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The invention relates to a method for the economic production of a blank for a component made from laser-active quartz glass in any form or dimension. The method comprises the following method steps: a) preparation of a dispersion with a solids content of at least 40 wt. %, comprising SiO2 nanopowde

The invention relates to a method for the economic production of a blank for a component made from laser-active quartz glass in any form or dimension. The method comprises the following method steps: a) preparation of a dispersion with a solids content of at least 40 wt. %, comprising SiO2 nanopowder and doping agents, including a cation of the rare earth metals and transition metals in a fluid, b) granulation by agitation of the dispersion, with removal of moisture to form a doped SiO2 granulate of spherical porous granular particles with a moisture content of less than 35 wt. % and a density of at least 0.95 g/cm3, c) drying and purification of the SiO2 granulate, by heating to a temperature of at least 1000° C. to form doped porous SiO2 grains with an OH content of less than 10 ppm and d) sintering or fusing the doped SiO2 grains in a reducing atmosphere to give the blank made from doped quartz glass.

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The invention claimed is: 1. A method for producing a blank for a component of laser active quartz glass, said method comprising: a) providing a dispersion with a solids content of at least 40% by wt. which contains SiO2 nanopowder and dopants, including a cation of one or more rare earth metals or

The invention claimed is: 1. A method for producing a blank for a component of laser active quartz glass, said method comprising: a) providing a dispersion with a solids content of at least 40% by wt. which contains SiO2 nanopowder and dopants, including a cation of one or more rare earth metals or transition metals in a liquid, b) granulation by moving the dispersion with withdrawal of moisture until a doped SiO2 granulate of spherical porous granulate grains having a moisture content of less than 35% by wt. and a density of at least 0.95 g/cm3 is formed, c) drying and purifying the SiO2 granulate by heating said SiO2 granulate to a temperature of at least 1000° C. so as to form doped porous SiO2 granules having an OH content of less than 10 ppm, and d) sintering the doped SiO2 granules in a reducing atmosphere so as to form the blank of doped quartz glass, wherein said sintering includes a gas pressure sintering, which comprises the following steps: aa) heating the SiO2 granules to a melting temperature of at least 1600° C. while applying and maintaining a negative pressure; bb) holding the SiO2 granules at the melting temperature at an overpressure ranging from 5 bar to 15 bar for a melting period of at least 30 min so as to form the quartz glass blank; cc) cooling the quartz glass blank while maintaining said overpressure. 2. The method according to claim 1 wherein an initial solids content of at least 50% by wt. is set in the dispersion. 3. The method according to claim 1, wherein the SiO2 granulate obtained according to step b) has a BET surface area ranging from 40 m2/g to 70 2/g. 4. The method according to claim 3, wherein the SiO2 granulate obtained according to step b) has a BET surface area of at least 50 m2/g. 5. The method according to claim 1, wherein the spherical porous granulate grains have a grain size of less than 500 μm. 6. The method according to claim 1, wherein the SiO2 granulate is dried and purified in a chlorine-containing atmosphere. 7. The method according to claim 1, wherein the SiO2 granulate is dried and purified at a temperature of at least 1050° C. 8. The method according to claim 1, wherein the drying and purifying of the porous granulate is performed in an oxygen-containing atmosphere. 9. The method according to claim 1, wherein the porous SiO2 granules obtained according to step c) have an OH content of less than one ppm. 10. The method according to claim 1, wherein the porous SiO2 granules obtained according to step c) have a BET surface area of less than 20 m2/g. 11. The method according to claim 1, wherein the SiO2 granules are thermally densified prior to step d). 12. The method according to claim 1, wherein the quartz glass blank is annealed at a temperature of at least 1120° C. for a retention period of at least 40 hours h. 13. The method according to claim 1, wherein the SiO2 granules according to step d) are molten in a mold. 14. The method according to claim 1, wherein the SiO2 blank according to step d) is three-dimensionally homogenized. 