JP4867032B2 - Solar pumped laser equipment - Google Patents

Description

The present invention relates to a solar light pumped laser device.

There are Xe and Kr flash lamps and semiconductor lasers as optical excitation sources such as solid state laser and liquid laser. Excitation using Xe or Kr flash lamps employs a method in which a lamp is placed at one of the two focal points of the elliptical mirror and a laser rod is placed at the other. In semiconductor excitation, a semiconductor laser is placed in the vicinity of a solid laser head or rod without an optical system. In particular, a high power laser often causes cooling water to flow between the light source and the laser medium.

As shown in Non-Patent Document 1, the CGYoung of the United States of America collected sunlight with a parabolic mirror and irradiates the laser rod. Successful. In 1998, at the Weitzmann Institute in Israel, as shown in Non-Patent Document 2, sunlight was irradiated to an Nd, Ho-doped alexandrite laser and succeeded in kW-class laser oscillation with a conversion efficiency of 30%. In 2001, Research Institute of Laser Technology focused sunlight with a Fresnel lens as shown in Non-Patent Document 3, puts the light into the cladding part of the fiber laser, and used the laser medium in the core part as the cladding. A laser excitation method using reflected light is proposed. In 2002, NASA's Jet Propulsion Laboratory proposed a method of bundling optical fiber lasers as shown in Non-Patent Document 4. In this way, if a parabolic mirror or Fresnel lens is used to concentrate sunlight from 1,000 to 10,000 times and efficiently absorb it in a three-level or four-level laser medium, a sufficient inversion distribution will result in oscillation. Can be obtained. However, the beam quality and medium damage due to the thermal effect when sunlight is directly incident can be considered. In September 2005, Yabe Takashi put a laser head in the cooling water to cool the laser medium. It proposes the use of hot water for wastewater. As shown in Patent Document 1, the present inventor circulates sunlight condensed by a toroidal mirror or a toroidal lens in a toroidal glass container with cooling water, and excites high density parallel light through the water in the laser medium therein. Is disclosed. Therefore, the next remaining issue is the development of a method for efficiently absorbing sunlight into the laser medium. As an application of lasers obtained from sunlight, Patent Document 2 describes an energy supply network using sunlight-excited lasers, which reflects laser light oscillated in outer space with an artificial satellite and creates an airship floating in the stratosphere. It is disclosed to irradiate, where it is microwave converted and sent to the terrestrial power grid.

When it has a broad spectrum like sunlight, the calorific value becomes large, so a large-scale cooling device is required. On the other hand, since the oscillation wavelength of the semiconductor laser is close to the absorption band of the fiber laser medium, high-efficiency laser oscillation can be expected. According to Non-Patent Document 6, a double clad fiber laser doped with Yb absorbs at 975 nm, so that it is optically pumped with a 2.2 W high-power semiconductor laser diode into a 20-meter fiber at 100 μφ, that is, 1.3 W output, ie 63% High efficiency is achieved. However, in order to oscillate efficiently using sunlight with a broad spectrum of 350 to 1500 nm on the ground, it is necessary to cool and remove most of the sunlight that is not used for excitation, or to use a bandpass filter, diffraction grating, or prism. In addition to selective excitation using only the excitation wavelength, there is an urgent need to search for a doping agent having absorption in these wavelength regions.
Japanese Patent Application No. 2005-338425 Japanese Patent Application No. 2001-330673 (Japanese Patent Laid-Open No. 2003-134700) Japanese Patent Application No. 2006-41870 Japanese Patent Application No. 2003-298158 (Japanese Patent Laid-Open No. 2005-070245) CCYoung; Applied Optics, 5, p993 (1966) Israel '; IEEE Spectrum, May, p30 (1998) Kazuo Imasaki; Laser Cross, No. 158, p2 (2001) D. Maynard; "Power Beaming Technology Vision &Goal", Proceeding of Space Solar Power Concept And Technology Maturation Program Technical Interchenge Meeting (2002) Takashi Yabe; Tokyo Tech Chronicle No. 402, p4 (2005. Sep.) Hideaki Ito et al .; Mitsubishi Electric Industrial Time Report No. 101, p. 21-24 (2004) Laser Handbook, Editor Laser Society of Japan, Publisher Ohm Co., Ltd. Published December 15, 1982 Masataka Murahara, “Room-temperature adhesion and coating of quartz glass using excimer lamps”, Ceramics, 41 [6], 440-443 (2006) M.Murahara, N.Sato, and A.Ikadai, Optics Letters, 30 [24]

