Abstract: A capillary-type lens array having an inorganic glass around a graded index lens, in which a plurality of the graded index lenses and the inorganic glass are physically fused.

Abstract: A perforated quartz glass tube includes a jacket tube containing a quartz glass material, a plurality of cylindrical glass tubes which are inserted into a pore region of the jacket tube along an axial direction of the jacket tube, and contain a quartz glass material having a softening point higher than a softening point of the jacket tube, and a gap member which is inserted into a gap between the cylindrical glass tubes and a gap between the jacket tube and the cylindrical glass tube, and contains a quartz glass material having a softening point lower than a softening point of the cylindrical glass tube.

Abstract: It is an object of the present invention to provide a copper-containing silica glass which emits fluorescence having a peak in a wavelength range of from 520 nm to 580 nm under irradiation of ultraviolet light with a wavelength of 400 nm or less, and which is excellent in long term stability even in the high output use. The copper-containing silica glass is made to have copper of from 5 wtppm to 200 wtppm, which emits fluorescence having a peak in a wavelength range of from 520 nm to 580 nm under irradiation of ultraviolet light with a wavelength ranging from 160 nm to 400 nm, and in which an internal transmittance per 2.5 mm thickness at a wavelength of 530 nm is 95% or more.

Abstract: It is an object of the present invention to provide a copper-containing silica glass which emits fluorescence having a peak in a wavelength range of from 520 nm to 580 nm under irradiation of ultraviolet light with a wavelength of 400 nm or less, and which is excellent in long term stability even in the high output use. The copper-containing silica glass is made to have copper of from 5 wtppm to 200 wtppm, which emits fluorescence having a peak in a wavelength range of from 520 nm to 580 nm under irradiation of ultraviolet light with a wavelength ranging from 160 nm to 400 nm, and in which an internal transmittance per 2.5 mm thickness at a wavelength of 530 nm is 95% or more.

Abstract: It is an object of the present invention to provide a copper-containing silica glass which emits fluorescence having a peak in a wavelength range of from 520 nm to 580 nm under irradiation of ultraviolet light with a wavelength of 400 nm or less, and which is excellent in long term stability even in the high output use. The copper-containing silica glass is made to have copper of from 5 wtppm to 200 wtppm, which emits fluorescence having a peak in a wavelength range of from 520 nm to 580 nm under irradiation of ultraviolet light with a wavelength ranging from 160 nm to 400 nm, and in which an internal transmittance per 2.5 mm thickness at a wavelength of 530 nm is 95% or more.