JP2004006975A - Solid state laser amplifier and solid state laser - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a solid state laser amplifier and a solid state laser for generating a high output high quality laser beam stably with high efficiency through a simple arrangement at low costs. <P>SOLUTION: The solid state laser amplifier comprises a solid state element 3 containing an active solid state medium, a flow tube 20 passing a refrigerant for cooling the solid state element 3, a condenser 8 having an inner diffuse reflection surface disposed around the solid state element 3 to hold the flow tube 20 while clamping directly, a pumping light source 4 disposed on the outside of the condenser and emitting a light 40 for pumping the solid state element 3, and an opening made through the condenser 8 in order to guide the pumping light 40. <P>COPYRIGHT: (C)2004,JPO

Description

The present invention relates to a solid-state laser amplifying apparatus and a solid-state laser apparatus capable of stably generating a high-output, high-quality laser beam with high efficiency with an inexpensive configuration.

FIG. 13 is a side view showing a conventional solid-state laser device (for example, see Non-Patent Document 1). In the figure, 1 is a reflection mirror, 2 is a partial reflection mirror, 3 is a solid-state element including an active solid medium, and in the case of a yag laser, Nd: YAG (Nd: Yttrium @ Aluminum @ Garnet) doped with Nd as an active solid medium. is there. Reference numeral 4 denotes an excitation light source, for example, a semiconductor laser mainly containing GaAlAs, 5 a power supply for driving the excitation light source 4, 6 a condenser lens, and 7 a laser generated in a laser resonator constituted by mirrors 1 and 2. The beam 10 is an optical thin film for making the reflection mirror 1 totally reflect the laser beam 7 and totally transmitting the light of the semiconductor laser, 40 is light emitted from the semiconductor laser 4, and 70 is a partially reflecting mirror The laser beam extracted to the outside by 2 and 100 is a base.

The conventional solid-state laser device is configured as described above, and the light of the semiconductor laser 4 turned on by the power supply 5 is introduced from the end face of the solid-state element 3 by the condenser lens 6, and is excited to excite the laser amplification medium. And Spontaneous emission light generated from the laser amplifying medium is amplified while reciprocating between the resonators constituted by the mirror 1 and the mirror 2, and becomes a laser beam 7 having good directivity. The light is emitted outside as a laser beam 70.

Solid-State Laser Laser Engineering, Springer-Verlag, pp. 119-120

In the conventional solid-state laser device as described above, since the light of the semiconductor laser is guided to the solid-state element from the end face, the vicinity of the end face is strongly excited, and when a semiconductor laser having a large output is used to generate high output, Light intensity distribution was generated in the solid-state device, and the beam shape was broken. For this reason, it was not possible to generate a high-output high-quality beam with the conventional configuration.

Furthermore, in the conventional solid-state laser device, since the absorption rate of the solid-state device depends on the wavelength of the semiconductor laser, it was necessary to adjust the wavelength of the semiconductor laser to the absorption wavelength of the solid-state device for stable operation. FIG. 14 shows the relationship between the wavelength of the semiconductor laser and the pumping efficiency, taking an Nd: YAG laser as an example. For stable operation while keeping the pumping oscillation efficiency constant, select a semiconductor laser having a center wavelength of 810 nm. It is necessary to further control the temperature. This not only complicates the configuration of the device, but also lowers the yield in the manufacture of semiconductor lasers, raises the price, and raises the problem of an expensive device.

Furthermore, in the conventional solid-state laser device, the light of the semiconductor laser is condensed by a lens at one point of the solid-state element and is excited. There is also a problem that the position fluctuates, the oscillation is not stable, and even when the semiconductor laser is replaced due to its life, fine adjustment of the position and angle of the semiconductor laser is required.

The present invention has been made to solve such a problem, and uniformly excites a solid-state element from the side to obtain a high-quality, high-output laser amplification medium, and the wavelength of the excitation light source changes. Solid-state laser amplifying device that has a constant oscillation efficiency, stably oscillates even with mechanical vibration, has a small output fluctuation, and can stably generate a high-output and high-quality laser beam. And to obtain a solid-state laser device at a low cost with a simple configuration. It is another object of the present invention to provide a solid-state laser amplifying device and a solid-state laser device in which the excitation light source can be easily replaced.

A solid-state laser amplifying device according to claim 1 of the present invention is a solid-state device including an active solid medium, a flow tube for flowing a cooling medium for cooling the solid-state device, and disposed so as to surround the solid-state device. And a condenser for directly or indirectly sandwiching and holding the flow tube, disposed outside the condenser, an excitation light source that emits excitation light for exciting the solid-state element, and the condenser And an opening for guiding the excitation light.