When sunlight is condensed 1000 to 10,000 times and efficiently absorbed by a three-level or four-level laser medium, a sufficient inversion distribution leading to oscillation can be obtained. In particular, the fiber laser can confine or absorb the excitation light, has a large volume capacity of the core part, and has a large surface area because of its length relative to the diameter of the cross section, and has a high cooling efficiency. For this reason, the fiber laser employs a method in which semiconductor laser light is condensed and light is introduced along the optical axis of the fiber. The inventor of the present application discloses a method in which a quartz glass container having a spherical surface, a cylinder, or a toroidal surface is filled with cooling water and a fiber laser medium is arranged on the outer wall thereof. However, it is difficult to dissipate heat with a cylindrical laser medium with a large core diameter, and unless the large amount of cooling water is cooled with a high-speed flow, thermal destruction of the laser medium is inevitable. In particular, since sunlight has a wide spectrum, it generates a large amount of heat, and it is difficult to directly enter high-density sunlight into a solid laser medium. Due to this thermal action, continuous oscillation is impossible.

Therefore, in the present invention, water or silicone is used as a coolant with high-density light such as sunlight, semiconductor laser light, xenon lamp or mercury lamp light after spectroscopy from the incident window of the integrating sphere glass container whose outer wall is coated with a reflection film. It is intended to be injected into the laser medium through oil.

As a result of earnest research to achieve the above object, the inventor of the present application has found that the outer wall of an integrating sphere, cylinder, or truncated cone glass container filled or circulated with cooling water or silicone oil is made of gold, aluminum, silver or the like. Since the metal vapor deposition film and the dielectric multilayer film are coated, the laser medium fixed inside the glass container can be excited by high-density sunlight incident from the incident window of the glass container directly through the cooling water. Thus, since only the excitation wavelength of the laser medium is incident on the glass container, thermal denaturation and thermal destruction of the laser medium can be avoided, and continuous oscillation is also possible. On the other hand, the thermal conductivity of silicone oil is about 1/4 of water and the specific heat is about 1/3 of water, but the water freezes at 0 ° C, while silicone oil is fluid at -65 ° C. Indicates. Furthermore, water boils at 100 ° C, but silicone oil does not change to 200 ° C. In addition, when the wavelength of water becomes longer than 650 nanometers, the transmittance is extremely lowered. However, silicone oil is transparent even at 2000 nanometers. As for ultraviolet light transmission, both transmittances decrease as the wavelength becomes shorter, but both transmit up to 190 nanometers. Considering the above properties from the laser medium side, it can be seen that silicone oil has characteristics that cannot be considered with water. That is, if the laser medium receives high-density sunlight or becomes laser-oscillated and becomes a high temperature, the cooling water evaporates and the periphery of the laser medium becomes full of bubbles. However, although silicone oil has a low viscosity, it has fluidity up to 200 ° C. and above, and no gas is generated. Moreover, since silicone oil has a defoaming action, no foam is produced. Water as a refrigerant is at most 0 ° C. even when cooled. However, silicone oil can be cooled to -65 ° C, and the cooling efficiency of the laser medium is high. In addition, although light excitation such as a neodymium-doped yag laser or fiber laser uses a wavelength of 800 nanometers or more, it is inefficient to perform excitation in cooling water. However, efficient excitation is possible in silicone oil. Deliquescent non-linear optical crystals such as KDP, CLBO and BBO emit double waves in the ultraviolet region, but cannot be cooled with water. However, in silicone oil, both excitation laser light and harmonics can be emitted.

The high-density sunlight condensed by the objective lens and the mirror is incident from one incident window on both end faces of an axisymmetric circular glass container such as an integrating sphere filled with cooling water or silicone oil, a cylinder or a truncated cone. The high-density light is incident from an incident window of a glass container located before or behind the focus of sunlight. The light then travels into the glass container and is reflected many times by the reflective film coated on the outer wall of the glass container to excite the entire laser medium. As described above, the present invention is characterized in that light incident on a rotationally axisymmetric quadratic curved glass container such as an integrating sphere, a cylinder, or a truncated cone is confined inside and used for excitation of the laser medium. From this point of view, an integrating sphere type glass container is most suitable as an excitation shape.

