Patents by Inventor Ewald Moersen
Ewald Moersen has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Patent number: 6989904Abstract: The method for determining local structures in optical materials, especially crystals, includes observing schlieren visually in a material to be tested with divergent white light in a first step; measuring birefringence of polarized laser light in the material to determine local defects and structure faults in the material with a spatial resolution of 0.5 mm or better in a second step if the material is judged to be suitable in the first step and then interferometrically measuring the material to determine the faults in the material by interferometry in a third step if the material is judged to be suitable in the first and second steps. This method can be part of a method for making optical components, especially for microlithography.Type: GrantFiled: June 18, 2003Date of Patent: January 24, 2006Assignee: Schott AGInventors: Ewald Moersen, Axel Engel, Christian Lemke, Guenter Grabosch
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Patent number: 6969502Abstract: In the method for growing large-volume monocrystals crystal raw material is heated in a melting vessel with heating elements to a temperature above its melting point until a melt is formed. A monocrystal is then formed on the bottom of the melting vessel by lowering the temperature at least to the crystallization point. A solid/liquid phase boundary is formed between the monocrystal and the melt. The monocrystal grows towards the melt surface in a direction that is perpendicular to the phase boundary. A vertical axial temperature gradient is produced and maintained between the bottom of the melting vessel and its upper opening and heat inflow and/or heat outflow through side walls of the melting vessel is prevented, so that the solid/liquid phase boundary has a curvature radius of at least one meter. A crystal-growing device for performing this process is also described.Type: GrantFiled: March 2, 2001Date of Patent: November 29, 2005Assignee: Schott GlasInventors: Gunther Wehrhan, Peter Elzner, Ewald Moersen, Richard Schatter, Hans-Joerg Axmann, Thorsten Reichardt
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Patent number: 6891980Abstract: The method for evaluating schlieren in glassy or crystalline optical materials includes irradiating a test sample of the optical material with light and producing a shadow image of the test sample on a projection screen. The shadow image of the test sample is received in an electronic image receiving device, such as a digital camera, and is compared with another shadow image of schlieren obtained with a comparison sample by means of interferometry. Then the optical material of the test sample is evaluated with the help of the comparison results.Type: GrantFiled: March 5, 2002Date of Patent: May 10, 2005Assignees: Schott Glas, Carl Zeiss SMT AGInventors: Michael Gerhard, Frank-Thomas Lentes, Christian Kusch, Wolfgang Singer, Ewald Moersen
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Patent number: 6816326Abstract: The optical system has a first optical element (11,17, 19, 26) and a second optical element (12, 18, 20, 27) having respective plane surfaces and cubic crystal structures, which are arranged next to each other along an optic axis (10) so that one of the crystal axes of each optical element is parallel to the optic axis and the plane surfaces are resting against each other. The first and second optical elements have first and second orientations in relation to the optic axis, which are preferably rotated by a rotation about the optic axis (10) with respect to each other according to the rotational symmetry of the material. At least one of the first optical element and second optical element is pre-stressed by applying a compressive stress (&sgr;,&sgr;,1,&sgr;2) thereto. The compressive stress is applied radially symmetrically in a plane perpendicular to the optic axis (10) and compensates for spatial dispersion.Type: GrantFiled: July 12, 2002Date of Patent: November 9, 2004Assignee: Schott GlasInventors: Kurt Nattermann, Ewald Moersen
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Patent number: 6740159Abstract: A method of making a fracture-resistant large-size calcium fluoride single crystal is described, which is suitable for an optical component for radiation in the far UV range. The calcium fluoride raw material for the single crystal is first melted and subsequently solidified by cooling the melt to form a single crystal. However the calcium fluoride raw material is doped with from 1 to 250, preferably 1 to 100, ppm of strontium, preferably added as strontium fluoride, and contains from 1 to 10 ppm of sodium as well as up to 100 ppm of other impurities.Type: GrantFiled: August 28, 2002Date of Patent: May 25, 2004Assignees: Schott Glas, Carl Zeiss SMT AGInventors: Joerg Kandler, Ewald Moersen, Burkhard Speit, Harry Bauer, Thure Boehm, Eric Eva, Michael Thier, Hexin Wang, Frank Richter, Hans-Josef Paus
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Publication number: 20040021803Abstract: The method for determining local structures in optical materials, especially crystals, includes observing schlieren visually in a material to be tested with divergent white light in a first step; measuring birefringence of polarized laser light in the material to determine local defects and structure faults in the material with a spatial resolution of 0.5 mm or better in a second step if the material is judged to be suitable in the first step and then interferometrically measuring the material to determine the faults in the material by interferometry in a third step if the material is judged to be suitable in the first and second steps. This method can be part of a method for making optical components, especially for microlithography.Type: ApplicationFiled: June 18, 2003Publication date: February 5, 2004Inventors: Ewald Moersen, Axel Engel, Christian Lemke, Guenter Grabosch
