JP2008210999A - White light exciting laser device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To excite a laser medium and cool a laser head by using all spectra of sun light, and to oscillate a sun-light excited laser by wastelessly utilizing the irradiation energy of sun light. <P>SOLUTION: Sun light is demultiplexed into infrared, red and other light by a dichroic mirror or the like, the infrared light is used for temperature difference electric generation with use of a semiconductor thermoelectric element, the red light is used for solar cell electric generation, and powers obtained from these rays are used as a power supply of a Peltier cooling element for cooling a laser rod with use of a coolant silicone oil or water. Demultiplexed ultraviolet light is converted to a visible ray with use of a phosphor to excite a laser medium together with direct incident visible light. Consequently, a laser can be continuously oscillated with a high efficiency. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

The present invention relates to a white light excitation 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. Especially with high-power lasers, cooling water often flows between the light source and the laser rod.

As shown in Non-Patent Document 1, a solar-excited solid-state laser is the first in the world to achieve 1.3 W continuous oscillation by CGYoung in the United States in 1966 collecting sunlight with a parabolic mirror and irradiating 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, the 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 puts the laser rod in the core part in 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 order to solve the problem, the present inventor condenses light with a toroidal mirror or a toroidal lens as shown in Patent Document 1. It discloses that circulating sunlight is circulated in a toroidal type glass container with cooling water, and high-density parallel light excitation is performed on the laser rod therein through water. Furthermore, the inventor of the present application disclosed in Patent Document 2 that the light collected by an objective lens or a mirror from one incident window on both end surfaces of an axisymmetric circular glass container such as an integrating sphere, a cylinder, or a truncated cone filled with cooling water or silicone oil. It is disclosed that incident sunlight with a density is incident, the incident light travels inside the glass container, and is reflected many times by a reflective film coated on the outer wall of the glass container to excite the entire laser rod. Therefore, the next remaining problem is the development of a method for efficiently absorbing the broad spectrum of sunlight into the laser rod.

The energy density poured from the sun to the earth is 1 kW / m 2, and a solar cell generates visible light of this energy using the quantum photoelectric effect of a semiconductor. The energy conversion efficiency of a solar cell is the ratio of the energy incident on the solar cell and the electrical output energy of the solar cell, expressed as a percentage. 99% of solar cells currently on the market use silicon-based materials, and the conversion efficiency is 17 to 21% when the battery element is single crystal silicon, 15 to 17% with crystalline silicon, and amorphous silicon 10 to 12%.

The reason why the conversion efficiency of a solar cell is as low as 20% at most is that the solar cell does not mediate thermal energy. The wavelength range of sunlight falling on the earth is 250 to 1800 nm. However, only 400-800nm light is used in solar cells. In particular, single crystal silicon has an excitation wavelength peak of 800 nm, and amorphous silicon has a peak of around 600 nm, which is shifted to a longer wavelength side than the peak wavelength of sunlight 550 nm. Therefore, there are many patent applications for a method of exciting a pigment with a peak wavelength of sunlight of 550 nm and converting it into light having a long wavelength. The study of dye-sensitized solar cells using titanium dioxide as a key component for photoelectric conversion speaks out. For example, Patent Document 3 describes a dye-sensitized solar cell in which a spectral sensitizing dye such as a transition metal complex is adsorbed on the surface of a titanium oxide semiconductor layer doped with metal ions. A solar cell using a dye-sensitized oxide semiconductor fine particle thin film is disclosed in Patent Document 4. However, these dye-sensitized solar cells have not been put into practical use because the absorption wavelength region is narrower than that of silicon.

As an attempt to use light in a short wavelength region that is not used in a solar cell, Patent Document 5 discloses that a non-reflective film deposited on the surface of the solar cell is doped with a rare earth metal such as Eu to thermally diffuse. It is disclosed that light in the wavelength region can be absorbed once by rare earth ions and emitted to the longer wavelength side, and the amount of carriers that efficiently absorbs the emitted light can be excited to perform photoelectric conversion with high efficiency. Has been.

When a thermoelectric element is also called a Peltier element and different types of semiconductors are joined to each other and a current flows, heat is generated at one junction and heat is absorbed at the other junction. This means that the heat absorbed on the one hand is released on the other hand. If the direction of the current is reversed, the heat generation and the heat absorption are reversed. Further, if there is a temperature difference between the two joint surfaces, a potential difference appears, which also functions as a temperature difference power generation element. The present inventor applied a sine wave DC voltage to the thermoelectric element so that the thermoelectric element changes from a positive potential to a negative potential, periodically changes the temperature difference, and gives the thermal change to the rock sample. Non-Patent Document 5 discloses that a device for measuring a thermal constant of rock is made. Further, Patent Document 6 discloses an apparatus that cools a laser mirror by causing a direct current to flow through the element in a state where one of the thermoelectric elements is in close contact with the laser mirror and the other is cooled with cooling water. In addition, Non-Patent Document 6 discloses that a temperature difference in which one of the thermoelectric elements is given a high temperature of 500 ° C. or less and the other is set to 100 ° C. or less is used as a power generation element, and a manufacturing method of the element is disclosed in Patent Document 7. Yes.

Patent Document 8 discloses a method of using both solar power generation and thermoelectric power generation by attaching a thermoelectric element behind a layer that transmits only infrared rays to the back side of a solar cell and a heat absorption layer, and a cooling device behind it. Patent Document 9 discloses a method in which a fin for heat exchange is provided between the back side of the solar cell and the back side of the heat transfer element, and the solar cell and the heat transfer element are cooled to use both solar power generation and thermoelectric power generation. Yes. The central part of the donut shape is a sunlight entrance, and the peripheral part is a Fresnel lens, and the solar energy collected by this lens and the sunlight passing through the opening in the central part are superposed and condensed to form a solar cell or A method of irradiating a thermoelectric element is disclosed in Patent Document 10.

The energy density of sunlight falling on the earth is 1 kW / m 2, and a solar cell generates visible light of this energy using the quantum photoelectric effect of a semiconductor, but its photoelectric efficiency is at most 20%. The easiest way to increase this efficiency is to increase the density of sunlight. As a method of manufacturing a cylindrical mirror, the inventor of the present application makes a mirror mold in which a heat-resistant brick surface is NC-milled into a cylindrical shape, and a glass plate is placed thereon in an electric furnace, and the temperature of the furnace is increased to near the softening point of the glass. Non-Patent Document 7 and Patent Document 11 disclose a method of making a large-diameter spherical mirror by raising and evacuating from the lower part of the mold to adjust the glass surface to a curved surface calculated in advance. This technique was used by Hitachi, Ltd. in the “Development of solar thermal power generation system” as a “cylindrical method mirror” in the Sunshine project of the Ministry of International Trade and Industry of Industrial Technology from April 1974. Is disclosed. Further, the inventor of the present application discloses the use of a toroidal mirror as a condensing mirror in a solar-excited laser in Patent Document 1.

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 rod, high-efficiency laser oscillation can be expected. According to Non-Patent Document 9, since the double clad fiber laser doped with Yb has absorption at 975 nm, it is optically pumped with a high power semiconductor laser diode of 2.2 W to a 20-meter fiber at 100 μφ, that is, 1.3 W output, that is, 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, the wavelength of sunlight or UV light that is not used for excitation is converted to laser excitation light, and the wavelength is longer than the excitation wavelength. It is an urgent need to absorb the long infrared rays in the cooling water or to reflect these infrared rays outside the system with a cold mirror and use them as a heat source.
Japanese Patent Application No. 2005-338425 Japanese Patent Application No. 2006-239990 Japanese Patent Publication No. 8-15097 Japanese Patent Application No. 2001-272252 (Japanese Patent Laid-Open No. 2003-86257) Japanese Patent Application No. 7-027359 (Japanese Patent Laid-Open No. 8-204222) Japanese Patent Application No. 53-024972 Japanese Patent Application No. 2000-399255 (JP 2002-20993) Japanese Patent Application No. 8-264144 (Japanese Patent Laid-Open No. 10-110670) Japanese Patent Application No. 4-324162 (Japanese Patent Laid-Open No. 6-174249) Japanese Patent Application No. 2003-1106 (Japanese Patent Application Laid-Open No. 2004-214491) Japanese Patent Application No. 51-79055 (Japanese Patent Laid-Open No. 53-5647) Japanese Patent Application No. 2003-298124 (Japanese Patent Laid-Open No. 2005-070243) Japanese Patent Application No. 2005-251257 (Japanese Patent Laid-Open No. 2006-104046) 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) Masataka Murahara, Thermal diffusivity of rock measured with thermal semiconductor, Nikkan Kogyo Shimbun, March 30, 1977 Toshiba Press Release, March 29, 2004, Development of heat transfer module that generates electricity using temperature difference between upper and lower surfaces Murahara Masataka and Sugawara Yoshikazu, Applied Physics, Vol. 45, No. 9, 700-703 (1976) Kiyokazu Inagaki, Isao Sumida, Souji Kajiura, Akira Doi, Ryoichiro Oshima, Applied Physics, Vol. 46, No. 10, 1040-1044 (1977) 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 Optical physical property handbook, publisher Asakura Shoten, published on March 20, 1984 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. The inventor of the present application discloses a method in which the inside of a quartz glass container having a spherical surface, a cylinder or a toroidal surface is filled with cooling water and a fiber laser rod is arranged on the outer wall thereof. However, it is difficult to dissipate heat with a cylindrical laser rod with a large core diameter. Unless a large amount of cooling water is cooled with a high-speed flow, the laser rod is subject to thermal destruction. 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 rod. Due to this thermal action, continuous oscillation is impossible.