As disclosed in Non-Patent Document 7, trivalent neodymium (Nd ³⁺ ), the most popular solid-state laser medium, is a four-level laser that performs an efficient laser transition from 720 to 830 nanometers. The laser emits 1060 nanometer pulses and continuous oscillation with 808 nanometer excitation. On the other hand, trivalent chromium (Cr ³⁺ ) represented by a three-level laser has a peak wavelength of 406 and 550 nanometers in the ruby laser. It is done. The 514.5 nanometer Ar + laser can continuously oscillate. However, when these solid-state laser media are excited with high-density light, the laser element itself becomes high temperature due to excitation light or laser output, and laser oscillation when cooling is insufficient causes a thermal lens effect or the like inside the laser medium, leading to destruction of the medium. Forced cooling is essential to prevent this. Furthermore, in order to optically excite the laser medium, the refrigerant needs to transmit the excitation light. The best refrigerant that satisfies both is water. However, the spectral width of sunlight is too wide compared to semiconductor lasers.

The sunlight on the ground contains light having a wavelength of 300 to 1900 nanometers, and the excitation wavelength of a solid laser medium including a fiber laser is light in an extremely narrow wavelength band between 400 and 1000 nanometers. In this way, sunlight-excited lasers use less than 1% of the energy of sunlight, and the rest are used to heat and thermally destroy the laser medium. Cooling is performed to reduce this drop. Of course, in the future, it will be possible to select a laser medium to make it shorter, but this is not an effective use of energy. The collected sunlight is passed through a bandpass filter, a bandpass filter that combines a short wavelength cut filter and a long wavelength cut filter, a cold mirror, a cold filter, etc. The excitation waveband spectrum of each laser medium is separated by one or a plurality of slits or reflecting mirrors and then condensed and irradiated for each excitation laser medium to be used for excitation of each solid-state laser oscillation. As a result, light other than laser medium excitation can be eliminated, and efficient laser oscillation can be achieved. Of course, continuous oscillation is also possible. The remaining spectrum is condensed by one to a plurality of spherical mirrors and used for metallurgy, melting or metal oxide reduction. It is also used as a heat source for hot water and steam power generation. Furthermore, light of 300 to 400 nanometers is used as a solar cell excitation light source or a photochemical reaction light source. In order to split sunlight, the light is condensed by a spectroscopic prism, bandpass filter or diffraction grating at the time of parallel light before entering the objective mirror or objective lens, and only the necessary wavelength is collected, or the objective mirror or objective lens or A band-pass filter is deposited on the incident window of the housing for exciting the laser medium to transmit or reflect only a specific wavelength, or create a Fresnel lens with a lens effect and a spectral effect on the objective lens, and light of a specific wavelength. It is also possible to selectively focus only.

The relationship between sunlight and cooling water is also complex. The spectral distribution of sunlight falling on the earth's surface is 300 to 2000 nanometers, but its intensity is highest at 450 to 500 nanometers and extremely small below 700 nanometers. On the other hand, the absorption of water is 200 to 800 nanometers, and the absorption in the near infrared region beyond that is very large. That is, all light having a wavelength longer than 800 nanometers is absorbed by water and converted into hot water. If converted to hot water, high-speed flow cooling may be performed, but the most important thing to note is that the excitation wavelength of a neodymium-doped yag laser that is attracting attention as a solar-excited laser medium that can obtain high output is 808 nanometers, This is the last line that excites the laser medium by passing light of this wavelength through water. That is, the laser medium placed on the rotation axis at the center of the container can be excited while repeating reflection several times by the reflection film coated on the outer wall of the glass container of the present invention, but the efficiency is low. The most recommended laser pump in the water is 450 to 530 nanometers, which share the wavelength range where the strongest energy can be obtained in the sunlight spectrum on the surface and the wavelength range where water absorption is the weakest. A laser or a chrome-doped yag laser is desirable. However, when sticking to the neodymium-doped yag laser that provides the highest output, instead of water, a silicone oil that is transparent from the ultraviolet ray 300 to the near infrared ray of 2000 nanometers and has a water-like viscosity and a relatively high thermal conductivity is used. Used as secondary coolant. However, when a laser medium is immersed in silicone oil, it is not necessary to form a reflection film, an antireflection film or a protective film on the surface of the laser medium.