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Publication number: 20040008427Abstract: The optical system has a first optical element (11, 17, 19, 26) and a second optical element (12, 18, 20, 27) arranged along an optic axis (10). The optical elements are preferably made from crystalline material with a cubic crystal structure. The first and second optical elements have first and second orientations in relation to the optic axis, which are preferably rotated with respect to each other according to the rotational symmetry of the material. At least one of the first optical element and second optical element is pre-stressed by applying a compressive stress (&sgr;,&sgr;1,&sgr;2) thereto. The compressive stress is applied radially symmetrically relative to the optic axis (10) and compensates for spatial dispersion.Type: ApplicationFiled: July 12, 2002Publication date: January 15, 2004Inventors: Kurt Nattermann, Ewald Moersen
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Patent number: 6603547Abstract: The method for determining radiation stability of a crystal to radiation of a working wavelength to be employed in a subsequent application includes taking a first absorption spectrum (A) of a cleaved piece of the crystal with a given thickness (D) over a predetermined wavelength range from a first wavelength (&lgr;1) to a second wavelength (&lgr;2) by means of a spectrophotometer. Then the cleaved piece of the crystal is irradiated with an energetic radiation source so as to form all theoretically possible color centers (saturation). After the irradiating a second absorption spectrum (B) of the cleaved piece of crystal is taken over the same predetermined wavelength range. Then a surface integral of a difference spectrum of the first absorption spectrum and the second absorption spectrum over the predetermined wavelength range is formed and divided by the thickness (D) to obtain a scaled surface integral value.Type: GrantFiled: October 11, 2001Date of Patent: August 5, 2003Assignee: Schott GlasInventors: Ewald Moersen, Burkhard Speit, Lorenz Strenge, Joerg Kandler
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Publication number: 20030101923Abstract: A method of making a fracture-resistant large-size calcium fluoride single crystal is described, which is suitable for an optical component for radiation in the far UV range. The calcium fluoride raw material for the single crystal is first melted and subsequently solidified by cooling the melt to form a single crystal. However the calcium fluoride raw material is doped with from 1 to 250, preferably 1 to 100, ppm of strontium, preferably added as strontium fluoride, and contains from 1 to 10 ppm of sodium as well as up to 100 ppm of other impurities.Type: ApplicationFiled: August 28, 2002Publication date: June 5, 2003Inventors: Joerg Kandler, Ewald Moersen, Burkhard Speit, Harry Bauer, Thure Boehm, Eric Eva, Michael Thier, Hexin Wang, Frank Richter, Hans-Josef Paus
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Publication number: 20030089307Abstract: The invention relates to a method for growing large-volume monocrystals with a uniform orientation and consisting of a melt of crystal raw material, in a device comprising a sealable housing (10) in which a melting vessel (20) with side walls (22), a bottom (24), a top opening (26) facing said bottom (24) and optionally a lid (28) are located; and at least one heating element (50, 50′). According to said method, a crystal raw material in the melting vessel (20) is heated with heating elements (50, 50′) to a temperature above the melting point until a melt with a surface is formed. A monocrystal is then formed on the bottom of the melting vessel by lowering the temperature to at least the crystallisation point. Said monocrystal forms a solid/liquid interphase with the melt and grows towards the melt surface on said interphase, in a direction that is perpendicular to the interphase.Type: ApplicationFiled: October 23, 2002Publication date: May 15, 2003Inventors: Gunther Wehrhan, Peter Elzner, Ewald Moersen, Richard Schatter, Hans-Joerg Axmann, Thorsten Reichardt
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Publication number: 20020154814Abstract: The method for evaluating schlieren in glassy or crystalline optical materials includes irradiating a test sample of the optical material with light and producing a shadow image of the test sample on a projection screen. The shadow image of the test sample is received in an electronic image receiving device, such as a digital camera, and is compared with another shadow image of schlieren obtained with a comparison sample by means of interferometry. Then the optical material of the test sample is evaluated with the help of the comparison results. A suitable apparatus for performing this method is also described.Type: ApplicationFiled: March 5, 2002Publication date: October 24, 2002Inventors: Michael Gerhard, Frank-Thomas Lentes, Christian Kusch, Wolfgang Singer, Ewald Moersen
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Publication number: 20020105643Abstract: The method for determining radiation stability of a crystal to radiation of a working wavelength to be employed in a subsequent application includes taking a first absorption spectrum (A) of a cleaved piece of the crystal with a given thickness (D) over a predetermined wavelength range from a first wavelength (&lgr;1) to a second wavelength (&lgr;2) by means of a spectrophotometer. Then the cleaved piece of the crystal is irradiated with an energetic radiation source so as to form all theoretically possible color centers (saturation). After the irradiating a second absorption spectrum (B) of the cleaved piece of crystal is taken over the same predetermined wavelength range. Then a surface integral of a difference spectrum of the first absorption spectrum and the second absorption spectrum over the predetermined wavelength range is formed and divided by the thickness (D) to obtain a scaled surface integral value.Type: ApplicationFiled: October 11, 2001Publication date: August 8, 2002Inventors: Ewald Moersen, Burkhard Speit, Lorenz Strenge, Joerg Kandler