The inventor of the present application disclosed in Patent Document 2 a high-density light such as sunlight, semiconductor laser light, xenon lamp, or mercury lamp light from which infrared rays were separated from the incident window of an integrating sphere glass container whose outer wall was coated with a reflection film. It is disclosed that it is introduced into the laser rod through water or silicone oil. However, even in this document, ultraviolet rays and visible rays injected into the laser rod have not been effectively used. Further, Patent Document 1 discloses indirect excitation of a laser medium by light emission by long ultraviolet rays by mixing a dye laser medium in cooling water of a solid laser head. However, this method has a drawback in that bubbles are generated around the pigment during circulation and the luminous efficiency is lowered. Therefore, in the present invention, it is an object to use all the spectrum of sunlight to excite the laser medium and cool the laser rod, and to use the energy radiated by sunlight without waste.

As a result of earnest research to achieve the above object, the inventors of the present application consisted of one or a plurality of integrating spheres, cylinders, truncated cones, trumpet tubes, etc. connected to the inside of the glass container filled with cooling water or silicone oil, In the case of a single glass container, one of both end faces is an entrance window, and the other end is an exit of a cylindrical laser rod placed with the symmetry axis as the optical axis. An entrance window can be attached. In the present invention, in order to confine incident white light such as high-density lamp light and sunlight in the optical system, a rotationally axisymmetric quadratic curved glass container represented by an integrating sphere is used. In order to obtain the same effect, it is recommended to use a polyhedron such as a 14, 26, 32, 38, 62-hedron. Among them, a 32-hedron having 20 regular hexagons and 12 regular pentagons can be expected to have the same effect as an integrating sphere. A spherical shape such as uniform propagation of light and sound and dispersion of external force is the best, but the flat surface is simple for bringing the Peltier refrigeration element into close contact with the outer wall of the spherical glass container as in the present invention. Therefore, it is desirable that the inner and outer walls be a 32-hedral glass container, or the inner wall of the glass container is a spherical surface and the outer wall is a 32-sided polyhedron. In the case of a cylindrical glass container, it is desirable that the inner wall be a cylinder and the outer wall be a multifaceted pillar type. A phosphor is applied to the outer wall of the glass container, and a laser rod fixed inside the glass container is used to coat the epithelium with a metal deposition film such as gold, aluminum, silver, or a reflective film such as a dielectric multilayer film. White light such as lamp light or sunlight condensed by an objective mirror or lens from the entrance window of the glass container directly through the coolant can be used effectively. On the other hand, the thermal conductivity of silicone oil is as low as about 1/4 of water and the specific heat is as low as about 1/3 of water. However, while water freezes at 0 ° C, silicone oil shows fluidity even at -65 ° C. . Furthermore, water boils at 100 ° C, but silicone oil does not change to 200 ° C. As disclosed in Patent Document 2 by the inventor of the present application, when water has a wavelength longer than 650 nanometers, the transmittance extremely decreases. 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 rod side, it can be seen that silicone oil has characteristics that cannot be considered with water. If water is used as the cooling water for the solar-excited laser, the water absorbs infrared rays and turns into hot water, which warms the laser rod and leads to thermal destruction. If the temperature of the laser rod increases, the oscillation efficiency also decreases. Therefore, high-speed cooling water is circulated to lower the temperature of the element. If the water for cooling absorbs infrared rays from sunlight and warms the cooling water, nothing will happen. Bubbles are also generated by this heat, and irregular reflection is generated at the interface between the laser excitation light and the reflecting mirror. Although silicone oil has a low viscosity, it has fluidity up to 200 ° C or higher and does not generate gas. Moreover, silicone oil has a defoaming action, so even if foam is generated, it is absorbed by the silicone oil itself. Light scattering does not occur. 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 rod is high. Moreover, water absorbs ultraviolet rays and infrared rays in sunlight, but hardly absorbs silicone oil. In addition, although light excitation of a neodymium-doped yag laser or fiber laser uses a wavelength of 808 nanometers or more, it is inefficient to perform excitation in cooling water. However, efficient excitation is possible in silicone oil.

Cooling simplifies the apparatus by cooling the silicone oil with a Peltier refrigeration element. When a Peltier refrigeration element is also called a thermoelectric element and different types of semiconductors are joined to each other and an electric current is passed, heat is generated at one junction and heat is absorbed at the other junction. This means that the heat absorbed on the one hand is released on the other hand. If the direction of the current is reversed, the heat generation and the heat absorption are reversed. Further, if there is a temperature difference between the two joint surfaces, a potential difference appears, which also functions as a temperature difference power generation element. The present invention is to use all energy radiated by sunlight for laser oscillation. Therefore, light with a wavelength that does not directly participate in the excitation of the laser medium, that is, infrared rays that interfere with the cooling effect, is removed from the system, and the thermoelectric power generation is performed by heating the semiconductor thermoelectric element with the infrared rays. The refrigeration element is activated and used to cool the laser rod. When the laser medium is Nd ³⁺ , temperature difference power generation using semiconductor thermoelectric elements is performed with infrared rays of 820 nm or more, and solar power generation using solar cells is performed with infrared rays of 600 nm to 790 nm. The electric power obtained by these solar thermal power generation and solar power generation is used for the power of Peltier thermoelectric elements. On the short wavelength side of long ultraviolet rays and visible rays, the phosphor is excited and the emitted light is used for exciting the laser rod. Here, the long ultraviolet ray means a wavelength region of 300 to 400 nanometers.

In order to effectively carry out the above-mentioned role, the shape of the container for exciting the laser rod is an integrating sphere, insulator-type sphere, cylinder, truncated cone, trumpet tube, etc. In this way, the incident light does not escape outside the excitation system, the optical axis of the cylindrical laser rod is aligned with the axis of symmetry of the glass container, and a phosphor is applied to the outer wall of the glass container or the outer wall of the laser rod. As a result, a reflective film is deposited on the outermost wall of the glass container, the inside of the glass container is filled with water or silicone oil as a cooling liquid, and is directly cooled from the reflective film layer on the outermost wall of the glass container. In particular, silicone oil does not generate bubbles due to heat, is liquid even at 200 ° C., and is liquid even at −60 ° C. In this way, the device can be cooled to −60 ° C. Therefore, in this application, Peltier refrigeration elements are arranged in a mosaic pattern along the spherical surface on the reflective film layer on the outermost wall of the quadratic curved glass container, and the outer walls of the elements are cooled with cooling water having a double tube structure, or Circulate the coolant and cool with a chiller.

As disclosed in Non-Patent Document 10, trivalent neodymium (Nd ³⁺ ), the most popular solid-state laser medium, is a four-level laser that performs an efficient laser transition at 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 rods are excited with high-density light, the laser element itself becomes high temperature due to excitation light or laser output, and laser oscillation when the cooling is insufficient causes a thermal lens effect or the like in the laser rod, leading to destruction of the medium. Forced cooling is essential to prevent this. Furthermore, in order to photoexcite the laser rod, the refrigerant needs to transmit the excitation light. Silicone oil is the best refrigerant that satisfies both of these requirements.

In order to further increase the excitation efficiency of the laser medium, an integrating sphere, an insulator sphere, a cylinder, a truncated cone, a trumpet tube, or other rotationally axisymmetric quadratic surface or a polyhedral glass container is connected to excite at the excitation wavelength specific to the laser medium. The excitation chamber and the phosphor for indirectly exciting the laser rod are separated into an excitation chamber that is excited by long ultraviolet rays or short-wavelength visible light, and a single cylindrical laser is placed on the axis of symmetry of the glass containers in common. Align the optical axis of the rod, and apply or dope or sinter phosphor on the outer wall of the glass container or laser rod, and deposit a reflective film on the outermost wall of both glass containers. Alternatively, fill with silicone oil and cool directly from the reflective film on the outermost wall of the glass container or indirectly with a Peltier refrigeration element by circulating a coolant. And light enters excluding white light or heat rays, such as lamp light or sunlight condensed by an objective lens and lens from the entrance window opened anywhere in the glass container.