Since the outer wall of the glass container is coated with a reflective film that reflects sunlight, it is difficult to think of film peeling by cooling water or thermal destruction of a high-power laser. However, the laser medium and the reflective film deposited on its end face are also exposed to high-speed cooling water. Therefore, it is necessary to attach a protective film to the reflection film as the antireflection film or laser resonator on the side surface of these laser media. However, there are few hard films that show laser resistance in water. As shown in Patent Documents 4 and 5 and Non-Patent Documents 8 and 9, the inventor of this application applies silicone oil to the surface of an optical sample in an oxygen gas atmosphere, and irradiates it with Xe2 excimer lamp light to make it water resistant. It is disclosed that a high hardness protective film having a Mohs hardness of 5 can be obtained.

A quartz glass prism having a structure in which the exit surface is a cylindrical surface and the cylinder axis is parallel to the main cross section of the prism in order to make the spectrum emitted from the spectroscopic prism have high density energy at the irradiation part of the excitation medium or object Can effectively obtain the energy of the target wavelength band.

According to the present invention, a high-efficiency laser device is obtained by introducing spectrally-divided sunlight incident on an incident window of an integrating sphere glass container whose outer wall is coated with a reflective film into a laser medium via cooling water or silicone oil. Can be provided.

The condensed sunlight is converted into parallel light and then demultiplexed by a spectroscopic prism. The selected spectrum is used as an excitation light source for the laser medium. It can be provided as a heat source for water or steam power generation, a solar cell excitation light source or a photochemical reaction light source.

Utilizing the vitrification of silicone oil by photo-oxidation, the laser medium surface coating, the formation of a water-resistant protective film on the end face of the laser medium, and the optical adhesion of flat quartz glass suppress the attenuation of laser output and have laser resistance. A high-output and high-efficiency optically pumped laser device can be provided.

Hereinafter, embodiments of the present invention will be described with reference to FIGS.

The operation principle of the solar light excitation laser device of the present invention will be described with reference to FIG. A wavelength selective film 3 such as a cold filter or a cold mirror is deposited on the incident windows 2 on both end faces of the rotationally symmetric quadric curved glass container 1 such as an integrating sphere, cylinder or truncated cone, and only the excitation light 4 is incident thereon. Light other than is removed by reflection. Here, when the incident light 5 is split into the excitation light of the laser medium, the wavelength selection film 3 is not evaporated and remains the incident window 2. A cylindrical laser medium 7 placed with the symmetry axis 6 as the optical axis is fixed to the other end of the glass container 1 with an attachment jig 8, and the outer wall 9 of the glass container 1 has an incident high density to excite the laser medium 7. In order to reflect light, a metal film 10 such as gold, aluminum, or silver or a dielectric multilayer film 10 is deposited. Then, water 12 or silicone oil 13 is circulated through the liquid inlet / outlet valve 14 as a coolant in the glass container 11, and the high-density sunlight 15 collected by the objective mirror or lens from the incident window 2 of the glass container 1 is separated. The concentrated high-density sunlight 15 is incident from the incident window 2 of the glass container 1 after or before condensing. Here, when the cylindrical laser medium 7 is used in the cooling water 12, the reflective film portion 16 on the high-density light incident window side and the laser medium side face 17 are coated with silicone oil and then photooxidized with vacuum ultraviolet light to be water resistant. The membrane 18 is coated. On the other hand, when silicone oil 13 is used as a coolant, there is no need for oxide film coating.

