₃ respectively as 1.8,2.2, dissipation within each element is assumed not by Fresnel reflection, Nd: YAG
1.16% in between the etalon, the reflectivity 4.22% in between KNb0 ₃ and the etalon. Therefore, the reflection finesse of the solid etalon is 0.478 (per one round trip reflection) according to a well-known calculation formula.

On the other hand, in the aerospace type etalon used in the solid-state laser device of the present invention, since both etalon surfaces have an interface with air, the reflectance by Fresnel reflection is 3.37% in each case. Therefore, the reflection finesse is 0.597, which is 2 times larger than that of the solid etalon.
It is about 0% higher. In the solid type etalon, the finesse may be further reduced depending on the material and thickness of the adhesive layers on both sides. The larger the finesse, the better the wavelength selectivity and the less the loss, so in the aerospace etalon,
Longitudinal single mode oscillation described later can be performed more stably, which is advantageous in terms of laser output.

The above-structured solid-state laser device operates as follows. Excitation light provided from outside the resonator 1 (for example, a semiconductor laser) passes through the resonator mirror 2 and irradiates the solid-state laser medium 6. Since the solid-state laser medium 6 has a gain in a specific wavelength region, light included in the wavelength region is amplified, and light outside that region is attenuated. The light introduced into the aerospace type etalon 7 is applied to the spacer 1
The light is repeatedly reflected between the etalon surfaces 11 opposed to each other with respect to 2 and emits light in a single longitudinal mode included in a predetermined wavelength region from a surface opposite to the incident surface. While the light is repeatedly reflected between the coating 3 of the resonator mirror 2 and the coating 5 of the output mirror 4, a specific longitudinal single mode light gains a large gain, and a part of the light passes through the output mirror 4. And go outside.

Since there is a space between the aerospace etalon 7 and the output mirror 4 in the resonator 1 according to the first embodiment, the space (at the position 9 in FIG. 1) of the oscillation laser light If an element for controlling polarization (for example, a polarization element) is inserted, a linearly polarized light output can be obtained. If a Q-switch element is inserted to control this element, a pulsed laser can be obtained. These additional elements may be inserted in the space between the resonator mirror 2 and the solid-state laser medium 6, but from the viewpoint of loss of pumping light, the position indicated by the reference numeral 9 is more preferable.

[Embodiment 2] FIG. 2 is a structural view of a resonator of a solid-state laser device according to another embodiment of the first invention (hereinafter referred to as "embodiment 2"). In this resonator 1, one end face of the solid-state laser medium 6 and one end face of the aerospace etalon 7 are adhered by an adhesive 8 as in the first embodiment. Instead, the opposite end face of the solid-state laser medium 6 is provided with a coating 13 corresponding to a resonator mirror, and the opposite end face of the aerospace etalon 7 is provided with a coating 15 corresponding to an output mirror. The oscillation operation of the solid-state laser device according to the second embodiment is the same as that of the first embodiment. However, since the resonator mirror and the output mirror are integrated, the labor for assembly and adjustment can be further reduced, and the size can be reduced. It is.

[Embodiment 3] FIG. 3 is a structural diagram of a resonator of a solid-state laser device according to another embodiment (hereinafter, referred to as "embodiment 3") of the first invention. In the configuration of the second embodiment, since the interface of each element is perpendicular to the optical axis, there is a possibility that a composite resonance phenomenon due to return light may occur inside the resonator 1. The third embodiment aims at suppressing the occurrence of the complex resonance phenomenon, and is directed to the end face of the solid-state laser medium 6 and the adhesive 8.
Aerospace type airron 7 opposed to the end face across
Has a wedge angle α on its end face. By making the wedge angles α of both end surfaces the same, the attachment becomes easy. In addition, both etalon surfaces 11 of the aerospace type etalon 7 have a wedge angle β. In this way, by shifting the angle of the interface of each element from the angle of the surface formed by the coatings 13 and 15 on both ends, the optical path of the return light is shifted to avoid the composite resonator phenomenon. Note that the wedge angles α and β may be the same. The wedge angles α and β can be determined as appropriate. However, as the wedge angles α and β increase, the loss of light at the interface increases.