The solid-state laser amplification device according to claim 2 of the present invention is a solid-state device including an active solid medium, a flow tube for flowing a cooling medium for cooling the solid-state device, and a solid-state device. A light collector configured by a reflection surface, a side plate holding both ends of the light collector, an excitation light source that is disposed outside the light collector, and emits excitation light for exciting the solid-state element, and provided in the light collector And an opening for guiding the excitation light.

The solid-state laser amplifying device according to claim 3 of the present invention is a solid-state device including an active solid medium, a flow tube through which a cooling medium for cooling the solid-state device flows, and a solid-state device. A light collector configured with a reflection surface, a base holding the light collector, disposed outside the light collector, an excitation light source that emits excitation light for exciting the solid-state element, and provided in the light collector, An aperture for guiding the excitation light is provided.

A solid-state laser amplifying device according to claim 4 of the present invention is a solid-state device including an active solid medium, a concentrator arranged so as to surround the solid-state device, and an inner surface formed of a diffuse reflection surface, and a concentrator. An excitation light source that is arranged outside and emits excitation light that excites the solid-state element, an opening that is provided in the condenser, and guides the excitation light, and emits light from the excitation light source around the opening or a solid. An optical element for transferring light to the periphery of the element by total internal reflection is provided.

According to a fifth aspect of the present invention, there is provided a solid-state laser amplifying device according to any one of the first to third aspects, wherein the light emitted from the excitation light source is totally internally reflected to the periphery of the opening or the solid-state element. Is provided with an optical element for transferring data.

A solid-state laser amplifying device according to claim 6 of the present invention is a solid-state device including an active solid medium, a concentrator disposed so as to surround the solid-state device, and an inner surface formed of a diffuse reflection surface, and a concentrator. An excitation light source that is disposed outside and emits excitation light that excites the solid-state element, an opening that is provided in the condenser and guides the excitation light, and an optical element that emits light from the excitation light source is totally reflected. A thin film is provided on a side surface, and has an optical element for transferring the emitted light to the periphery of the opening or the periphery of the solid state device.

The solid-state laser amplifying device according to claim 7 of the present invention is different from the solid-state laser amplifying device according to any one of claims 1 to 3 in that an optical thin film on which light emitted from an excitation light source is totally reflected is provided on a side surface. And an optical element for transferring the emitted light to the periphery of the opening or the periphery of the solid-state element.

A solid-state laser amplifying device according to claim 8 of the present invention is a solid-state device including an active solid medium, a concentrator arranged so as to surround the solid-state device, and an inner surface formed of a diffuse reflection surface, and a concentrator. An excitation light source that is disposed outside and emits excitation light that excites the solid-state element; an excitation light source that is provided in the condenser and guides the excitation light; and a refractive index distributed in a lens shape, the excitation light source And an optical element for transferring light emitted from the device to the periphery of the opening or the periphery of the solid-state device.

The solid-state laser amplifier according to claim 9 of the present invention is different from the solid-state laser amplifier according to any one of claims 1 to 3 in that the solid-state laser amplifier has a refractive index distributed in a lens shape and emits light from the excitation light source. The optical device includes an optical element for transmitting the emitted light to the periphery of the opening or the periphery of the solid state device.

１０ Further, a solid-state laser amplifier according to claim 10 of the present invention is one wherein the optical element according to any one of claims 4 to 9 is integrated with an excitation light source.

A solid-state laser amplifying device according to claim 11 of the present invention is a solid-state device including an active solid medium, a concentrator arranged so as to surround the solid-state device, and an inner surface formed of a diffuse reflection surface; An excitation light source that emits excitation light that is arranged outside and that excites the solid-state element, includes a plurality of openings provided in the condenser, and guides the excitation light, and the positions of the plurality of openings are respectively , When viewed from the axial direction of the solid-state element.

According to a twelfth aspect of the present invention, a solid-state laser amplifying device according to any one of the first to tenth aspects further comprises a plurality of openings for guiding excitation light, Each position of the opening changes at least at one position when viewed from the axial direction of the solid-state element.

The solid-state laser amplifying device according to claim 13 of the present invention uses a semiconductor laser as an excitation light source.

A solid-state laser device according to a fourteenth aspect of the present invention is the solid-state laser device according to any one of the first to thirteenth aspects, further comprising a laser resonator that extracts light from a solid-state element.

In claim 1 of the present invention, a solid element including an active solid medium, a flow tube through which a cooling medium for cooling the solid element flows, arranged so as to surround the solid element, an inner surface formed of a diffuse reflection surface, and A light collector that directly or indirectly sandwiches and holds the flow tube, is disposed outside the light collector, an excitation light source that emits excitation light that excites the solid-state element, and provided in the light collector, Since the solid-state laser amplifying device is configured by the opening for guiding light, a solid-state laser amplifying device that stably generates a high-output, high-quality laser beam can be obtained at a low cost with a simple configuration.