FIG. 2 is a schematic view in which high-density light is incident on an integrating sphere type optically pumped laser device. A wavelength selective film 3 such as a cold filter or a cold mirror is deposited on the incident windows 2 on both end faces of the integrating sphere type glass container 24 (rotation-axisymmetric quadratic curved glass container 1), and only the excitation light 4 is incident. The light is reflected and removed. A cylindrical laser medium 7 placed with the symmetry axis 6 as the optical axis is fixed to the other end of the glass container 1 with an attachment jig 8, and the outer wall 9 of the glass container 1 has an incident high density to excite the laser medium 7. In order to reflect light, a metal film 10 such as gold, aluminum, or silver or a dielectric multilayer film 10 is deposited. Then, water 12 or silicone oil 13 is circulated inside the glass container 11 as a coolant, and after collecting high-density sunlight 15 collected by an objective mirror or lens from the incident window 2 of the glass container 1 (focal point 21). Or it is made to inject from the entrance window 2 of the glass container 1 before condensing. The incident light 4 reflected many times by the reflective film 10 deposited on the outer wall 9 of the integrating sphere glass container 24 excites the laser medium 7 and the laser light 20 is output.

FIG. 3 is a schematic view in which high-density light is incident on a cylindrical photoexcitation laser device. Only light 27 having a wavelength selected by a spectral filter 26 such as a cold filter or a cold mirror is incident on the incident windows 2 on both end faces of the cylindrical glass container 25 (rotation-axisymmetric quadratic curved glass container 1). Reflection is removed by the spectral filter 26. A cylindrical laser medium 7 placed with the symmetry axis 6 as the optical axis is fixed to the other end of the glass container 1 with an attachment jig 8, and the outer wall 9 of the glass container 1 has an incident high density to excite the laser medium 7. In order to reflect light, a metal film 10 such as gold, aluminum, or silver or a dielectric multilayer film 10 is deposited. Then, water 12 or silicone oil 13 is circulated inside the glass container 11 as a coolant, and after collecting high-density sunlight 15 collected by an objective mirror or lens from the incident window 2 of the glass container 1 (focal point 21). Or it is made to inject from the entrance window 2 of the glass container 1 before condensing. The incident light 4 reflected many times by the reflective film 10 deposited on the outer wall 9 of the cylindrical glass container 25 excites the laser medium 7 and the laser light 20 is output.

FIG. 4 is a schematic view in which high-density light is incident on a truncated cone type optically pumped laser device. A wavelength selective film 3 such as a cold filter or a cold mirror is deposited on the incident windows 2 on both end faces of the truncated cone glass container 27 (rotary axis symmetrical quadratic curved glass container 1), and only the excitation light 4 is incident thereon. The light is reflected and removed. A cylindrical laser medium 7 placed with the symmetry axis 6 as the optical axis is fixed to the other end of the glass container 1 with an attachment jig 8, and the outer wall 9 of the glass container 1 has an incident high density to excite the laser medium 7. In order to reflect light, a metal film 10 such as gold, aluminum, or silver or a dielectric multilayer film 10 is deposited. Then, water 12 or silicone oil 13 is circulated inside the glass container 11 as a coolant, and high-density sunlight 15 collected by an objective mirror or lens from the incident window 2 of the glass container 1 is incident on the incident window 2 of the glass container 1. To the rear of the entrance window 2 so that the focal point 21 is formed. The incident light 4 reflected many times by the reflective film 10 deposited on the outer wall 9 of the truncated cone-shaped glass container 27 excites the laser medium 7 and the laser light 20 is output.

FIG. 5 is a schematic diagram of an optically pumped laser apparatus when the resonator portion of the laser medium is taken out of the integrating sphere glass container. A wavelength selective film 3 such as a cold filter or a cold mirror is deposited on the incident windows 2 on both end faces of the integrating sphere type glass container 24 (rotation-axisymmetric quadratic curved glass container 1), and only the excitation light 4 is incident. The light is reflected and removed. A cylindrical laser medium 7 placed with the symmetry axis 6 as the optical axis at both ends of the glass container 1 is fixed by an attachment jig 8, and the resonator portion of the laser medium is brought out of the integrating sphere glass container. A metal film 10 such as gold, aluminum, silver, or a dielectric multilayer film 10 is deposited on the outer wall 9 of the glass container 1 in order to reflect incident high-density light to excite the laser medium 7. Then, water 12 or silicone oil 13 is circulated in the glass container 11 as a coolant, and the high-density sunlight 15 collected by the objective mirror or the lens 23 from the incident window 2 of the glass container 1 is collected (focal point 21). ) It enters from the entrance window 2 of the glass container 1. The incident light 4 reflected many times by the reflective film 10 deposited on the outer wall 9 of the integrating sphere glass container 27 excites the laser medium 7 and the laser light 20 is output.

