A rod-in-tube method for producing a glass preform for use in the fabrication of an optical fiber, which comprises steps of inserting a glass rod (13) as a core material in a glass tube (12) as a cladding material, fusing and closing one end of the cladding material, filling a gap between the core and cladding materials with an atmosphere containing at least one gaseous halogen-containing compound and then heating the core and cladding materials at a temperature not lower than 1,900°C to collapse the gap between them and to fuse them together, from which glass preform, an optical fiber with low attenuation of light transmission is fabricated.

Method for producing glass preform for optical fiber

A preform for fabrication of a glass fiber optical transmission line is prepared by chemical reaction of vapor ingredients within a glass tube. Reaction, which may be between chlorides or hydrides of, for example, silicon and germanium with oxygen, occurs preferentially within a constantly traversing hot zone. Flow rates and temperature are sufficient to result in glass formation in the form of particulate matter on the inner surface of the tube. This particulate matter deposits on the tube and is fused with each passage of the hot zone. Continuous rotation of the tube during processing permits attainment of higher temperatures within the heated zone without distortion of the tube.

Optical fiber fabrication and resulting product

This invention relates to the production of high purity fused silica glass through oxidation or flame hydrolysis of a vaporizable silicon-containing compound. More particularly, this invention is directed to the use of vaporizable, halide-free compounds in said production. In the preferred practice, a polymethylsiloxane comprises said vaporizable, halide-free compound.

Method of making fused silica by decomposing siloxanes

A rare earth element activated complex halide phosphor and a radiation image storage panel having a fluorescent layer comprising the phosphor, which phosphor is represented by the formula: wherein MIII is at least one trivalent metal selected from the group consisting of AI and Ga, each of X, X', X" and X"' is at least one halogen selected from the group consisting of Cl, Br and I, A is at least one rare earth element selected from the group consisting of Eu, Tb, Ce, Tm, Dy, Pr, Ho, Nd, Yb, Er, Gd, Lu, Sm and Y, a, b and c are numbers satisfying the conditions of 0<a<0.1, 0<b<0.1, 0<c<0.1 and 10-4<a+b+c<0.1, and d is a number satisfying the condition of 10-6<d<0.2. The phosphor emits light of high luminance when stimulated by light having a wavelength within the range of 500 to 1100nm after exposure to a radiation such X-rays, ultraviolet rays, cathode rays, or the like. Further, the phosphor exhibits little fading. Accordingly, the radiation image storage panel has high sensitivity and exhibits improved fading property.

Phosphor and radiation image storage panel employing the same

An electro-optical device containing an electrochromic material layer and electrolytic solution interposed between mutually opposed base plates, each having an electrode on the surface thereof, wherein said electrolytic solution consists essentially of (a) an iodide source material as a redox reaction promoter selected from the group consisting of metal iodides and ammonium iodides, and (b) a lactone solvent capable of dissolving the redox reaction promoter, with the proviso that when the iodide ion source material is not also a metal cation source, a cation source material capable of generating H+ or Li+ is further added.

Electro-optic device

Optical transmission lines suitable for transmitting electromagnetic radiation within the visible spectrum and adjoining portions of the infrared and ultraviolet spectra consists of a pure amorphous silica core clad by a pure silica cladding of lowered refractive index relative to the core. Index lowering of the cladding relative to the core is a result of low temperature silica formation, e.g., by chemical vapor deposition. The cladding may manifest a substantial uniform refractive index of a value at least 0.1 percent less than that of the core or may be graded to such a lowered value.

Optical transmission line

Acousto-optic devices dependent for their operation on lead molybdate (PbMoO4) and related compounds show efficiencies comparable to that of devices made from alpha-iodic acid and superior to that of devices constructed of earlier materials such as lithium niobate. Optical deflectors useful in modulators, switches and correlators are described.

Acousto-optic devices using lead molybdate and related compounds

Uniaxial magnetic anisotropy in supposedly isotropic garnet compositions is found to be related to growth direction of the crystal. Wafers cut from crystalline sections, selected such that growth direction is consistent with formation of but a single 211 face, are usefully incorporated in bubble domain devices-a class of magnetic devices in which information is represented by enclosed single domain regions of polarity opposite to that of immediately surrounding material.

Magnetic devices utilizing garnet compositions

TYPE II (THREE LEVEL) TRANSITION METAL LASERS (SUCH AS THOSE DEPENDENT ON CR3+) ARE CONVERTED TO THPE III (FOURLEVEL) BY COUPLING THE TRANSITION METAL ION TO AN APPROPRIATE RARE EARTH ION. SUITABLE RARE EARTH, INCLUDED AS CATIONS OF THE HOST COMPOSITION, INCLUDE CERIUM, EUROPIUM, TERBIUM, PRASEODYMIUM, AND YTTERBIUM.

Rare earth terminated transition metal lasers

The hydrated and deuterated forms of lithium formate are found to be useful nonlinear materials for use over a wavelength range including the visible spectrum. While conversion efficiency is inferior to that of lithium niobate or barium sodium niobate, resistance to radiation damage is significantly greater. Operation at power levels in excess of 106 watts/cm2 has resulted in no perceptible damage. These materials are suitably incorporated in second harmonic generators as well as in other parametric devices.

Uitert Legrand G Van

Papers

Optical transmission line

Acousto-optic devices using lead molybdate and related compounds

Magnetic devices utilizing garnet compositions

Rare earth terminated transition metal lasers

Lithium formate nonlinear devices