Further, in claim 2 of the present invention, since both ends of the light collector are held by the side plates, a solid-state laser amplifying device that stably generates a high-output, high-quality laser beam is provided in the same manner as described above. It can be obtained at a low cost with a simple configuration.

According to the third aspect of the present invention, since the light collector is supported on a base different from the side plate supporting the flow tube, the light collector can be easily removed, and the light collector can be quickly replaced. It can be carried out.

According to a fourth aspect of the present invention, the optical element for transmitting incident light by total internal reflection allows the excitation light emitted from the excitation light source to reach the periphery of the opening of the condenser or the periphery of the solid state element by total internal reflection. Since it is configured to guide, the light of the excitation light source can be guided to the inside of the light collector with almost no loss, and the intensity distribution of the excitation light becomes uniform, and the light is diffused and reflected more uniformly in the light collector, The solid-state element can be excited very uniformly, and high-quality laser amplification can be performed with high efficiency.

According to a fifth aspect of the present invention, an optical element for transmitting incident light by total internal reflection is provided for the device of the first to third aspects, and the excitation light is supplied to the periphery of the opening of the condenser or to the solid-state element. Since the configuration is such that the light is guided to the periphery, in addition to the above-described effects, when the light collector is rotated around the flow tube to change the excitation position to the solid state element, the excitation light can be stably guided.

According to the sixth aspect of the present invention, the optical element that transmits light by total reflection by the optical thin film provided on the side surface allows the excitation light emitted from the excitation light source to be emitted around the opening of the condenser or around the solid-state element. Since the guiding is performed, the same effect as that of the fourth aspect is obtained. Further, since an inexpensive material can be used, there is an effect that the entire apparatus can be made inexpensive.

According to a seventh aspect of the present invention, the device of the first to third aspects is further provided with an optical element for transmitting light by total reflection by an optical thin film provided on a side surface, and the excitation light is transmitted through an aperture of a condenser. Since the structure is guided to the periphery of the unit or the periphery of the solid-state element, the same effect as that of the fifth aspect is obtained.

Further, in claim 8 of the present invention, an optical element having a refractive index distributed in a lens shape guides the excitation light emitted from the excitation light source to around the opening of the condenser or around the solid-state element. Therefore, there is an effect similar to that of the fourth aspect. In addition, stable quality excitation light can be guided into the inside of the condenser without being affected by the length of the optical element, and high-quality laser amplification can be performed.

According to a ninth aspect of the present invention, an optical element having a refractive index distributed like a lens is provided in the apparatus according to the first to third aspects, and the excitation light is supplied to the periphery of the opening of the condenser or to the solid state element. Since it is configured to guide to the periphery, the same effect as in claim 5 is obtained.

Further, in claim 10 of the present invention, since the optical element is disposed integrally with the excitation light source, the positional relationship between the light source and the solid element is kept constant even if the position of incidence of the excitation light on the solid element changes. Facilitates adjustment of the excitation distribution.

According to the eleventh aspect of the present invention, a plurality of openings are provided, and the positions of the plurality of openings are changed in at least one place when viewed from the axial direction of the solid-state element. And high quality laser amplification can be performed.

According to a twelfth aspect of the present invention, a plurality of openings are provided in the device according to the first to tenth aspects, and the positions of the plurality of openings are at least one position when viewed from the axial direction of the solid-state element. Because it is changed, uniform excitation distribution can be realized, high-quality laser amplification can be performed, and the position of excitation to the solid-state device is changed by rotating the condenser around the flow tube. At this time, the optimum position can be determined while observing the quality of the oscillating laser beam. In addition, when an optical element is used, the function of making the excitation light uniform works effectively, so that a more uniform amplification distribution can be obtained.

According to the thirteenth aspect of the present invention, since a semiconductor laser is used as the excitation light source, a high-efficiency and high-output excitation light can be generated from a compact excitation light source, and a high-efficiency and high-quality excitation light can be generated. Laser amplification can be performed.

Further, in claim 14 of the present invention, a laser resonator is used to extract a laser beam from a solid-state element excited by light from an excitation light source. Can be generated.

Embodiment 1 FIG.
FIG. 1 is a configuration diagram showing an embodiment of the present invention. FIG. 1A is a horizontal cross-sectional configuration diagram, FIG. 1B is a vertical cross-sectional configuration diagram, and FIG. FIG. 2 is a side view of the configuration viewed from a direction. In the figure, 1, 2, 3, 4, 5, 7, 40, 70 and 100 are exactly the same as the conventional device. Reference numeral 8 denotes a light collector arranged so as to surround the solid-state element 3 and an inner surface formed of a diffuse reflection surface. The light collector 8 is configured by arranging a plurality of light collectors in the axial direction of the solid-state element 3. Reference numeral 20 denotes a flow tube, and cooling water flows between the flow tube 20 and the solid element 3. Further, the condenser 8 is held by the flow tube 20 so as to sandwich the flow tube 20. Reference numeral 80 denotes an opening formed in a part of the side surface of the light collector, and 101 denotes a side plate supporting the flow tube 20.