FIG. 6 is a schematic diagram of an optically pumped laser device when the resonator portion of the laser medium is taken out of the cylindrical glass container. A wavelength selective film 3 such as a cold filter or a cold mirror is deposited on the incident windows 2 on both end faces of the cylindrical glass container 25 (rotation-axisymmetric quadratic curved glass container 1), and only the excitation light 4 is incident. Light is reflected off. A cylindrical laser medium 7 placed with the symmetry axis 6 as the optical axis at both ends of the glass container 1 is fixed by an attachment jig 8, and the resonator portion of the laser medium is brought out of the integrating sphere glass container. A metal film 10 such as gold, aluminum, silver, or a dielectric multilayer film 10 is deposited on the outer wall 9 of the glass container 1 in order to reflect incident high-density light to excite the laser medium 7. Then, water 12 or silicone oil 13 is circulated in the glass container 11 as a coolant, and the high-density sunlight 15 collected by the objective mirror or the lens 23 from the incident window 2 of the glass container 1 is collected (focal point 21). ) It enters from the entrance window 2 of the glass container 1. The incident light 4 reflected many times by the reflective film 10 deposited on the outer wall 9 of the cylindrical glass container 25 excites the laser medium 7 and the laser light 20 is output.

FIG. 7 is a schematic diagram of an optically pumped laser apparatus when the resonator portion of the laser medium is taken out of the truncated cone glass container. A wavelength selective film 3 such as a cold filter or a cold mirror is deposited on the incident windows 2 on both end surfaces of the truncated cone glass container 27 (rotation-axisymmetric quadratic curved glass container 1), and only the excitation light 4 is incident. Light is reflected off. A frustoconical laser medium 7 placed with the axis of symmetry 6 as the optical axis is fixed to both ends of the glass container 1 with an attachment jig 8, and the resonator portion of the laser medium is brought out of the frustoconical glass container. A metal film 10 such as gold, aluminum, silver, or a dielectric multilayer film 10 is deposited on the outer wall 9 of the glass container 1 in order to reflect incident high-density light to excite the laser medium 7. Then, water 12 or silicone oil 13 is circulated in the glass container 11 as a coolant, and the high-density sunlight 15 collected by the objective mirror or the lens 23 from the incident window 2 of the glass container 1 is collected (focal point 21). ) It enters from the entrance window 2 of the glass container 1. The incident light 4 reflected many times by the reflective film 10 deposited on the outer wall 9 of the truncated cone-shaped glass container 27 excites the laser medium 7 and the laser light 20 is output.

FIG. 8 is a schematic diagram in which high-density light is incident on an integrating sphere type optically pumped laser device after spectral separation. Sunlights 22 and 15 collected by a concave mirror or parabolic mirror 28 are converted into parallel rays 30 by a concave lens 29 and then demultiplexed by a spectral prism 31 to separate the excitation wavelength band spectrum of each laser medium by a reflecting mirror 32. After that, the light 33 having the one wavelength is condensed and made incident on the integrating sphere glass container 24. The remaining spectra are collected by a spherical mirror 32 and collected in a reaction device 35 such as a heat source, a photochemical reaction light source, or a solar cell excitation light source.

According to the present invention, the spectrally separated sunlight that has entered the entrance window of a rotationally axisymmetric quadratic curved glass container such as an integrating sphere, cylinder, or truncated cone whose outer wall is coated with a reflective film is passed through cooling water or silicone oil. Therefore, the high-power high-efficiency solar-excited laser device capable of continuous oscillation without causing the laser medium to be thermally destroyed by the concentrated high-density sunlight can be provided.

The collected sunlight is demultiplexed by the spectral prism and used as the excitation light source of the laser medium according to the selected spectrum. It can be provided as a heat source, a solar cell excitation light source or a photochemical reaction light source.