The phosphor coated or sintered on the wall surface of the rotationally axisymmetric quadratic curved glass container, for example, in the case of a laser medium doped with Nd ^3+, has an excitation wavelength of 808 nm, and therefore a phosphor having an emission center near 808 nm. desirable. As disclosed in Non-Patent Document 11, phosphors close to this spectrum are (Sr, Mg) ₃ (PO ₄ ) ₂ : Sn ²⁺ or emission centers having an emission center spectrum of 628 nm at an excitation wavelength of 200 to 360 nm. YVO ₄ : Eu having a spectrum of 620 nm, Y ₂ O ₂ : Eu having an emission center spectrum of 626 nm, or the like is used. In the case of a laser medium doped with Cr3 +, Ce3 +, etc., since the excitation wavelength is around 406 nm or 550 nm, Sr ₂ P ₂ O ₇ : Eu ^{2+ with} an emission center wavelength of 419 nm, CaWO _{4 with an} emission center of 412 nm, Emission center spectrum 495.2 nm, excitation wavelength 200-320 nm LaPO ₄ : Ce ³⁺ , Tb ³⁺ , or excitation wavelength 200-300 nm Ca ₅ (PO ₄ ) ₃ (F, Cl): Sb ³⁺ , Mn ²⁺ , emission (Ba, Eu) (Mg, Mn) Al ₁₀ O ₁₇ having a center spectrum of 513 nm, ZnS: Cu, Al having an emission center spectrum of 530 nm, and ZnS: Cu, Au, Al having an emission center spectrum of 535 nm are desirable. In addition, MgWO ₄ having an emission center spectrum of 480 nm and an excitation wavelength of 200 to 350 nm is desirable as an excitation phosphor because it has light emitters at both 406 nm and 550 nm. By applying these phosphors in a pattern such as a lattice, polka dots, mosaic, etc., and depositing an aluminum reflective film on the epithelium and the outer wall of the glass container, the light that has entered the glass container from the outside in the part where the phosphor does not exist, The light excited and generated by the long ultraviolet rays is also reflected and finally excites the laser rod. Here, the ratio of the phosphor to the reflection film is preferably 30 to 70%.

The collected sunlight is demultiplexed and used as a laser rod excitation light source by the selected spectrum. Of the remaining spectrum, long ultraviolet light excites the phosphor and indirectly photoexcites the laser rod, and infrared light is a semiconductor. Used for temperature difference power generation with thermoelectric elements. What must be noted here is that water absorbs infrared rays and turns into hot water, which heats the laser rod and leads to thermal destruction. If the temperature of the laser rod increases, the oscillation efficiency also decreases. High-speed cooling water will be circulated to reduce the temperature of the device, but nothing will happen if the sunlight is warming up. Therefore, in order to prevent infrared rays from entering the coolant of the laser rod, a dichroic mirror or dichroic filter that reflects infrared rays and transmits long ultraviolet rays and visible rays through the excitation light incident window of the rotationally symmetrical secondary curved glass container or Evaporate an infrared cut filter. And this reflected light is guide | induced to a semiconductor thermoelectric element. Alternatively, a dichroic mirror, dichroic filter, infrared cut filter or cold mirror is placed in front of the excitation light entrance window of the container, where it reflects infrared light and directs it to the semiconductor thermoelectric element, and the transmitted long ultraviolet rays and visible light are cooled from the glass container window. Excites the laser rod through the liquid. Alternatively, when using a dichroic mirror, dichroic filter, or cold mirror that transmits infrared rays and reflects long ultraviolet rays and visible rays, the transmitted infrared rays are guided to a semiconductor thermoelectric element, and the reflected long ultraviolet rays and visible rays are reflected in the window of the glass container. To excite the laser rod through the coolant. When a plurality of rotationally axisymmetric quadratic curved glass containers are connected, they are further split into visible rays and long ultraviolet rays by a dichroic mirror, and then injected into the entrance window of the glass vessel through separate windows. Long UV light indirectly excites the laser rod after exciting the phosphor. For example, when the doped laser medium is Nd ³⁺ , temperature difference power generation is performed with a spectral light of 830 nm or more, and when Cr ³⁺ or Ce ³⁺ is used, temperature difference power generation is performed at 570 nm or more.

In order to efficiently absorb the infrared rays of high-density sunlight with a semiconductor thermoelectric element, one surface of the semiconductor thermoelectric element is coated with an absorber such as graphite or carbon, and the other surface is provided with a cooling fin so that it can be used in cooling water or space. The power generated by the temperature difference from the low temperature generated when in a vacuum as in a space is used as a power source for the Peltier refrigeration element for cooling the laser rod. This solar radiant heat and radiant cooling in vacuum are performed on the front and back of the semiconductor thermoelectric element, so that a highly efficient temperature difference power generation can be performed. Therefore, it is used to cool solar-excited lasers that oscillate in outer space.

According to the present invention, in the spectrum of sunlight, not only the light in the slight wavelength range necessary for laser medium excitation, but also the phosphor rod is excited by long ultraviolet light that has not been used in the past. In addition, red light is used for power generation by solar cells, or infrared light is used for temperature difference power generation by semiconductor thermoelectric elements, and the power obtained from these is passed through silicone oil as a cooling liquid for the laser rod. The laser rod can be oscillated continuously with high efficiency by using it as electric power of the Peltier refrigeration element.

The condensed sunlight is dispersed with a dichroic mirror, dichroic filter, infrared cut filter, cold mirror, etc., the infrared region generates temperature difference power, long ultraviolet light excites the phosphor, and visible light directly excites the laser rod and the sun. By using the battery, the entire spectrum of sunlight can be used for laser oscillation.

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

The operation principle of the white light excitation solar laser device of the present invention will be described with reference to FIG. A wavelength selection plate 3 such as a cold filter, a cold mirror or a dichroic mirror is placed on the front surface of the incident window 2 on both end faces of the rotationally symmetric secondary curved surface such as an integrating sphere, a cylinder or a truncated cone or a polyhedral glass container 1, and sunlight or The infrared rays 5 reflected by the inner wavelength selection plate 3 of the high-density light 4 of white light are collected and irradiated to the absorption plate 7 on the front surface of the semiconductor thermoelectric element 6. A radiator 8 is attached behind the semiconductor thermoelectric element 6 and is cooled with cooling water to perform temperature difference power generation. On the other hand, the visible light 9 transmitted through the wavelength selection plate 3 is coated with the silicon oxide film 11 on the side surface of the laser rod 10. This silicon oxide film 11 is obtained by photo-oxidizing a coated silicone oil in an oxygen atmosphere as disclosed in Patent Documents 12, 13, and 14 and Non-Patent Documents 12 and 13 by the present inventors. It is the film | membrane produced | generated in this way. The incident visible light 9 excites the laser rod 10 while being repeatedly reflected by the aluminum film 12 deposited on the outer wall of the glass container 1. Similarly, the long ultraviolet rays 13 transmitted through the wavelength selection plate 3 excite the laser rod 10 while being repeatedly reflected by the aluminum film 12 deposited on the inner wall and the outer wall of the glass container 1. At this time, the photo-oxide silicon film 11 coated on the side surface of the laser rod 10 is doped with a rare earth element 14 such as Eu or Tb, and a phosphor 15 is applied to the outer wall of the glass container 1 and converted by the long ultraviolet rays 13. The laser rod 10 is re-excited by the generated visible light. A coolant 16 such as water or silicone oil circulates between the laser rod 10 and the inner wall of the glass container 1 through a coolant inlet / outlet 17 and a laser output 18 is output from the end face of the laser rod 10.

FIG. 2 is a schematic diagram of rotationally symmetric secondary curved surfaces of various shapes and a laser oscillator made of a polyhedral glass container. (a) is an insulator sphere, (b) is an integrating sphere, (c) is a trumpet tube, (d) is a truncated cone, (e) is a cylinder, and (f) is a polyhedron, the symmetry axis of each glass container The optical axis of the cylindrical laser rod 10 is placed in the same position. High-density sunlight or white light from which infrared rays have been removed travels from the entrance window 2 attached to the front surface of the glass container 1 through the coolant 16 such as silicone oil or water, and is coated on the outer wall of the glass container 1. An integrating sphere shape is adopted in order to reflect most of the light reflected by the aluminum reflecting film 12 and most of the light is incident on the cylindrical laser rod 10. Although the laser oscillation efficiency is improved as it is, there is also light that is not directly used for excitation of the laser rod, such as incident long ultraviolet light. Therefore, in order to make effective use of the light, long ultraviolet light is used on the outer wall or inner wall of the glass container or The phosphor is coated or doped on the outer wall of the laser rod and converted to laser excitation wavelength light to perform highly efficient laser oscillation. Furthermore, the silicone oil filled in the glass container has no light absorption from −60 ° C. to + 200 ° C. and has a high temperature by directly cooling the cooling liquid from the upper part of the reflective film layer on the outermost wall of the glass container with a Peltier refrigeration element. Used as a coolant for optical materials that do not generate air bubbles.

FIG. 3 is a schematic diagram of a laser oscillator made of a cylindrical glass container with a Peltier refrigeration element. The circulation of the cooling liquid 16 in the cylindrical glass container 1 shown in FIG. 1 is stopped, the Peltier freezing element 19 is brought into close contact with the epithelium of the aluminum reflecting film 12 coated on the outer wall of the glass container 1, and the cooling water 20 is put on the opposite surface. It is circulated and covered with an outer wall 22 having a double pipe structure. Here, the coolant 16 may be water, but is preferably silicone oil. Although silicone oil has a low viscosity, it has fluidity up to 200 ° C or higher, no gas is generated, and silicone oil has a defoaming action. Light scattering does not occur. Water as a refrigerant freezes at 0 ° C. However, since silicone oil can be cooled to -65 ° C, the cooling efficiency of the laser rod is high. Moreover, water absorbs ultraviolet rays and infrared rays in sunlight, but hardly absorbs silicone oil. In addition, although light excitation of a neodymium-doped yag laser or fiber laser uses a wavelength of 808 nanometers or more, it is inefficient to perform excitation in cooling water. However, efficient excitation is possible in silicone oil.