In the solid-state laser device configured as described above, the solid-state element 3 including the active solid medium is disposed in a concentrator made of, for example, a ceramic having an inner surface formed of a diffuse reflection surface, and is introduced from the opening 80. It is excited by the excitation light 40 emitted from the semiconductor laser 4 and becomes a laser amplification medium for amplifying a laser beam. The spontaneous emission light generated from the laser amplification medium is amplified during the reciprocation between the resonators constituted by the mirror 1 and the mirror 2 to become a laser beam 7 having a uniform directivity. The light is emitted as a beam 70 to the outside.

In the above configuration, the light of the semiconductor laser not absorbed by the solid-state device 3 is diffused and reflected on the inner surface of the condenser after passing through the solid-state device, and again uniformly excites the solid-state device. The excitation efficiency in this case can be calculated in consideration of the probability of the number of light reflections on the diffuse reflection surface until the light is finally absorbed by the solid state device.

FIG. 2 shows the results of calculating the excitation efficiency of the solid-state device as a function of the reflectance of the inner surface of the light collector and the excitation efficiency (absorption rate) when the excitation light passes through the solid-state device only once. It can be seen that even if the wavelength of the excitation light, for example, a semiconductor laser changes and the absorptance of the solid state device changes from 20 to 100%, the change in the excitation efficiency of the solid state device is gradual. This indicates that an excitation light source having a wider range of wavelengths can be used as compared with the conventional example, and that there is no need to strictly control the wavelength. As a result, the yield in the manufacture of semiconductor lasers can be increased, and a simple and inexpensive device can be realized.

(4) The components absorbed by the solid state element 3 and not converted into laser light become heat, and the solid state element 3 heated by the heat is cooled by a cooling medium flowing in a flow tube arranged around the solid state element.

FIG. 3 shows an example of the results obtained by experiment on the oscillation characteristics of the solid-state laser device according to the first embodiment. Lasers generated from respective semiconductor lasers 4 using six continuous oscillation semiconductor lasers mainly composed of GaAlAs that generate spatially flat excitation light having a length of 1 cm and a width of 5 μm and having a wavelength of around 810 nm. Light is guided into the concentrator 8 through apertures 80 each having a length of 1.5 cm and a width of 0.5 mm provided on the side of the concentrator 8 prepared for each semiconductor laser 4. A thin Nd: YAG (Nd: Yttrium Aluminum Garnet) rod 3 having a diameter of 4 mm and a length of 100 mm housed in a light collector is excited to have a partially reflecting mirror 2 having a transmittance of 6% and a reflectance of 100%. Laser output was obtained by a stable resonator including the reflection mirror 1.

(4) When the output of all the semiconductor lasers was 72 W in total, a laser output of 25 W was obtained as the laser beam 70. The slope efficiency of the oscillation characteristic, so-called light-light slope efficiency, was 48%. This is the world record at the time of writing the description of the present invention. The use of a thinner rod facilitates the generation of a laser beam with good beam quality. Therefore, the achievement of such high recording with such a thin rod indicates that the configuration of the present invention can generate a high-quality laser beam with high efficiency.

In the above embodiment, a configuration in which a plurality of semiconductor lasers 4 are symmetrically arranged on the side surface of the solid-state device 3 has been described. However, the present invention is not limited to this, and one semiconductor laser 4 may be provided.

Further, in the above-described embodiment, the light collector 8 arranges a plurality of light collectors in the axial direction of the solid-state element 3 so that replacement of light collectors and adjustment of a beam incident position of each semiconductor laser are easy. Although the configuration in which each concentrator has the opening 80 is shown, one concentrator may have a plurality of openings.

In the above-described embodiment, the concentrator 8 is configured to be divided in the lateral direction along the axial direction of the solid state element 3 at the opening 80 and to hold the flow tube 20 from above and below. It is not necessary to limit the flow tube 20 to the vertical direction as shown in FIG.
With this configuration, a part of the split light collector can be removed, and the pattern of the light emitted from the opening can be seen. For example, the light of the semiconductor laser is incident on the opening. Can be confirmed.

Further, in the configuration of the present embodiment, it is also possible to rotate the light collector 8 around the flow tube, and to change the position of the opening to change the incident position of the excitation light. If this is the case, the solid-state element can be more uniformly excited, and high-quality laser amplification can be performed.

