Abstract:
Disclosed is an optical fiber having a silica-based core comprising an alkali metal oxide selected from the group consisting of K2O, Na2O, LiO2, Rb2O, Cs2O and mixtures thereof in an average concentration in said core between about 50 and 500 ppm by weight, said core further comprising chlorine and fluorine, wherein the average concentration of fluorine in said core is greater than the average concentration of alkali metal oxide in said core and the average concentration of chlorine in said core is greater than the average concentration of alkali metal oxide in said core; and a silica-based cladding surrounding and directly adjacent the core. By appropriately selecting the concentration of alkali metal oxide dopant in the core and the cladding, a low loss optical fiber may be obtained.
Abstract:
A synthetic quartz glass to be used for vacuum ultraviolet lights having a wavelength of 175 nm or less which is characterized in that it has an OH group content of 100 ppm or less and is substantially free of reducing type defects.
Abstract:
A synthetic quartz glass for optical use, to be used by irradiation with light within a range of from the ultraviolet region to the vacuum ultraviolet region, which contains fluorine, which has a ratio of the scattering peak intensity of 2250 cm -1 (I 2250 ) to the scattering peak intensity of 800 cm -1 (I 800 ), i.e. I 2250 /I 800 , of at most 1 × 10 -4 in the laser Raman spectrum, and which has an absorption coefficient of light of 245 nm of at most 2 × 10 -3 cm -1 .
Abstract:
A silica glass has a structure determination temperature of 1200 K or lower and a hydrogen molecule concentration of 1 × 10 17 molecules/cm 3 or more. The silica glass is used together with light in a wavelength region of 400 nm or shorter.
Abstract translation:二氧化硅玻璃的结构测定温度为1200K以下,氢分子浓度为1×10 17分子/ cm 3以上。 石英玻璃与波长400nm以下的光一起使用。
Abstract:
A synthetic quartz glass optical member for an ultraviolet laser, suitably applicable as a stepper lens of a lithographer using an excimer laser beam and other optical members, wherein the quartz glass has a hydroxyl content of 10 to 100 ppm, a chlorine content of 200 ppm or less, a hydrogen content of 1 x 10 16 molecules/cm 3 or less, a homogeneity of refractive index of 5 x 10- 6 or less in terms of Δn, and a birefringence of 5 nm/cm or less. The optical member can be produced by subjecting a volatile silicon compound to flame hydrolysis with oxyhydrogen flame, depositing the formed particulate silica on a heat-resistant support to prepare a porous silica matrix, heating the matrix in a vacuum as high as 1 x 10- 2 Torr or above to a temperature of 1,400 °C or above to effect dehydration and degassing, homogenizing the resultant transparent quartz glass into highly homogeneous quartz glass free from striae in at least one direction, molding the highly homogeneous quartz glass, and annealing the molded glass.
Abstract:
PROBLEM TO BE SOLVED: To provide an optical fiber preform which can be drawn into an optical fiber with low loss.SOLUTION: An optical fiber preform 1 includes a core part 10 and a clad part 20 surrounding the core part 10. The core part 10 includes a first core part 11 and a second core part 12 surrounding the first core part 11. The clad part 20 includes a first clad part 21 surrounding the second core part 12 and a second clad part 22 surrounding the first clad part 21. The first core part 11 contains an alkali metal element, a density of oxygen molecules included in a glass being 30 to 200 mol ppb in a part or the whole of an area where an alkali metal atom density is 100 atomic ppm or larger and 10 mol ppb or less in an area where an alkali metal atom density is 50 atomic ppm or less.
Abstract:
PROBLEM TO BE SOLVED: To provide an optical member for EUVL (Extreme UltraViolet Lithography) used for a reflection type mask, mirror or the like for EUVL, and in which the flatness and surface roughness of an optical plane are excellent, and also, the chipping of a chamfered part is prevented, and to provide a surface treatment method for the optical plane of an optical member for EUVL. SOLUTION: The surface treatment method for the optical member for EUVL is characterized in that the optical plane of an optical member for EUVL made of a quartz glass material having OH concentration of ≥100 ppm, essentially consisting of SiO 2 and comprising TiO 2 is subjected to GCIB (Gas Cluster Ion Beam) etching using a source gas comprising at least either fluorine or chlorine. COPYRIGHT: (C)2009,JPO&INPIT