[Embodiment 4] FIG. 4 is a configuration diagram of a resonator of a solid-state laser device according to an embodiment (hereinafter, referred to as "embodiment 4") of the second invention. This solid-state laser device has a resonator 1
A laser having a short wavelength is obtained by converting a fundamental wave of longitudinal single mode oscillation generated internally into a second harmonic. Therefore, instead of forming the reflective coating 15 on the right end face of the aerospace etalon 7 in the configuration of the second embodiment, a non-linear optical crystal 20 is adhered using an adhesive 8 and the opposite of the non-linear optical crystal 20 is used. A coating 15 corresponding to an output mirror is formed on the end face. The nonlinear optical crystal 20 converts the fundamental wave into a second harmonic having a half wavelength when the light passes. Therefore, in the configuration of the fourth embodiment, since the fundamental wave is longitudinal single mode oscillation inside the resonator 1, a green problem does not occur, and it is possible to extract a longitudinal single mode harmonic laser light with extremely low noise. .

In the configuration of the fourth embodiment, the positions of the aerospace etalon 7 and the nonlinear optical crystal 20 can be interchanged. Also, as in the third embodiment, the adhesive 8
An appropriate wedge angle may be provided at the interface of each optical element with.

[Embodiment 5] FIG. 5 is a structural view of a resonator of a solid-state laser device according to an embodiment of the third invention (hereinafter referred to as "Embodiment 5"). In this solid-state laser device, the positions of the aerospace etalon 7 and the nonlinear optical crystal 20 in the configuration of the fourth embodiment are interchanged, and the flat end surface of the condensing lens 21 is formed on the left end surface of the solid-state laser medium 6. It is attached to the outside of the coating 13 using an adhesive 8. In FIG. 5, the excitation light irradiated from the left side is condensed by the condensing lens 21 and irradiates the active region of the solid-state laser medium 6 (the region where a predetermined laser oscillation is generated by resonance gain).

Usually, in order to efficiently introduce the excitation light into the resonator 1 in the configuration of the fourth embodiment, it is necessary to separately provide a convex lens for condensing outside the coating 13 on the incident side. According to the configuration of the fifth embodiment, the lens can also be integrated with the resonator, so that further downsizing and ease of assembly adjustment can be achieved. The condensing lens 21 need not be a spherical lens, but may be an aspheric lens or a rod lens.

[Embodiment 6] FIG. 6 is a structural view of a resonator of a solid-state laser device according to another embodiment of the third invention (hereinafter referred to as "Embodiment 6"). This solid-state laser device is an example in which the third invention is applied to a traveling wave tube type resonator. That is, the resonator mirror 2 provided with the reflection coatings 3 and 5 and the output mirror 4 are spaced apart from each other at a predetermined angle as shown in FIG. 6, and an optical isolator 22 for limiting the oscillation direction is provided therebetween. Provided. In addition, the nonlinear optical crystal 20 is sandwiched between the solid-state laser medium 6 having one end face formed at the Brewster angle and the aerospace etalon 7 formed at one end face at the Brewster angle, and each adhesive face is adhered with the adhesive 8. The integrated part is placed at a predetermined position.

In this configuration, the pump light introduced into the resonator 1 from the outside of the resonator mirror 2 circulates as indicated by the arrow in FIG. Oscillation is generated, converted into a second harmonic by the nonlinear optical crystal 20, and a part of the light is transmitted through the output mirror 4 and extracted to the outside. By integrating the solid-state laser medium 6, the nonlinear optical crystal 20, and the aerospace type etalon 7, not only the labor required for the assembly adjustment is reduced, but also the space for disposing each component is small, which is advantageous for miniaturization. is there.

[Other Modifications] For example, in the configuration of the first embodiment, if the refractive index of the material of the solid-state laser medium 6 and the refractive index of the material of the aerospace type etalon 7 (the plate-like medium 10) are large, if both are large. Reflection of light at the interface increases and light loss increases. That is, it is desirable that the refractive indexes of the two optical elements sandwiching the adhesive are the same as much as possible. Therefore, in the construction of Examples 1 to 4, and YAG the material of the plate-like medium 10 and Y ₃ Al ₅ O ₁₂ (without doping), the material of the solid-state laser medium 6 doped with Nd in Y ₃ Al ₅ O ₁₂ By doing so, it is good to make the refractive index of both the same.