FIG. 4 is an operation principle diagram of a double integrating sphere type white light excitation laser device for solid laser excitation. Let the glass container 23 be a visible light direct excitation part, and let the other glass container 24 be the fluorescent substance 15 excitation visible light conversion part by an ultraviolet-ray. Incidence windows 25 and 26 are provided at arbitrary locations on the respective glass containers 23 and 24, and the optical axis of the cylindrical laser rod 10 is placed so as to coincide with the symmetry axis of the connected glass containers via the cooling liquid 16. A two-connection white light excitation laser device is configured. The high-density sunlight 4 incident on the laser device is incident obliquely on the dichroic mirror 3 having a cutoff wavelength of 900 nm, and the reflected infrared ray 5 is irradiated on the carbon heat collecting plate 7 to generate heat of about 500 ° C. The radiator 8 is cooled with cooling water inside and outside 25 ° C. through the semiconductor thermoelectric element (Toshiba thermoelectric module Gigatopaz) 6, and the electric power generated by the temperature difference of 450 degrees is used as the electric power of the cooling water circulation refrigerator of the laser rod. Using. On the other hand, 250-900 nm long ultraviolet rays 13 having been transmitted through the dichroic mirror 3 and reflected by the dichroic mirror 27 were applied from the incident window 26 to the outer wall of the glass container 1 of the UV-excited phosphor visible light conversion unit 24. It is used for excitation of the phosphor 15 and excitation of rare earth elements doped on the outer periphery of the laser rod 10. The phosphor 15 is coated in a polka dot pattern on the outer wall of the glass container 1 of the phosphor-excited visible light converting unit 24 by ultraviolet rays, and the aluminum reflecting film is applied to the epithelium and the part where the phosphor is not coated, that is, the outermost wall of the glass container 1. The laser rod 10 is excited through the cooling liquid 16 while the incident light is repeatedly reflected many times by the reflective film. On the other hand, the visible light 9 transmitted through the dichroic mirror 27 is reflected by the reflecting mirror 28, passes through the incident window 25, travels through the coolant 16, and is reflected many times by the aluminum reflecting film 12 deposited on the outermost wall of the glass container 1. The laser rod 10 having the outer periphery doped with the phosphor (rare earth Eu) 15 is excited through the coolant 16 while repeating the above. Laser light 18 that effectively uses the entire spectrum of sunlight is output by the excitation units 23 and 24 for each of the separated wavelength regions. Here, if the double integrating sphere type white light excitation solar laser device for solid laser excitation (FIG. 4) is tilted and both incident windows are provided on the side surfaces, the reflection mirror 28 can be omitted. Fig. 5 shows the principle of operation of this double-integrated sphere type white-light-excited solar laser device for exciting a solid-state laser with a side entrance window.

FIG. 6 is a schematic diagram of a laser oscillator made of a double-connected rotationally axisymmetric quadratic curved surface and a polyhedral glass container of each shape. The double glass container includes a visible light excitation unit 24 that directly photoexcites the laser rod 10 and a long ultraviolet excitation unit 23 that excites a phosphor with long ultraviolet rays to convert it into visible light. (g) is a double cylinder with a front entrance window, (h) is a double cylinder with a side entrance window, (i) is a double integration sphere with a front entrance window, (j) is a double integral with a side entrance window. Sphere, (k) is a double insulator sphere with front entrance window, (l) is a double 32 facer with front and side entrance windows, and the symmetry axis of each glass container is the optical axis of cylindrical laser rod 10 Are placed in agreement. The type that enters high-density sunlight along the optical axis of the laser from the front of the resonator of the cylindrical laser rod is named a glass container with front and side entrance windows, and is incident from an oblique direction with respect to the optical axis of the cylindrical laser rod. This type is named with a side entrance window.

FIG. 7 shows a cylindrical white light excitation laser device for Nd: YAG laser excitation. Sunlight 4 collected by a mirror or lens is incident obliquely on an infrared transmission filter 3 having a cutoff wavelength of 900 nm, and the transmitted infrared ray 5 is applied to a carbon heat collecting plate 7 to generate heat of about 500 ° C. The radiator 8 was cooled with cooling water inside and outside 25 ° C. via a semiconductor thermoelectric element (Gigatopaz) 6, and the generated electric power due to the temperature difference of 450 ° C. was used as electric power for the cooling water circulation refrigerator of the laser rod. On the other hand, 250 to 900 nm long ultraviolet rays 13 and visible rays 9 and infrared rays of 900 nm or less reflected by the infrared transmission filter 3 pass through the incident window 2 and travel through the coolant 16 such as water, and are deposited on the outermost wall of the glass container 1. The laser reflecting film 12 reaches the laser rod 10 through the coolant 16 while being repeatedly reflected. However, since Nd: YAG having an excitation wavelength of 808 nm is used for the laser rod 10, the wavelength of 750 to 900 nm is directly set. The light of 250 to 400 nm is used for exciting the phosphor 15 applied to the outer wall of the glass container 1 and for the phosphor 15 in which the outer periphery of the laser rod 10 is doped with rare earth. The phosphor 15 applied to the outer wall of the glass container 1 has (Sr, Mg) ₃ (PO ₄ ) ₂ : Sn ^{2+ with an} emission center of 628 nm or YVO ₄ : Eu with an emission center spectrum of 620 nm or an emission center spectrum of 626 nm. Use Y ₂ O ₂ : Eu etc. On the other hand, a laser device using a phosphor 14 doped with a rare earth element Eu on the outer periphery of the laser rod 10 was made as an experiment. The condensed high-density sunlight 4 incident from the entrance window 2 of the glass container 1 excites the laser rod 10 while being reflected many times by the aluminum reflecting film 12 deposited on the outermost wall of the glass container 1, and lasers. Light 18 is output.

FIG. 8 is a diagram of a double integrating sphere type white light excitation laser apparatus for exciting an Nd: YAG laser. Let the glass container 23 be a visible light direct excitation part, and let the other glass container 24 be the fluorescent substance 15 excitation visible light conversion part by an ultraviolet-ray. Incidence windows 25 and 26 are provided at arbitrary locations on the respective glass containers 23 and 24, and the optical axis of the cylindrical laser rod 10 is placed so as to coincide with the symmetry axis of the connected glass containers via the cooling liquid 16. A concatenated white light excitation laser device is configured. The high-density sunlight 4 incident on the laser device is incident obliquely on the dichroic mirror 3 having a cutoff wavelength of 900 nm, and the reflected infrared ray 5 is irradiated on the carbon heat collecting plate 7 to generate heat of about 500 ° C. The radiator 8 was cooled with cooling water inside and outside 25 ° C. via a semiconductor thermoelectric element (Toshiba thermoelectric module Gigatopaz) 6, and the generated power due to the temperature difference of 450 ° C. was used as power for the cooling water circulation refrigerator of the laser rod. . On the other hand, the 250 to 400 nm long ultraviolet rays 13 reflected by the dichroic mirror 27 pass through the dichroic mirror 3 and the 250 to 400 nm long ultraviolet rays 13 excite the phosphor 15 applied to the outer wall of the glass container 1 of the ultraviolet excitation unit 24 from the incident window 26. And is used for exciting rare earth elements doped on the outer periphery of the laser rod 10. The phosphor (YVO ₄ : Eu) 15 epithelium coated in a polka dot pattern on the outer wall of the glass container 1 and the portion where the phosphor is not coated, that is, the aluminum reflecting film 12 deposited on the outermost wall of the glass container 1 many times. The laser rod (Nd: YAG) 10 is excited through a coolant 16 such as water while being reflected. On the other hand, the visible light 9 transmitted through the dichroic mirror 27 and the infrared rays of 900 nm or less pass through the incident window 25 and travel through the coolant 16 such as water, and many times by the aluminum reflecting film 12 deposited on the outermost wall of the glass container 1. The laser rod 10 (Nd: YAG) is excited by the rare earth element Eu doped on the outer periphery through the coolant 16 while repeating the reflection. The laser light 18 is output by effectively utilizing the entire spectrum of sunlight by the separated excitation units 23 and 24 for each of the separated wavelength regions.