15. The method according to claim 1, wherein bulk body with a radially inhomogeneous refractive index distribution is formed from SiO2 granules of different refractive index, and the bulk body is sintered or molten to obtain the SiO2 blank. 16. A method of transmitting laser light, said method comprising: producing a blank for a component of laser active quartz glass, said producing comprising: a) providing a dispersion with a solids content of at least 40% by wt. which contains SiO2 nanopowder and dopants, including a cation of one or more rare earth metals or transition metals in a liquid, b) granulation by moving the dispersion with withdrawal of moisture until a doped SiO2 granulate of spherical porous granulate grains having a moisture content of less than 35% by wt. and a density of at least 0.95 g/cm3 is formed, c) drying and purifying the SiO2 granulate by heating said SiO2 granulate to a temperature of at least 1000° C. so as to form doped porous SiO2 granules having an OH content of less than 10 ppm, and d) sintering the doped SiO2 granules in a reducing atmosphere so as to form the blank of doped quartz glass, wherein said sintering includes a gas pressure sintering, which comprises the following steps: aa) heating the SiO2 granules to a melting temperature of at least 1600° C. while applying and maintaining a negative pressure; bb) holding the SiO2 granules at the melting temperature at an overpressure ranging from 5 bar to 15 bar for a melting period of at least 30 min so as to form the quartz glass blank; cc) cooling the quartz glass blank while maintaining said overpressure; and incorporating said blank into a core material for a fiber and transmitting said laser light through said fiber. 17. A method of transmitting laser light, said method comprising: producing a blank for a component of laser active quartz glass, said producing comprising: a) providing a dispersion with a solids content of at least 40% by wt. which contains SiO2 nanopowder and dopants, including a cation of one or more rare earth metals or transition metals in a liquid, b) granulation by moving the dispersion with withdrawal of moisture until a doped SiO2 granulate of spherical porous granulate grains having a moisture content of less than 35% by wt. and a density of at least 0.95 g/cm3 is formed, c) drying and purifying the SiO2 granulate by heating said SiO2 granulate to a temperature of at least 1000° C. so as to form doped porous SiO2 granules having an OH content of less than 10 ppm, and d) sintering the doped SiO2 granules in a reducing atmosphere so as to form the blank of doped quartz glass, wherein said sintering includes a gas pressure sintering, which comprises the following steps: aa) heating the SiO2 granules to a melting temperature of at least 1600° C. while applying and maintaining a negative pressure; bb) holding the SiO2 granules at the melting temperature at an overpressure ranging from 5 bar to 15 bar for a melting period of at least 30 min so as to form the quartz glass blank; cc) cooling the quartz glass blank while maintaining said overpressure; and incorporating said blank into an optical filter; and transmitting said laser light through said optical filter. 18. A method of transmitting laser light, said method comprising: producing a blank for a component of laser active quartz glass, said producing comprising: a) providing a dispersion with a solids content of at least 40% by wt. which contains SiO2 nanopowder and dopants, including a cation of one or more rare earth metals or transition metals in a liquid. b) granulation by moving the dispersion with withdrawal of moisture until a doped SiO2 granulate of spherical porous granulate grains having a moisture content of less than 35% by wt. and a density of at least 0.95 g/cm3 is formed, c) driving and purifying the SiO2 granulate by heating said SiO2 granulate to a temperature of at least 1000° C. so as to form doped porous SiO2 granules having an OH content of less than 10 ppm, and d) sintering the doped SiO2 granules in a reducing atmosphere so as to form the blank of doped quartz glass, wherein said sintering includes a gas pressure sintering, which comprises the following steps: aa) heating the SiO2 granules to a melting temperature of at least 1600° C. while applying and maintaining a negative pressure; bb) holding the SiO2 granules at the melting temperature at an overpressure ranging from 5 bar to 15 bar for a melting period of at least 30 min so as to form the quartz glass blank; cc) cooling the quartz glass blank while maintaining said overpressure; and incorporating said blank into a cladding tube for a fiber; and transmitting said laser light through said fiber.