As described above, in the solid-state laser device having the above-described configuration, the solid-state device is arranged in the light collector in which the inner surface is formed by the diffuse reflection surface, and the solid-state device is excited by introducing the excitation light from the opening. In addition, the solid state device can be efficiently and uniformly excited.
In addition, since the excitation light is converted into a diffuse reflection beam irrespective of the divergence angle and beam quality of the excitation light, the solid state element can be excited, so that the divergence state of the incident beam, the beam mode, The solid-state element can be excited with almost no influence on the position of incidence on the opening, and therefore can stably oscillate even with mechanical vibration, and can be replaced without further fine-tuning. Can be.
Further, since the condenser is supported by sandwiching the flow tube around the solid element, the relationship between the condenser and the solid element is stabilized, and stable operation can be realized. In addition, the center of the flow tube, that is, the center of the solid-state element, and the center of the light collector can be made to coincide with each other, and excitation can be performed more uniformly.

Embodiment 2 FIG.
5A and 5B are configuration diagrams showing a solid-state laser device according to Embodiment 2 of the present invention. FIG. 5A is a cross-sectional configuration diagram, FIG. 5B is a vertical cross-sectional configuration diagram, and FIG. It is the side view block diagram which looked at the optical device from the lateral direction. In the first embodiment, the configuration in which the condenser 8 is held around the solid element with the flow tube 20 interposed therebetween has been described. However, both ends of the condenser are mechanically screwed to a side plate supporting the flow tube 20 or the like. Alternatively, as shown in FIG. 5, a screw 102 for connecting the two side plates 101 is provided, and the distance between the two side plates 101 is made variable with the screw 102. Alternatively, the distance between the side plates may be reduced to hold the light collector 8 in pressure contact.

に す る By doing so, the relationship between the light collector and the solid state element is stabilized, and stable operation can be realized. In addition, the center of the flow tube, that is, the center of the solid-state element, and the center of the light collector can be made to coincide with each other, so that excitation can be performed more uniformly.

Furthermore, also in the configuration of the present embodiment, it is possible to rotate the light collector 8 around the flow tube, and to change the position of the opening to change the incident position of the excitation light. If this is the case, the solid-state element can be more uniformly excited, and high-quality laser amplification can be performed.

Embodiment 3 FIG.
6A and 6B are configuration diagrams showing a solid-state laser device according to Embodiment 3 of the present invention. FIG. 6A is a cross-sectional configuration diagram, FIG. 6B is a vertical cross-sectional configuration diagram, and FIG. It is the side view block diagram which looked at the optical device from the lateral direction. As a method of holding the light collector 8, the light collector 8 may be fixed on the base 100 as shown in FIG. In this case, the light collector 8 can be separated from the side plate 101, but it is necessary to adjust the height of the solid element 3 from the base 100. For example, the height of the solid element 3 It is sufficient to provide an adjusting device for adjusting the center so that the center coincides with the center of the flow tube 20, that is, the center of the solid state element 3, or to design the structure so that the center can be fitted with mechanical precision.

As described above, since the light collector 8 is supported by the base 100 different from the side plate 101 that supports the flow tube 20, the light collector 8 can be easily removed, and when the dirt is generated inside the light collector. In addition, the light collector can be quickly replaced.

Embodiment 4 FIG.
7 is a cross-sectional configuration diagram showing a main part of a solid-state laser device according to Embodiment 4 of the present invention. FIG. 7 (a) is a horizontal cross-sectional configuration diagram, and FIG. 7 (b) is a vertical cross-sectional configuration diagram. In the figure, reference numeral 45 denotes a plate-like optical waveguide optical element made of, for example, sapphire or undoped YAG, which guides the excitation light 40, and is disposed in the opening 80.

In the solid-state laser device configured as described above, as in the first to third embodiments, the solid-state element 3 including the active solid medium is provided inside a concentrator made of, for example, a ceramic having an inner surface formed of a diffuse reflection surface. The laser amplifying medium, which is arranged and excited by the excitation light 40 emitted from the semiconductor laser 4 and introduced from the opening 80, becomes a laser amplification medium for amplifying a laser beam. The spontaneous emission light generated from the laser amplification medium is amplified during the reciprocation between the resonators constituted by the mirror 1 and the mirror 2 to become a laser beam 7 having a uniform directivity. The light is emitted as a beam 70 to the outside.

動作 The operation of the optical waveguide optical element 45 characteristic of this embodiment will be added. The end face of the optical waveguide optical element 45 is coated with an anti-reflection coating for the excitation light, and the light of the excitation light source 4 is guided into the optical waveguide optical element 45 with almost no loss. The optical waveguide optical element 45 is made of sapphire or YAG (Yttrium @ Aluminum @ Garnet), and has a large refractive index of about 1.7 to 1.8. The light is totally reflected by the upper and lower surfaces of the optical waveguide optical element 45 and guided to the inside of the condenser with almost no loss. In fact, experiments have demonstrated transmission characteristics of 99% or more.