FIG. 9 is a diagram of a double integrating sphere type white light excitation laser apparatus for exciting a Cr: YAG laser. In this figure, since the reflection wavelength and the transmission wavelength of the dichroic mirror 27 of Example 2 (FIG. 8) are reversed, the visible light direct excitation unit 23 of the glass container and the phosphor-excited visible light conversion unit 24 by ultraviolet rays are replaced. There is no difference between laser media. The high-density sunlight 4 incident on the laser device is first incident obliquely on the dichroic mirror 3 having a cutoff wavelength of 600 nm, and the reflected infrared light of 600 nm or more is irradiated on the carbon heat collecting plate 7 and about 500 ° C. The radiator 8 is cooled with cooling water inside and outside 25 ° C. through a semiconductor thermoelectric element (Toshiba thermoelectric module Gigatopaz) 6, and the generated power due to the temperature difference of 450 ° C. is generated by the Peltier refrigeration element for cooling water circulation of the laser rod. Used as power. On the other hand, the 200 to 600 nm light transmitted through the dichroic mirror 3 and the 200 to 350 nm long ultraviolet light 13 transmitted through the dichroic mirror 27 excite the phosphor 15 applied to the outer wall of the glass container 1 of the ultraviolet excitation unit 24 from the incident window 26. Used for. Further, the outer periphery of the laser rod 10 extending over the double integrating spheres 23 and 24 was doped with a rare earth element. How many times the phosphor (LaPO ₄ : Ce, Tb) 15 epithelium coated on the outer wall of the glass container 1 and the part where the phosphor is not coated, that is, the aluminum reflecting film deposited on the outermost wall of the glass container 1 The laser rod (Cr: YAG) 10 is excited through the coolant 16 such as water while being reflected. On the other hand, the visible light 9 having a wavelength of 350 to 600 nm transmitted through the dichroic mirror 27 passes through the incident window 25 and travels through the coolant 16 such as water, and is reflected many times by the aluminum reflecting film 12 deposited on the outermost wall of the glass container 1. The laser rod 10 (Cr: YAG) is excited through the coolant 16 while repeating the above. Further, laser light 18 that effectively utilizes the entire spectrum of sunlight is output by excitation of rare earth elements (Tb) doped in the silicon oxide film on the outer periphery of the laser rod 10.

FIG. 10 is a detailed cross-sectional view of a cylindrical white light excitation laser device with a Peltier refrigerator. This figure shows a cylindrical type, but as a white light excitation laser device 21 that represents all glass containers in which one or a plurality of rotationally symmetric secondary curved surfaces or polyhedrons such as integrating spheres, insulator spheres, truncated cones, and trumpet tubes are connected. The detailed view of the same apparatus 21 from Examples 5 to 27 is used. The optical axis of the cylindrical laser rod 10 is aligned with the rotationally symmetric secondary curved surface or the symmetry axis of the polyhedral glass container 1, and the phosphor 15 is applied or sintered in the form of polka dots on the outer wall of the glass container 1. The silicon oxide film 14 formed on the outer wall is doped with the rare earth element 11, the aluminum reflecting film 12 is deposited on the outermost wall of the glass container, and the inside of the glass container is filled with the silicone oil 29 as the cooling liquid 16, and the outermost wall of the glass container The Peltier refrigeration element 19 is brought into close contact with the reflective film 12, and the cooling water 19 is circulated through the electrical insulating layer on the back surface thereof. Since the cooling part is a curved surface, an electrical insulating film is formed on the aluminum reflecting film 12 deposited on the outermost layer of the glass container 1, and a P-type element and an N-type element inside and outside 5 mm × 5 mm are respectively formed thereon. The electrodes are connected with solder so as to be in series to form a polyhedral curved surface. Then, the electrodes were attached with solder so that the P-type element and the N-type element were in series, and then fixed with a material having thermal conductivity, electrical insulation and water resistance. This Peltier refrigeration element processing was complicated. In general, a flat Peltier refrigeration element is commercially available. Therefore, the inner wall of the cylindrical glass container 1 was formed into a cylinder, the outer wall was processed as a polyhedral column, and a commercially available Peltier refrigeration element was directly adhered. The cover 22 is covered from above, and the cooling water 20 is circulated through the gap at the water inlet / outlet port 17. The secondary cooling water 20 is not limited to silicone oil, and may be oil, gas, or liquid as long as it is a refrigerant. In FIG. 10, the silicone oil is contained. However, since the heat transfer rate of the silicone oil is as low as one third of water, it is necessary to circulate the silicone oil as shown in FIG. The phosphor 15 used here varies depending on the laser medium, but in the case of a Nd-doped Nd: YAG laser, (Sr, Mg) ₃ (PO ₄ ) ₂ : Sn ²⁺ , YVO ₄ : Eu or Y ₂ O ₂ : Use Eu etc. In the case of Cr: YAG laser doped with Cr3 + or Ce3 +, Sr ₂ P ₂ O ₇ : Eu ²⁺ or CaWO ₄ or LaPO ₄ : Ce ³⁺ , Tb ³⁺ or Ca ₅ (PO ₄ ) ₃ (F, Cl): Sb ³⁺ , Mn ²⁺ or (Ba, Eu) (Mg, Mn) Al ₁₀ O, ZnS: Cu, Al, ZnS: Cu, Au, Al, or MgWO ₄ are desirable. Further, an aluminum reflecting film 12 is deposited on the outermost layer of the glass container 1 in order to uniformly irradiate the laser rod with light having a wavelength that directly excites the laser rod or light emitted from the phosphor. In order to increase the amount of reflected light on the reflecting film 12 and to keep the area ratio of the phosphor 15 and the reflecting surface constant, the phosphor 15 is applied at intervals like a polka dot pattern or a grid pattern. . Further, in order to improve excitation efficiency, a rare earth element 14 such as Eu, Tb or Tm is doped in the SiO ₂ film 11 formed on the outer wall of the laser rod 10. A laser output 18 is obtained from the laser rod 10 excited by visible light or long ultraviolet light excluding infrared light incident from the incident window 2 of the white light excitation laser device 21 with Peltier refrigeration element.

FIG. 11 is a schematic diagram of a white light excitation laser focused by a lens. High-density light 4 obtained by condensing white light such as mercury lamp light or sunlight with a lens 30 is incident on an infrared transmission filter 3 having a cutoff wavelength of 900 nm at an oblique incidence, and the transmitted infrared light 5 is transmitted to a carbon heat collecting plate 7. The radiator 8 is cooled with cooling water inside and outside 25 ° C. through a semiconductor thermoelectric element (Gigatopaz) 6 to generate about 450 ° C. temperature difference power generation. On the other hand, long ultraviolet rays 13 of 250 to 900 nm and visible rays 9 and infrared rays of 900 nm or less reflected by the infrared transmission filter 3 are input from the incident window 2 to the white light excitation laser oscillation device 21 with a Peltier refrigeration element. Here, the laser rod 10 uses the power obtained by the semiconductor thermoelectric element 6 and cools the Nd: YAG laser rod through the silicone oil 29 as the cooling liquid by the Peltier freezing element 19 to obtain the laser output 18 with high efficiency. The device was prototyped.

FIG. 12 is a schematic diagram of white light excitation Cr: YAG laser focused by a lens. The high-density light 4 obtained by condensing white light such as mercury lamp light and sunlight with the lens 30 is incident on the dichroic mirror 3 having a cutoff wavelength of 600 nm at an oblique incidence, and the reflected infrared radiation of 600 nm or more is the carbon heat collecting plate 7. The radiator 8 is cooled with cooling water inside and outside 25 ° C. through the semiconductor thermoelectric element (Toshiba Thermoelectric Module Gigatopaz) 6 and the temperature difference power generation of 450 degrees is performed.
On the other hand, the light of 200 to 600 nm that has passed through the dichroic mirror 3 is input to the white light excitation laser oscillation device 21 from the incident window 2, where the laser rod 10 uses the power obtained by the semiconductor thermoelectric element 6 and is supplied by the Peltier refrigeration element 19. An apparatus for producing a laser output 18 with high efficiency by cooling a Cr: YAG laser rod through silicone oil 29 as a coolant was manufactured.

FIG. 12 is a schematic view of a white light excitation laser device condensed by a Fresnel lens. The high-density light 4 obtained by condensing white light such as mercury lamp light or sunlight by the Fresnel lens lens 31 is incident obliquely on the dichroic mirror 3 having a cutoff wavelength of 600 nm, and the reflected infrared rays of 600 nm or more are collected by carbon. The plate 7 is irradiated with the heat generated at about 500 ° C. through the semiconductor thermoelectric element (Toshiba Thermoelectric Module Gigatopaz) 6 and the radiator 8 is cooled with cooling water inside and outside 25 ° C., and this temperature difference power generation of 450 degrees is performed. On the other hand, 250 to 900 nm long ultraviolet rays 13 and visible rays 9 and 900 nm or less infrared rays reflected by the dichroic mirror 3 are input to the white light excitation laser oscillation device 21 from the incident window 2, where the laser rod 10 is obtained by the semiconductor thermoelectric element 6. Using the generated electric power, an Nd: YAG laser rod was cooled by a Peltier refrigeration element 19 through silicone oil 29 as a cooling liquid, and a device for obtaining a laser output 18 with high efficiency was manufactured.

