A method for producing a silica glass for photolithography, which comprises the following steps: jetting a starting material gas, an oxygen gas and a hydrogen gas from a burner and depositing and consolidating silica glass powder on a target to form an ingot having a growing direction, where the ingot is grown in such a manner that at least a part of glass synthesis face on the ingot having the silica glass powder deposited and consolidated is a plane substantially perpendicular to the growing direction of the ingot, thereby to obtain the ingot having a portion in which striae are substantially perpendicular to the growing direction of the ingot; and cutting out of the ingot the portion in which the striae are substantially perpendicular to the growing direction of the ingot, thereby to obtain a silica glass having striae which are substantially parallel to each other and are planar.
An optical member made of silica glass manufactured by the direct method where a material gas comprising an organosilicon compound is allowed to react in an oxidizing flame, said optical member having a 2.times.10.sup.14 molecules/cm.sup.3 or less concentration of formyl radical generated by X-ray irradiation whose dose is 0.01 Mrad or more and 1 Mrad or less.
A device for producing optically homogeneous, streak-free quartz glass bodies having a large diameter including a furnace or melting device having an inner chamber with a pair of openings opposite one another. One or more movable burners are displaceable into one of the openings and the respective glass body to be produced is located in the other opening. Both the burner and glass body are movably positioned. In the course of the production of the quartz glass body, a relative movement is effected in the axial and radial directions between the burner and the quartz glass body such that the distance from the burner outlet opening pertaining to the quartz glass body decreases as the distance from the burner to the X-X axis of the quartz glass body increases.
In an exposure apparatus, an exposure object is exposed to light by applying pulsed light that has a wavelength of 300 nm or less and that has been passed through a plurality of optical components. At least one of the plurality of optical components is made of a synthetic silica glass component. The thickness of the synthetic silica glass component, and the energy density per pulse and the pulse width of the pulsed light satisfy the following expression: .tau.I.sup.-2L.sup.-1.7.gtoreq.0.02 (nsmJ.sup.-2cm.sup.2.3pulse.sup.2) wherein L is the thickness (unit: cm) of the synthetic silica glass component, I is the energy density (unit: mJcm.sup.-2pulse.sup.-1) per pulse, and .tau. is the pulse width (unit: ns).
An optical mount substrate and a manufacturing method of the optical mount substrate. An optical fiber guide section for arranging and fixing an optical transfer section, having an optical waveguide or an optical fiber, is formed. An electrical conductivity member is embedded in the optical mount substrate so that it penetrates a first principal plane of an arrangement section for arranging an optical device optically connected with the optical waveguide or the optical fiber on the first principal plane, and a second principal plane of the arrangement section parallel to the first principal plane. The optical fiber guide section and the arrangement section are formed by pressing a mold member to a heated and softened substrate to transfer inversion geometry of the mold member onto the substrate. The electrical conductivity member, having a predetermined shape, is directly pressed onto the heated and softened substrate to embed it into the substrate.
A production method of synthetic silica glass according to the present invention comprises a first step of ejecting a silicon compound and a combustion gas containing oxygen and hydrogen from a burner to effect hydrolysis of the silicon compound in oxyhydrogen flame to produce fine particles of silica glass, and thereafter depositing and vitrifying the fine particles of silica glass on a target opposed to the burner to obtain a synthetic silica glass ingot; a second step of heating the synthetic silica glass ingot or the like obtained in the first step up to a first retention temperature of not less than 900.degree. C., retaining the ingot or the like at the first retention temperature, and cooling the ingot or the like at a temperature decrease rate of not more than 10.degree. C./h down to a temperature of not more than 500.degree. C.; and a third step of heating the synthetic silica glass ingot or the like obtained in the second step up to a second retention temperature of not less than 500.degree. C. nor more than 1100.degree. C., retaining the ingot or the like thereat, and thereafter cooling the ingot or the like at a temperature decrease rate of not less than 50.degree. C./h down to a temperature 100.degree. C. lower than the second retention temperature.