Further, at least one end face of the solid-state laser medium 6 or the etalon 7 with the adhesive interposed therebetween may be coated with an appropriate coating for matching the refractive indexes, and thereafter, both may be bonded.

In the above embodiment, an adhesive made of resin is used for bonding the optical elements. However, the adhesive is not limited to this as long as high transmittance can be obtained.

When an excitation light having a relatively large energy is used to obtain a high output laser, the excitation light generates heat in a solid-state laser medium and the like, and this heat is applied to the etalon and the nonlinear optical crystal via an adhesive. The temperature may increase due to transmission. In such a case, if the bonded elements have different coefficients of thermal expansion, distortion may occur and the oscillation efficiency may be deteriorated, as well as damage may be caused. Therefore, for example, it is possible to cool the whole part by fixing it on a pedestal made of a Peltier element, or to arrange a water channel in close contact with the periphery of the equipment and cool it using cooling water. Good.

Further, as in the first to sixth embodiments, the whole is molded with a resin or the like after the optical elements are bonded to each other, so that the handling is further facilitated. If a resin having good heat conductivity is used for the mold, it is advantageous in terms of heat dissipation.

Further, for example, when it is desired to obtain particularly sharp wavelength selectivity, a plurality of aerospace type etalons may be arranged in parallel.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a resonator of a solid-state laser device according to an embodiment of the first invention.

FIG. 2 is a configuration diagram of a resonator of a solid-state laser device according to another embodiment of the first invention.

FIG. 3 is a configuration diagram of a resonator of a solid-state laser device according to another embodiment of the first invention.

FIG. 4 is a configuration diagram of a resonator of the solid-state laser device according to one embodiment of the second invention.

FIG. 5 is a configuration diagram of a resonator of a solid-state laser device according to an embodiment of the third invention.

FIG. 6 is a configuration diagram of a resonator of a solid-state laser device according to another embodiment of the third invention.

FIG. 7 is a basic configuration diagram of a resonator of a conventional general solid-state laser device.

FIG. 8 is a spectrum at the time of longitudinal multimode oscillation by the solid-state laser device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Resonator 2 ... Resonator mirror 3, 5, 13, 15 ... Coating 4 ... Output mirror 6 ... Solid-state laser medium 7 ... Aerospace type etalon 10 ... Plate-like medium 11 ... Etalon surface 12 ... Spacer 8 ... Adhesive

Claims (3)

[Claims] 1. A solid-state laser device for generating laser oscillation by introducing excitation light supplied from the outside into a resonator, the resonator comprising at least one set of an incident-side reflecting surface and an emitting-side reflecting surface, and a predetermined wavelength. A solid-state laser medium including a solid-state laser medium having a gain in a region and an aerospace-type etalon having wavelength selectivity, wherein one end face of the etalon and one end face of the solid-state laser medium are bonded and integrated to form a solid. Laser device. 2. A solid-state laser device for generating laser oscillation by introducing excitation light supplied from the outside into a resonator, wherein the resonator comprises at least one set of an incident side reflecting surface and an emitting side reflecting surface, and a predetermined wavelength. A solid-state laser medium having a gain in a region, an optical element for generating harmonics, and an aerospace type etalon having wavelength selectivity, and one end face of the solid-state laser medium and the optical element on both end faces of the etalon. A solid-state laser device wherein one end surfaces of the elements are bonded and integrated. 3. A solid-state laser device for generating laser oscillation by introducing excitation light supplied from the outside into a resonator, wherein the resonator comprises at least one set of an incident side reflecting surface and an emitting side reflecting surface, and a predetermined wavelength. A solid-state laser medium having a gain in a region, an optical element for generating harmonics, and an aerospace type etalon having wavelength selectivity, and one end face of the etalon, one end face of the solid-state laser medium or A solid-state laser device, wherein one of the end faces of the optical element is bonded and integrated.