FIG. 14 is a schematic diagram of white light pumped Nd: YAG laser condensed by a meniscus lens. A dichroic filter film 33 that reflects infrared light with a wavelength of 900 nm is reflected on the concave portion of the large-diameter meniscus lens 32 and transmits 250 to 900 nm, and the infrared light 5 reflected by the dichroic filter film is absorbed by the carbon heat collecting plate 7. The heat generation of about 500 ° C. is performed by cooling the radiator 8 with cooling water inside and outside 25 ° C. via a semiconductor thermoelectric element (Gigatopaz) 6, and this temperature difference power generation of 450 degrees is performed. On the other hand, the transmitted long ultraviolet rays 13 of 250 to 900 nm and visible rays 9 and infrared rays of 900 nm or less are input from the incident window 2 to the white light excitation laser oscillation device 21 with a Peltier refrigeration element. Here, the laser rod 10 uses the power obtained by the semiconductor thermoelectric element 6 and cools the Nd: YAG laser rod through the silicone oil 29 as the cooling liquid by the Peltier freezing element 19 to obtain the laser output 18 with high efficiency. The device was prototyped.

FIG. 15 is a schematic diagram of white light excitation Cr: YAG laser focused by a meniscus lens. A dichroic filter film 34 that transmits infrared light having a wavelength of 600 nm and reflects 200 to 600 nm is deposited on the concave portion of the large-diameter meniscus lens 32, and the infrared light 5 that has passed through the dichroic filter film is absorbed by the carbon heat collecting plate 7. The heat generation of about 500 ° C. is performed by cooling the radiator 8 with cooling water inside and outside 25 ° C. via a semiconductor thermoelectric element (Gigatopaz) 6, and this temperature difference power generation of 450 degrees is performed. On the other hand, the reflected 200 to 600 nm long ultraviolet rays 13 and visible rays 9 are input from the incident window 2 to the white light excitation laser oscillation device 21 with a Peltier refrigeration element. Here, the laser rod 10 uses the power obtained by the semiconductor thermoelectric element 6, and the Cr: YAG laser rod is cooled by the Peltier refrigeration element 19 through the silicone oil 29 as a cooling liquid to obtain a laser output 18 with high efficiency. The device was prototyped.

FIG. 16 is a schematic diagram of white light pumped Nd: YAG laser focused by square segment mirrors arranged on a concave pedestal. The high-density sunlight 4 reflected by the square segment mirror 37 arranged on the concave pedestal 36 reflects the infrared light having a wavelength of 900 nm to the convex surface portion of the meniscus convex lens 35 and deposits a dichroic filter film 33 that transmits 250 to 900 nm. The infrared ray 5 reflected by the dichroic filter film is absorbed by the carbon heat collecting plate 7 and the heat generated at about 500 ° C. is cooled by the semiconductor thermoelectric element (Gigatopaz) 6 with the cooling water inside and outside the 25 ° C. This temperature difference power generation of 450 degrees is performed. On the other hand, the transmitted long ultraviolet rays 13 of 250 to 900 nm and visible rays 9 and infrared rays of 900 nm or less are input from the incident window 2 to the white light excitation laser oscillation device 21 with a Peltier refrigeration element. Here, the laser rod 10 uses the power obtained by the semiconductor thermoelectric element 6 and cools the Nd: YAG laser rod through the silicone oil 29 as the cooling liquid by the Peltier freezing element 19 to obtain the laser output 18 with high efficiency. The device was prototyped.

FIG. 17 is a schematic diagram of white light excitation Cr: YAG laser focused by square segment mirrors arranged on a concave pedestal. The high-density sunlight 4 reflected by the square segment mirror 37 arranged on the concave pedestal 36 deposits a dichroic filter film 34 that transmits infrared light having a wavelength of 600 nm and reflects 200 to 600 nm on the convex surface of the meniscus convex lens 35. The infrared rays 5 transmitted through the dichroic filter membrane are absorbed by the carbon heat collecting plate 7, and the heat generated at about 500 ° C. is cooled by the semiconductor thermoelectric element (Gigatopaz) 6 with the cooling water inside and outside 25 ° C. This temperature difference power generation of 450 degrees is performed. On the other hand, the reflected 200 to 600 nm long ultraviolet rays 13 and visible rays 9 are input from the incident window 2 to the white light excitation laser oscillation device 21 with a Peltier refrigeration element. Here, the laser rod 10 uses the power obtained by the semiconductor thermoelectric element 6, and the Cr: YAG laser rod is cooled by the Peltier refrigeration element 19 through the silicone oil 29 as a cooling liquid to obtain a laser output 18 with high efficiency. The device was prototyped.

FIG. 18 is a schematic view of an apparatus for supplying white light collected by square segment mirrors arranged on a concave pedestal to a solar cell, a thermoelectric element, and an excited Nd: YAG laser. The high-density sunlight 4 reflected by the square segment mirror 37 arranged on the concave pedestal 36 reflects the infrared light having a wavelength of 900 nm to the convex surface portion of the meniscus convex lens 35 and deposits a dichroic filter film 33 that transmits 250 to 900 nm. The infrared ray 5 reflected by the dichroic filter film is absorbed by the carbon heat collecting plate 7 and the heat generated at about 500 ° C. is cooled by the semiconductor thermoelectric element (Gigatopaz) 6 with the cooling water inside and outside the 25 ° C. This temperature difference power generation of 450 degrees is performed. On the other hand, long ultraviolet rays 13 of 250 to 900 nm and visible rays 9 and infrared rays of 900 nm or less that have been transmitted are reflected by the bandpass filter 39 to a red wavelength 40 of 600 to 790 nm and enter the solar cell 38 with the radiator 8. The electromotive force generated here is used for the power of the Peltier refrigeration element 19. On the other hand, the light beams 9 and 13 having wavelengths of 250 to 600 nm and 800 to 900 nm are input from the incident window 2 to the white light excitation laser oscillation device 21 with a Peltier refrigeration element. Here, the laser rod 10 uses the power obtained by the semiconductor thermoelectric element 6 and the solar cell 38, and the Nd: YAG laser rod is cooled by the Peltier refrigeration element 19 through the silicone oil 29 as a cooling liquid, so that the laser is highly efficient. A device for obtaining an output 18 was prototyped.

FIG. 19 is a schematic view of an apparatus for supplying white light collected by square segment mirrors arranged on a concave pedestal to a solar cell, a thermoelectric element, and an excited Cr: YAG laser. The high-density sunlight 4 reflected by the square segment mirror 37 arranged on the concave pedestal 36 deposits a dichroic filter film 34 that transmits a wavelength of 600 nm or more and reflects 250 to 600 nm on the convex surface of the meniscus convex lens 35, The light transmitted through the dichroic filter film 34 is transmitted through the band-pass filter mirror 39 through the red wavelength 40 of 600 to 790 nm and is incident on the solar cell 38 with the radiator 8. The infrared ray 5 reflected by the mirror 39 is absorbed by the carbon heat collecting plate 7, and the heat generated at about 500 ° C. is cooled by the semiconductor thermoelectric element (Gigatopaz) 6 and the radiator 8 is cooled with cooling water inside and outside 25 ° C. , This temperature difference power generation of 450 degrees. On the other hand, the 250 to 600 nm long ultraviolet rays 13 and the visible light rays 9 reflected by the dichroic filter film 34 are input from the incident window 2 to the white light excitation laser oscillation device 21 with a Peltier refrigeration element. Here, the laser rod 10 uses the electric power obtained by the semiconductor thermoelectric element 6 and the solar cell 38, and the Cr: YAG laser rod is cooled by the Peltier refrigeration element 19 through the silicone oil 29 as a cooling liquid. A device for obtaining an output 18 was prototyped.

FIG. 20 is a schematic view of an apparatus for supplying the reflected light of the solar cells arranged on the concave pedestal to the thermoelectric element and the excited Cr: YAG laser. A band-pass filter film 39 that transmits light of 600 to 790 nm and reflects other wavelengths is deposited on top of the solar cell segments 38 arranged on the concave pedestal 36. The sunlight reflected by the bandpass filter film is condensed to form high-density light 4, and the infrared rays 5 transmitted through the dichroic mirror 3 are absorbed by the carbon heat collecting plate 7, and the heat generated at about 500 ° C. is absorbed by the semiconductor thermoelectric device. The radiator 8 is cooled with cooling water inside and outside 25 ° C. through the element (gigatopaz) 6, and this 450 ° C. temperature difference power generation is performed. On the other hand, the 250 to 600 nm long ultraviolet rays 13 and the visible light rays 9 reflected by the dichroic mirror 3 are input from the incident window 2 to the white light excitation laser oscillation device 21 with a Peltier refrigeration element. Here, the laser rod 10 uses the electric power obtained by the semiconductor thermoelectric element 6 and the solar cell 38, and the Cr: YAG laser rod is cooled by the Peltier refrigeration element 19 through the silicone oil 29 as a cooling liquid. A device for obtaining an output 18 was prototyped.