(4) The optical waveguide optical element 45 also has the function of making the spatial distribution of the excitation light uniform. For example, of the light generated from the excitation light source 5 composed of a semiconductor laser, the light in the central portion passes through the optical waveguide optical element 45 without being totally reflected, but the peripheral portion is folded back to the central portion by total reflection. The light is guided from the optical waveguide optical element 45 into the light collector. In this manner, the central portion and the peripheral portion can be mixed to make the excitation light intensity distribution constant. When the intensity distribution of the excitation light is made uniform and guided into the light collector in this way, the effect of uniformizing the excitation of the solid-state device by the diffuse reflection of the light collector can be enhanced.

As the optical waveguide optical element 45, an optical element that transmits light by total reflection by an optical thin film provided on a side surface, for example, an element in which a thin film of, for example, gold, aluminum, or Hooker magnesium is deposited on glass or fused silica is used. 7 may be configured similarly to FIG. In this case, since an inexpensive material can be used, there is also an effect that the entire device can be made inexpensive.

Further, the optical waveguide element 45 may be configured as shown in FIG. 8 by using an optical element that transmits light by a lens action by changing the internal refractive index smoothly, for example, an optical fiber. In this case, since the excitation light can be guided while maintaining the beam quality of the excitation light source, the excitation light having a stable quality is guided into the inside of the condenser without being affected by the length of the optical element for guiding the excitation light. As a result, the excitation distribution inside the solid-state device can be stabilized, and high-quality laser amplification can be performed.
When a semiconductor laser is used as the excitation light source, the divergence of the excitation light is large only in the vertical direction. Therefore, the refractive index may be made smooth only in the vertical direction.

When the optical waveguide optical element 45 is used as described above, since the opening of the condenser can be closed by the optical waveguide optical element 45, the flow tube 20 is removed and the inside of the condenser is cooled. The agent can be flowed to act as a flow tube inside the collector.

Further, the optical waveguide optical element 45 may be integrally disposed in the same package as the light source 4. In this case, the optical element 45 is placed on the side surface of the rod while maintaining the position adjustment state of the light source 4 and the optical element 45. Can be easily changed. For example, in contrast to the configuration of the first or second embodiment, the light collector 8 is configured to be rotatable, and the position of the opening 80 is changed to change the position of the excitation light incident on the solid-state element. At this time, if the pumping light is guided using the optical waveguide optical element 45 integrated with the light source 4, the transmission efficiency of the pumping light does not change even if the position is shifted or the incident angle is changed, and the pumping light is stably transmitted. Can lead.

Embodiment 5 FIG.
9A and 9B are configuration diagrams showing a solid-state laser device according to Embodiment 5 of the present invention. FIG. 9A is a cross-sectional configuration diagram, FIG. 9B is a vertical cross-sectional configuration diagram, and FIG. It is the side view block diagram which looked at the optical device from the lateral direction. In the present embodiment, as shown in FIG. 9, the position of the opening 80 provided in the light collector 8 changes in the height direction, and therefore, the installation position of the excitation light source 4 also changes in the height direction. Is changing.

In the solid-state laser device of the present embodiment, similarly to the above-described first to third embodiments, the solid-state element 3 including the active solid medium is arranged in a concentrator made of, for example, a ceramic having an inner surface formed of a diffuse reflection surface. The laser beam is excited by the pumping light 40 emitted from the semiconductor laser 4 introduced from the opening 80 and becomes a laser amplification medium for amplifying the laser beam. The spontaneous emission light generated from the laser amplification medium is amplified during the reciprocation between the resonators constituted by the mirror 1 and the mirror 2 to become a laser beam 7 having a uniform directivity. The light is emitted as a beam 70 to the outside.

(4) The arrangement of the opening 40 characteristic of the present embodiment will be additionally described. In the present embodiment, three sets of two opposing semiconductor lasers 4 are arranged in the axial direction of the solid-state device, that is, a total of six, and the incident position of the excitation light to the solid-state device is set from the axial direction of the solid-state device. I try to be as close as possible, so as not to concentrate on a particular place. Since the amplification factor of the solid-state element is represented by an integral value of the solid-state element in the axial direction, if the incidence of the excitation light viewed from the axial direction is equalized in this way, the amplification rate in the cross-section of the solid-state element is also equal, Generation and amplification of a high-quality laser beam are facilitated.

