Abstract:
PROBLEM TO BE SOLVED: To provide an optical member which exhibits high transmittance at a short wavelength, especially, at 193 nm or shorter and has other desired characteristics. SOLUTION: The optical member has an optical incident axis and is comprised of OD-doped silica glass having an absorption limit λ (limit) at 165 nm or shorter. In a certain embodiment, the OD-doped silica glass further contains fluorine. In another embodiment, the OD-doped silica glass contains fluorine of less than about 5,000 mass ppm. Furthermore, in another embodiment, the OD-doped silica glass contains Na of less than about 50 mass ppb. In an embodiment, the optical member is a photomask substrate to be used at a wavelength of shorter than 190 nm. COPYRIGHT: (C)2008,JPO&INPIT
Abstract:
PROBLEM TO BE SOLVED: To provide a synthetic silica material having an optical property improved against dependence of transmission on strength of ultra violet radiation, and a manufacturing method of the silica material.SOLUTION: In synthetic silica material having an OH concentration of less than 900 mass ppm, and having Hof from 1×10to 6×10molecular/cm, an annealing treatment which includes 1) heating to 1100°C, 2)then, cooling to 800°C at a rate of 1°C per hour, and 3) furthermore, cooling to 25°C at a rate of 30°C per hour is performed to the synthetic silica material. With this treatment, the synthetic silica has a measured FDT(dK/dF) of less than 5.10×10cm pulse/mJ when exposed to excimer laser at 193 nm.
Abstract:
PROBLEM TO BE SOLVED: To provide a synthetic silica material having a low level of polarization-induced birefringence, a low level of light-induced wavefront distortion, a high level of initial internal transmission, and method for making the same.SOLUTION: The disclosure includes OD-doped synthetic silica glass usable in optical elements for use in lithography at short wavelengths below about 300 nm. The OD-doped synthetic silica glass is found to have significantly lower polarization-induced birefringence value than non-OD-doped silica glass with comparable concentration of OH. Also an optical member comprising such glass and lithographic systems including such optical member are disclosed. The glass is particularly suitable for immersion lithographic systems by virtue of the exceptionally low polarization-induced birefringence values at about 193 nm.
Abstract:
PROBLEM TO BE SOLVED: To provide a low loss optical fiber and a method and an apparatus for manufacturing the same by appropriately selecting the concentration of alkali metal oxide dopant in a core and cladding.SOLUTION: There is provided the method for manufacturing the optical fiber in which a first glass rod is formed, having peak concentration of 20-1,000 ppm of alkali metal oxide comprising K0 and the first glass rod is inserted into a centerline hole of an optical fiber preform to form a composite preform.
Abstract:
PROBLEM TO BE SOLVED: To provide an optical fiber for decreasing optical fiber loss to the lowest level.SOLUTION: An optical fiber includes a silica-based core having a first dopant for selecting from a group comprising germania, fluorine and mixtures thereof as well as a second dopant containing an alkali metal oxide composed of KO in a peak concentration of 20-1,000 ppm. The concentration of the alkali metal oxide varies with a radius of the optical fiber. The concentration of the alkali metal oxide dopant in the core and a clad is properly selected so that the core has the refractive index profile which is the peak relative refractive index ΔMAX of more than 0.2% with the cladding.
Abstract:
An isopipe (13) for forming a glass ribbon (19) by a fusion process is provided which comprises a trough (11) and first and second weirs (1,2). Each weir (1,2) has an aperture (35) that extends along at least part of the weir's length. The apertures (35) can be used to cool the interior of the weirs (1,2) and thus reduce their creep rate. Alternatively, the apertures (35) can include structural members (41,42) to stabilize the weirs. In certain embodiments, the structural members (41,42) do not completely fill the apertures (35) thus allowing for weir stabilization through a combination of mechanical support and internal temperature reduction.
Abstract:
fibra óptica com baixa perda por curvatura. trata-se de uma fibra óptica com baixa perda por macro e microcurvatura. a fibra possui uma primeira região de revestimento interna, com raio externo r~2~ > 8 1 m e índice de refração ~2~, e uma segunda região de revestimento externa que circunda a região de revestimento interna, com índice de refração. ~3~, onde ~1~ > ~3~ > ~2~. a diferença entre ~3~ e ~2~ é maior que 0,01. a fibra apresenta um corte de cabo 22 m menor ou igual a 1.260 nm e r~1~/r~2 maior ou igual a 0,25.