FIG. 21 is a schematic view of an apparatus for supplying the reflected light of the solar cells arranged on the concave pedestal to the thermoelectric element and the pumped Nd: YAG laser. A band-pass filter film 39 that transmits light of 600 to 790 nm and reflects other wavelengths is deposited on top of the solar cell segments 38 arranged on the concave pedestal 36. The sunlight reflected by this bandpass filter film is condensed to become high-density light 4, and a dichroic filter film 33 that reflects infrared light having a wavelength of 900 nm on the convex surface of the meniscus convex lens 35 and transmits 250 to 900 nm is deposited. The infrared ray 5 reflected by the dichroic filter film is absorbed by the carbon heat collecting plate 7 and the heat generated at about 500 ° C. is cooled by the semiconductor thermoelectric element (Gigatopaz) 6 with the cooling water inside and outside the 25 ° C. Then, this temperature difference power generation of 450 degrees is performed. On the other hand, 250 to 600 nm and 790 to 900 nm light 9 and 13 transmitted through the dichroic filter film 33 is input from the incident window 2 to the white light excitation laser oscillation device 21 with a Peltier refrigeration element. Here, the laser rod 10 uses the power obtained by the semiconductor thermoelectric element 6 and the solar battery 39, and the Peltier refrigeration element 19 cools the Nd: YAG laser rod through the silicone oil 29 as a cooling liquid, so that the laser is highly efficient. A device for obtaining an output 18 was prototyped.

FIG. 22 is a schematic view of an apparatus for supplying the reflected light of the solar cells arranged on the concave pedestal to the thermoelectric element and the Nd: YAG laser arranged below the concave pedestal. A band-pass filter film 39 that transmits light of 600 to 790 nm and reflects other wavelengths is deposited on top of the solar cell segments 38 arranged on the concave pedestal 36. The sunlight reflected by this bandpass filter film is condensed to form high-density light 4, and a dichroic filter film 34 that transmits infrared light having a wavelength of 900 nm and reflects 250 to 900 nm is deposited on the convex surface of the meniscus convex lens 35. The infrared ray 5 that has passed through the dichroic filter film 34 is absorbed by the carbon heat collecting plate 7, and the heat generated at about 500 ° C. is passed through the semiconductor thermoelectric element (Gigatopaz) 6 to the radiator 8 with cooling water inside and outside 25 ° C. Cool and perform this 450 degree temperature difference power generation. On the other hand, the light 9 and 13 having a wavelength of 250 to 600 nm and 790 to 900 nm reflected by the dichroic filter film 34 is input from the incident window 2 to the white light excitation laser oscillation device 21 with a Peltier refrigeration element. Here, the laser rod 10 uses the power obtained by the semiconductor thermoelectric element 6 and the solar cell 38, and the Nd: YAG laser rod is cooled by the Peltier refrigeration element 19 through the silicone oil 29 as a cooling liquid, so that the laser is highly efficient. A device for obtaining an output 18 was prototyped.

FIG. 23 is a schematic view of an apparatus for supplying the reflected light of the solar cells arranged on a flat pedestal to the thermoelectric element and the excited Nd: YAG laser. A band-pass filter film 39 that transmits light of 600 to 790 nm and reflects other wavelengths is deposited on top of the solar cell segments 38 arranged on the flat base 41. The sunlight reflected by this bandpass filter film is condensed to become high-density light 4, and a dichroic filter film 33 that reflects infrared light having a wavelength of 900 nm on the convex surface of the meniscus convex lens 35 and transmits 250 to 900 nm is deposited. The infrared ray 5 reflected by the dichroic filter film is absorbed by the carbon heat collecting plate 7 and the heat generated at about 500 ° C. is cooled by the semiconductor thermoelectric element (Gigatopaz) 6 with the cooling water inside and outside the 25 ° C. Then, this temperature difference power generation of 450 degrees is performed. On the other hand, 250 to 600 nm and 790 to 900 nm light 9 and 13 transmitted through the dichroic filter film 33 is input from the incident window 2 to the white light excitation laser oscillation device 21 with a Peltier refrigeration element. Here, the laser rod 10 uses the power obtained by the semiconductor thermoelectric element 6 and the solar cell 38, and the Nd: YAG laser rod is cooled by the Peltier refrigeration element 19 through the silicone oil 29 as a cooling liquid, so that the laser is highly efficient. A device for obtaining an output 18 was prototyped.

FIG. 24 is a schematic view of an apparatus for supplying reflected light of a plane mirror arranged on a plane pedestal to a thermoelectric element and an Nd: YAG laser arranged below the plane pedestal. The high-density sunlight 4 reflected by the square segment mirrors 37 arranged on the plane pedestal 41 transmits infrared light having a wavelength of 900 nm to the convex surface portion of the meniscus convex lens 35 and deposits a dichroic filter film 34 that transmits 250 to 900 nm, and this dichroic. The infrared ray 5 that has passed through the filter membrane is absorbed by the carbon heat collecting plate 7, and the heat of about 500 ° C. is cooled by the semiconductor thermoelectric element (Gigatopaz) 6 with the cooling water inside and outside the 25 ° C. Performs a temperature difference of 450 degrees. On the other hand, the 250 to 900 nm long ultraviolet rays 13 and the visible rays 9 reflected by the dichroic filter film 34 are input from the incident window 2 to the white light excitation laser oscillation device 21 with a Peltier refrigeration element. Here, the laser rod 10 uses the power obtained by the semiconductor thermoelectric element 6 and cools the Nd: YAG laser rod through the silicone oil 29 as the cooling liquid by the Peltier freezing element 19 to obtain the laser output 18 with high efficiency. The device was prototyped. When the segment mirrors are arranged on the plane pedestal as in this embodiment, the distance (height) to the optical system placed on the upper part can be extremely shortened by increasing the inclination angle formed with the plane pedestal of the segment mirror. I can do it.

FIG. 25 is a schematic view of an apparatus for supplying the reflected light of the solar cells arranged on the plane pedestal to the thermoelectric element and the Cr: YAG laser arranged below the plane pedestal. A band-pass filter film 39 that transmits light of 600 to 790 nm and reflects other wavelengths is deposited on top of the solar cell segments 38 arranged on the flat base 41. The sunlight reflected by this bandpass filter film is condensed to form high-density light 4, and a dichroic filter film 34 that transmits infrared light having a wavelength of 790 nm or more and reflects 250 to 600 nm is deposited on the convex surface of the meniscus convex lens 35. The infrared ray 5 that has passed through the dichroic filter film 34 is absorbed by the carbon heat collecting plate 7, and the generated heat of about 500 ° C. is passed through the semiconductor thermoelectric element (Gigatopaz) 6 to the radiator 8 inside and outside the cooling water at 25 ° C. Cooling with this, this 450 degree temperature difference power generation is performed. On the other hand, the light 9 and 13 having a wavelength of 250 to 600 nm reflected by the dichroic filter film 34 is input from the incident window 2 to the white light excitation laser oscillation device 21 with a Peltier refrigeration element. Here, the laser rod 10 uses the electric power obtained by the semiconductor thermoelectric element 6 and the solar cell 38, and the Cr: YAG laser rod is cooled by the Peltier refrigeration element 19 through the silicone oil 29 as a cooling liquid. A device for obtaining an output 18 was prototyped.

FIG. 26 is a schematic view of an apparatus for supplying the reflected light of the solar cells arranged on the flat pedestal to the thermoelectric element and the excited Cr: YAG laser. A band-pass filter film 39 that transmits light of 600 to 790 nm and reflects other wavelengths is deposited on top of the solar cell segments 38 arranged on the flat base 41. The sunlight reflected by this bandpass filter film is condensed to become high-density light 4, and a dichroic mirror 3 that transmits a wavelength of 600 nm or more is placed, and the infrared rays 5 transmitted by the dichroic mirror 3 are carbon heat collecting plates. 7, the heat generated at about 500 ° C. is cooled by cooling water inside and outside 25 ° C. through the semiconductor thermoelectric element (Gigatopaz) 6, and this temperature difference power generation of 450 degrees is performed. On the other hand, the 250 to 600 nm long ultraviolet rays 13 and the visible light rays 9 reflected by the dichroic mirror 3 are input from the incident window 2 to the white light excitation laser oscillation device 21 with a Peltier refrigeration element. Here, the laser rod 10 uses the electric power obtained by the semiconductor thermoelectric element 6 and the solar cell 38, and the Cr: YAG laser rod is cooled by the Peltier refrigeration element 19 through the silicone oil 29 as a cooling liquid. A device for obtaining an output 18 was prototyped.

FIG. 27 is a schematic view of an apparatus for supplying the reflected light of the belt-like plane mirrors arranged on the plane pedestal to the solar cell and the thermoelectric elements arranged below the plane pedestal and the Cr: YAG laser. A band which transmits light of 600 to 790 nm and reflects other wavelengths on the upper part of the solar cell segment 38 in which the band-like plane mirror 42 arranged on the plane pedestal 41 is mounted on the band-like concave pedestal 43 having the water-cooled tube 8. A pass filter film 39 is deposited. The sunlight reflected by the bandpass filter film 39 is condensed to become high-density light 4 and is condensed on the dichroic mirror 3 attached to the central portion of the flat base 41. The infrared rays 5 of 790 nm or more reflected by the dichroic mirror 3 are absorbed by the carbon heat collecting plate 7, and the heat generated at about 500 ° C. is cooled by the semiconductor thermoelectric element (Gigatopaz) 6 to the inside and outside of the radiator 8 at 25 ° C. Cooling with water, this temperature difference power generation of 450 degrees is performed. On the other hand, the light 9 and 13 having a wavelength of 250 to 600 nm transmitted through the dichroic mirror 3 is input from the incident window 2 to the white light excitation laser oscillation device 21 with a Peltier refrigeration element. Here, the laser rod 10 uses the electric power obtained by the semiconductor thermoelectric element 6 and the solar cell 38, and the Cr: YAG laser rod is cooled by the Peltier refrigeration element 19 through the silicone oil 29 as a cooling liquid. A device for obtaining an output 18 was prototyped.