FIG. 9 shows a configuration in which two semiconductor lasers are arranged in each stage in order to make the incident position on the solid-state device uniform, but it is needless to say that the configuration is not limited to this. If a plurality of openings provided in the solid-state element are provided and the position of the solid-state element viewed from the axial direction is also changed in at least one of the openings, the uniformity of the amplification distribution in the cross-section of the solid-state element is obtained. It is greatly improved.
When the incident power from the pump light source is increased, a more uniform arrangement of the incident position is required for generating and amplifying a high-quality beam, so that the above configuration is particularly effective.

に お い て Also in the present embodiment, a configuration using the optical waveguide optical element 45 used in the fourth embodiment can be considered. As described above, the action of making the excitation light uniform by the optical waveguide optical element 45 effectively acts, and a more uniform amplification distribution can be obtained.

Embodiment 6 FIG.
In the fifth embodiment, the position of the opening 80 provided in the light collector 8 is changed. However, in contrast to the structure in which the light collector 8 is fixed with the flow tube 20 interposed therebetween as shown in the first embodiment, The concentrator 8 may be rotated around the tube 20 so as to be excited uniformly from the surroundings in the cross section when viewed from the axial direction of the solid-state device 3. FIG. 10 shows an example of such a configuration. FIG. 10A is a cross-sectional configuration diagram, and FIG. FIG. 3 is a diagram showing the appearance as viewed from the axial direction of the solid state element. In this case, since the plurality of light collectors 8 divided in the axial direction can freely rotate, the optimum position can be determined while observing the quality of the oscillating laser beam.

The above embodiment is an example of application to the configuration of the first embodiment. However, the configuration described in the second embodiment in which the light collector 8 is sandwiched between the side plates 101 and fixed is also applied. The concentrator 8 may be rotated around the flow tube 20 so as to be excited uniformly from the periphery in the cross section when viewed from the axial direction of the solid-state element 3. Also in this case, since the plurality of light collectors 8 divided in the axial direction can freely rotate, the optimum position can be determined while observing the quality of the oscillating laser beam.

Embodiment 7 FIG.
In any of the above embodiments, an example has been described in which a semiconductor laser is used as an excitation light source, and light is directly guided to an opening of a condenser or an optical waveguide optical element, but is not limited thereto. Another excitation source such as an ion laser may be used. For example, as shown in FIG. 11, a configuration in which light of a pulsed semiconductor laser emitting in a planar shape is guided to an opening 80 by using a condenser lens 6. Is also conceivable. The point is that the light may be guided to the opening 80 provided in the condenser 8.

Embodiment 8 FIG.
In each of the above embodiments, the solid-state element excited by the excitation light source is used as an amplification medium, and a laser beam is extracted from the amplification medium by a laser resonator. It can also be used as a device. FIG. 12 shows an example of a configuration in which the laser beam 70 extracted from the solid-state laser device 200 by the laser resonators 1 and 2 is amplified by the solid-state laser amplification device 300 and extracted outside as the laser beam 71.

In each of the above embodiments, the solid element and the flow tube have been described as having a circular cross section. However, each of the solid elements and the flow tube is not limited to a circular shape, and may be a rectangle or an ellipse.

Although not particularly described in any of the above-described embodiments, a portion of the laser beam, such as the side surface of the flow tube or an optical element, through which a laser beam does not pass, which is not particularly indicated, has nothing like an ordinary optical element. By providing a reflective thin film, the passage loss is reduced, and efficient laser oscillation can be realized.

Although an example using Nd: YAG as the solid state element has been described, the present invention is not limited to this, and any solid state element capable of photoexcitation may be used.

FIG. 1 is a configuration diagram illustrating a solid-state laser device according to a first embodiment of the present invention. FIG. 3 is an explanatory diagram illustrating an operation of the solid-state laser device according to the first embodiment of the present invention. FIG. 3 is an explanatory diagram illustrating an operation of the solid-state laser device according to the first embodiment of the present invention. FIG. 4 is a configuration diagram showing another solid-state laser device according to the first embodiment of the present invention. FIG. 6 is a configuration diagram illustrating a solid-state laser device according to a second embodiment of the present invention. FIG. 9 is a configuration diagram illustrating a solid-state laser device according to a third embodiment of the present invention. FIG. 9 is a configuration diagram illustrating a solid-state laser device according to a fourth embodiment of the present invention. FIG. 13 is a configuration diagram illustrating another solid-state laser device according to Embodiment 4 of the present invention. FIG. 13 is a configuration diagram showing a solid-state laser device according to a fifth embodiment of the present invention. FIG. 13 is a configuration diagram illustrating a solid-state laser device according to a sixth embodiment of the present invention. FIG. 14 is a configuration diagram illustrating a solid-state laser device according to a seventh embodiment of the present invention. FIG. 16 is a configuration diagram illustrating a solid-state laser device according to an eighth embodiment of the present invention. FIG. 9 is a configuration diagram illustrating a conventional solid-state laser device. FIG. 9 is an explanatory diagram illustrating an operation of a conventional solid-state laser device.