Operation principle diagram of solar pumped laser equipment Schematic diagram in which high-density light is incident on an integrating sphere optically pumped laser device Schematic diagram of high-density light entering a cylindrical optically pumped laser device Schematic diagram in which high-density light is incident on a truncated cone type pumped laser device Schematic diagram of an optically pumped laser device when the resonator part of the laser medium is taken out of the integrating sphere glass container Schematic diagram of an optically pumped laser device when the resonator part of the laser medium is out of the cylindrical glass container Schematic diagram of an optically pumped laser device when the resonator part of the laser medium is moved out of the frustoconical glass container Schematic diagram of high-density light entering the integrating sphere-type optically pumped laser device after spectroscopy

Explanation of symbols

1 Rotating Axisymmetric Secondary Curved Glass Container such as Integral Sphere, Cylinder, or Frustum 2 Incident Window 3 Wavelength Selective Film (Deposition Film) such as Cold Filter and Cold Mirror
4 Excitation light 5 Incident light 6 Axis of symmetry (optical axis)
7 Cylindrical laser medium (laser rod)
8 Mounting jig 9 Glass container outer wall 10 Metal film such as gold, aluminum, silver or dielectric multilayer film 11 Glass container inside 12 Water (cooling) reflective film or part without film 13 Silicone oil (cooling)
14 Cooling solution entrance / exit 15 High-density sunlight focused by an objective mirror or lens or high-density sunlight dispersed 16 Dielectric reflection film (laser resonator)
17 Cylindrical laser medium side surface 18 Laser light extraction window 19 Amorphous SiO2 protective film (antireflection film)
20 Laser light output 21 Focus 22 Sunlight 23 Objective lens (parabolic mirror, concave mirror, lens, Fresnel lens)
24 Integrating Sphere Glass Container 25 Cylindrical Glass Container 26 Wavelength Selection Filter (Cold Filter, Cold Mirror, Band Pass Filter)
27 Frustum glass container 28 Spherical mirror (parabolic mirror, concave mirror)
29 Concave lens 30 Parallel light after spectroscopy 31 Spectral prism 32 Concave mirror 33 Wavelength-selected excitation light 34 Light of wavelength other than laser excitation (ultraviolet ray, infrared ray)
35 reaction vessel (heat source, photochemical reaction light source, solar cell excitation light source

Claims (6)

A glass container in which an outer wall is formed of an axially symmetric quadric surface rotated around a symmetric axis, and an incident window through which high-density light is incident is integrally provided on one end surface along the symmetric axis ;
The other end surface along the symmetry axis of the glass container is an exit, and a cylindrical laser medium placed with the symmetry axis as the optical axis,
A solar pumped laser device having
A reflective film that reflects high-density light incident on the glass container is deposited on the outer wall of the glass container ,
Only one valve for entering and exiting the refrigerant is installed at a location near the one end surface and the other end surface of the glass container , and is filled with cooling water or oil as the refrigerant circulating in the glass container,
The solar light pumped laser device for causing incidence of high-density optical before and after condensing the entrance window into the glass container. Oil as the refrigerant, the solar light pumped laser device according to claim 1, characterized in that the silicone oil. The outer wall of the axisymmetric quadratic surface of the glass container is formed on an integrating sphere, cylinder or truncated cone,
The high density light, focused solar light, a xenon lamp light, the solar light pumped laser device according to claim 1, characterized in that a mercury lamp light or semiconductor laser beam. When using the cylindrical laser medium in the cooling water, after applying the silicone oil to the reflective film portion and the cylindrical laser medium side of the incidence window side, characterized in that coating the water-resistant film by photooxidation with vacuum ultraviolet light The solar light excitation laser device according to claim 1 or 2. A wavelength selective film to be a cold filter or cold mirror is deposited on the entrance window,
The focus of the concave mirror and a high density light condensed by the convex lens is located in front of the entrance window of the glass container, high-density light by wavelength selection film was deposited on the entrance window of this is spectrally demultiplexed,
2. The solar light pumped laser device according to claim 1, wherein only a spectrum in an excitation wavelength band of the cylindrical laser medium is incident from an incident window. After converting the high-density light into parallel rays in front of the focal point of the high density light condensed by the concave mirror and a convex lens, is spectrally high-density light demultiplexed by spectroscopic prism,
After separation in the spectral Nomiosu lit or reflector excitation wavelength band of the cylindrical laser medium irradiated by focusing on the cylindrical laser medium,
2. The sunlight-excited laser device according to claim 1, wherein the remaining spectrum is condensed by a spherical mirror and used as a heat source , a photochemical reaction light source, or a solar cell excitation light source.

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