ADVANTAGE OF THE INVENTION According to this invention, the laser apparatus which used effectively all the spectrum which sunlight has can be provided.

According to the present invention, among the wavelengths of sunlight, not only the light in the slight wavelength range necessary for laser medium excitation, but also the phosphor rod is excited by long ultraviolet light that has not been used in the past. In addition, red light is used for power generation by solar cells, or infrared light is used for temperature difference power generation by semiconductor thermoelectric elements, and the power obtained from these is used as water for cooling the laser rod or silicone oil. Thus, it is possible to provide a laser device that can be used as electric power for the Peltier refrigeration element and can continuously oscillate the laser rod with high efficiency.

Operation principle diagram of white light excitation laser device Schematic diagram of laser oscillator made of rotationally symmetrical secondary curved surface and polyhedral glass container of each shape Schematic diagram of laser oscillator made of cylindrical glass container with Peltier refrigeration element Operation principle diagram of double integrating sphere type white light excitation laser device for solid laser excitation Operation principle diagram of a double integrating sphere type white light pumped laser device for pumping solid state laser with side entrance window Schematic diagram of a laser oscillator made of a double coupled rotationally symmetric quadric surface and a polyhedral glass container of each shape Cylindrical white light pump laser device for pumping Nd: YAG laser (Example 1) Nd: YAG laser excitation double integrating sphere type white light excitation laser device (Example 2) Example 2: A double integrating sphere type white light excitation laser device for exciting a Cr: YAG laser Detailed sectional view of cylindrical white laser device with Peltier refrigeration element (Example 4) Example of white light pumped Nd: YAG laser focused by lens (Example 5) Example of white light pumped Cr: YAG laser focused by lens (Example 6) Example of white light pumped Cr: YAG laser focused by Fresnel lens (Example 7) Example of white light pumped Nd: YAG laser focused by a meniscus lens (Example 8) Example of white-light-excited Cr; YAG laser focused by a meniscus lens (Example 9) Example of white light pumped Nd: YAG laser focused by segment mirrors arranged on a concave pedestal (Example 10) Example of white-light-excited Cr: YAG laser focused by segment mirrors arranged on a concave pedestal (Example 11) Schematic diagram of an apparatus for supplying white light condensed by a segment mirror arranged on a concave pedestal to a solar cell, a thermoelectric element, and an excited Nd: YAG laser (Example 12) Schematic diagram of an apparatus for supplying white light condensed by a segment mirror arranged on a concave pedestal to a solar cell, a thermoelectric element, and an excited Cr: YAG laser (Example 13) Schematic diagram of an apparatus for supplying reflected light of solar cells arranged on a concave pedestal to a thermoelectric element and an excited Cr: YAG laser (Example 14) Schematic diagram of apparatus for supplying reflected light of solar cells arranged on concave pedestal to thermoelectric element and pumped Nd: YAG laser (Example 15) Schematic diagram of apparatus for supplying reflected light of solar cells arranged on concave pedestal to thermoelectric element and Nd: YAG laser arranged below concave pedestal (Example 16) Schematic diagram of apparatus for supplying reflected light of solar cells arranged on flat pedestal to thermoelectric element and pumped Nd: YAG laser (Example 17) Schematic diagram of an apparatus for supplying reflected light of a plane mirror arranged on a plane pedestal to a thermoelectric element and an Nd: YAG laser arranged below the plane pedestal (Example 18) Schematic diagram of apparatus for supplying reflected light of solar cells arranged on flat pedestal to thermoelectric element and Cr: YAG laser arranged below flat pedestal (Example 19) Schematic diagram of apparatus for supplying reflected light of solar cells arranged on flat pedestal to thermoelectric element and excitation Cr: YAG laser (Example 20) Schematic diagram of apparatus for supplying reflected light of strip plane mirrors arranged on a plane pedestal to a solar cell, a thermoelectric element arranged below the plane pedestal, and an excited Cr: YAG laser (Example 21)

Explanation of symbols

(A) Insulator sphere (b) Integrating sphere (c) Trumpet tube (d) Frustum (e) Cylinder (f) Polyhedron (32-hedron)
(G) Dual cylinder with front and side entrance windows (h) Dual cylinder with side entrance window (i) Dual integration sphere with front and side entrance windows (j) Dual integration sphere with side entrance window (k) Front -Double insulator sphere with side entrance window (l) Front-Double polyhedron with side entrance window (32 facets)
DESCRIPTION OF SYMBOLS 1 Glass container 2 Incident window 3 Wave plates, such as a cold filter and a cold mirror 4 High-density white light (sunlight)
5 Infrared 6 Semiconductor thermoelectric element 7 Heat collecting plate 8 Radiator 9 Visible light 10 Laser rod 11 Photo-oxidation film (photo-oxidation of silicone oil)
12 Aluminum reflective film 13 Long ultraviolet ray 14 Rare earth element 15 Phosphor 16 Coolant (water / silicone oil)
17 Coolant inlet / outlet 18 Laser output 19 Peltier refrigeration element 20 Cooling water 21 White light excitation laser oscillation device with Peltier refrigeration element 22 Double tube (cooling water outer wall)
DESCRIPTION OF SYMBOLS 23 Visible light excitation part 24 Ultraviolet excitation fluorescent substance Visible light conversion part 25 Visible light incident window 26 Long ultraviolet light incident window 27 Dichroic mirror 28 Reflective mirror 29 Silicone oil 30 Spherical lens 31 Fresnel lens 32 Large-diameter meniscus concave lens 33 Infrared reflective film (dichroic film) filter)
34 Infrared transparent membrane (dichroic filter)
35 Meniscus convex lens 36 Large-diameter concave mirror base 37 Segment mirror 38 Solar cell 39 Bandpass filter 40 Red wavelength (for solar cell excitation)
41 Flat pedestal 42 Strip flat mirror 43 Strip concave pedestal (including cooling water circulation pipe)

Claims (5)

Align the optical axis of the cylindrical laser rod with the axis of symmetry of a glass container in which one or more containers such as integrating spheres, insulator spheres, cylinders, circularly curved surfaces such as truncated cones and trumpet tubes, or polyhedrons are connected. , Apply or sinter or dope a phosphor on the outer or inner wall of the glass container or the outer wall of the laser rod, deposit a reflective film on the outermost wall of the glass container, and fill the glass container with water or silicone oil as a coolant. Cooling the cooling liquid directly from the top of the reflective film on the outermost wall of the glass container with a Peltier refrigeration element or indirectly by circulating the cooling liquid, and excluding infrared rays from the incident window of the glass container and the sun The red wavelength that does not contribute to the excitation of the laser rod by injecting light etc. is used for the excitation of the laser rod. Line performs a temperature difference power generation semiconductor thermoelectric elements, white light excitation laser device, characterized in that provided for the power of the Peltier refrigeration device. The phosphor is applied to the outer wall of the rotationally symmetrical quadratic curved surface or the polyhedral glass container by coating or sintering one or more kinds of phosphors in a pattern, and aluminum is deposited on the outer wall of the glass container containing the phosphor. Or a silicon oxide film formed on the outer wall of a cylindrical laser rod in which a small amount of a phosphor is mixed, or a rare earth element ion is implanted into a silicon oxide film on the outer wall of a laser rod. Item 2. A white light excitation laser device according to Item 1. A multilayer film that reflects infrared rays and transmits long ultraviolet rays and visible rays is deposited on the excitation light incident window of the rotationally axisymmetric quadratic curved surface or polyhedral glass container, or on the front surface of the excitation light incident window of the glass container. By placing a mirror or filter that reflects infrared light and transmits long ultraviolet light and visible light, or a mirror or filter that transmits infrared light and reflects long ultraviolet light and visible light, visible light within the transmitted light to the glass container is For direct excitation of laser rods, long ultraviolet rays excite phosphors and indirectly excite laser rods, and spectrally dispersed infrared rays are used for solar power generation by semiconductor thermoelectric elements. When using a curved glass container or a polyhedral glass container, it is further split into visible light and long ultraviolet light, and then injected into the entrance window of the glass container through a separate window. Line directly length ultraviolet white light excitation laser device according to claim 1, characterized in that after excitation excite the phosphor, indirectly laser rod. 3. The white light excitation laser according to claim 1, wherein the Peltier refrigeration element is closely attached to a reflective film on the outermost wall of the quadric curved surface or polyhedral glass container, and the outer wall of the element is cooled by a cooling pipe. apparatus. The surface of the semiconductor thermoelectric element coated with graphite or carbon absorber is exposed to high temperature due to the infrared rays of sunlight, and the other side with a radiator (cooling fin) is in the cooling water or space. 3. The white light excitation laser device according to claim 1, wherein electric power generated at a temperature difference from a low temperature generated when in a vacuum is used as a power source of the Peltier refrigeration element for cooling the laser rod. .

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