Explanation of reference numerals

1 reflection mirror, 2 partial reflection mirror, 3 solid state device, 4 excitation light source, 5 power source, 7 laser beam, 8 concentrator, 20 flow tube, 40 excitation light, 45 optical waveguide optical element, 70 laser beam, 71 laser beam , 80 opening, 100 base, 101 side plate, 102 screw, 200 solid laser device, 300 、 solid laser amplifier.

Claims (14)

A solid element containing an active solid medium, a flow tube through which a cooling medium for cooling the solid element flows, disposed so as to surround the solid element, an inner surface formed of a diffuse reflection surface, and directly or indirectly connecting the flow tube. A light collector that is disposed outside the light collector and emits excitation light that excites the solid-state element, and an opening that is provided in the light collector and guides the excitation light. Solid-state laser amplifier. A solid element containing an active solid medium, a flow tube through which a cooling medium for cooling the solid element flows, a light collector arranged so as to surround the solid element, and an inner surface formed of a diffuse reflection surface, both ends of the light collector A side plate holding the unit, an excitation light source that is disposed outside the condenser and emits excitation light that excites the solid-state element, and a solid-state laser that is provided in the condenser and has an opening that guides the excitation light Amplifying device. A solid element containing an active solid medium, a flow tube through which a cooling medium for cooling the solid element flows, a light collector arranged so as to surround the solid element, and an inner surface formed of a diffuse reflection surface, holding the light collector A solid-state laser amplifying device that is provided outside the condenser and that emits excitation light that excites the solid-state element, and that is provided in the condenser and has an opening that guides the excitation light. . A solid-state element including an active solid medium, a concentrator arranged so as to surround the solid-state element, an inner surface formed of a diffuse reflection surface, an excitation arranged outside the concentrator and emitting excitation light for exciting the solid-state element A solid-state laser provided with a light source, an opening provided in the condenser, for guiding the excitation light, and an optical element for transferring the light emitted from the excitation light source to the periphery of the opening or the solid-state element by total internal reflection Amplifying device. 4. The solid-state laser amplifying device according to claim 1, further comprising an optical element for transferring light emitted from the excitation light source to the periphery of the opening or the periphery of the solid-state element by total internal reflection. Amplifying device. A solid-state device including an active solid medium, a concentrator arranged so as to surround the solid-state device, an inner surface formed of a diffuse reflection surface, and an excitation device that is disposed outside the concentrator and emits excitation light that excites the solid-state device A light source, an opening provided in the light collector, for guiding the excitation light, and an optical thin film on which light emitted from the excitation light source is totally reflected are provided on side surfaces, and the emission light is provided around the opening or on a solid surface. A solid-state laser amplifying device equipped with an optical element that transfers light to the periphery of the element. 4. The solid-state laser amplifying device according to claim 1, wherein an optical thin film on which light emitted from the excitation light source is totally reflected is provided on a side surface, and the emitted light is transferred to the periphery of the opening or the periphery of the solid-state device. A solid-state laser amplification device comprising an optical element. A solid-state device including an active solid medium, a concentrator arranged so as to surround the solid-state device, an inner surface formed of a diffuse reflection surface, and an excitation device that is disposed outside the concentrator and emits excitation light that excites the solid-state device A light source, an opening provided in the light collector, for guiding the excitation light, and an optical element having a refractive index distributed in a lens shape and transmitting light emitted from the excitation light source to the vicinity of the opening or the solid state element; Solid-state laser amplifying device equipped with elements. 4. The solid-state laser amplifying device according to claim 1, further comprising an optical element having a refractive index distributed in a lens shape and transmitting the light emitted from the excitation light source to the periphery of the opening or the periphery of the solid-state device. A solid-state laser amplifying device characterized by the above-mentioned. 10. A solid-state laser amplifying device, wherein the optical element according to claim 4 is integrated with an excitation light source. A solid-state device including an active solid medium, a concentrator arranged so as to surround the solid-state device, an inner surface formed of a diffuse reflection surface, and an excitation device that is disposed outside the concentrator and emits excitation light that excites the solid-state device The light source includes a plurality of openings provided in the light collector and guiding the excitation light, and each of the positions of the plurality of openings changes in at least one place when viewed from the axial direction of the solid state element. A solid-state laser amplifier. 11. The solid-state laser amplifying device according to claim 1, wherein a plurality of openings are provided, and positions of the plurality of openings are changed at least at one position when viewed from an axial direction of the solid-state element. A solid-state laser amplifier. 13. The solid-state laser amplifier according to claim 1, wherein the pumping light source is a semiconductor laser. A solid-state laser device comprising: the solid-state laser amplification device according to claim 1; and a laser resonator that extracts light from a solid-state element.

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