Provided is a method of producing a sulfide solid electrolyte which brings low costs, and large sulfur reducing effect, the method comprising heat-treating material for a sulfide solid electrolyte at a temperature no less than a melting point of elemental sulfur while vibrating the material.

Provided are a method for producing a sulfide solid electrolyte having a high Li ion conductivity, in which the production time can be greatly reduced, and a sulfur-based material that can be used in the production method for a sulfide solid electrolyte. The invention relates to a method for producing a sulfide solid electrolyte containing a lithium element, a sulfur element, a phosphorus element, an iodine element and a bromine element, which includes mixing and grinding lithium sulfide and lithium bromide followed by adding phosphorus sulfide and lithium iodide thereto and reacting them, and relates to a sulfur-based material.

Provided is a glass production method with which oxidation can be suppressed and productivity can be increased. A glass production method according to the present invention includes the steps of: turning a raw material 6 placed in a container 1 into a melt 11; homogenizing the melt 11; removing a gas from the melt 11, wherein at least one of the step of turning the raw material 6 into the melt 11 and the step of homogenizing the melt 11 is performed in an atmosphere of an inert gas or a reducing gas, and in the step of the removing the gas from the melt 11, the inert gas or the reducing gas is removed by setting the temperature of the melt 11 to be lower than the temperature in the step of homogenizing the melt 11.

A method of making an optical fiber with multiple openings comprising the steps of fabricating an extrusion die using additive manufacturing such that the extrusion die has a plurality of channels that combine inside the die into another set of channels, extruding a glass, forming a fiber optic preform having a plurality of longitudinal openings that run the entire length, attaching a barrier layer for pressure application, and stretching the preform into an optical fiber with multiple openings. An extrusion die comprising an additive manufactured material, having a proximal side having openings and having a distal side having openings, wherein the openings of the proximal side are of feed channels, wherein the openings of the distal side are of forming channels, and wherein in side the body of the die, two of the feed channels combine the forming channels.

An apparatus used for the fabrication of fiberoptic waveguides utilizing a novel melting and resolidifying apparatus and method while under microgravity conditions is disclosed. In one embodiment, the optical fiber core has a lower melting point than the cladding and the core is melted and resolidified under microgravity conditions. The molten lower melting point core is thus contained by the higher melting point cladding while under microgravity conditions.

Provided is a glass production method with which oxidation can be suppressed and productivity can be increased. A glass production method according to the present invention includes the steps of: turning a raw material 6 placed in a container 1 into a melt 11; homogenizing the melt 11; removing a gas from the melt 11, wherein at least one of the step of turning the raw material 6 into the melt 11 and the step of homogenizing the melt 11 is performed in an atmosphere of an inert gas or a reducing gas, and in the step of the removing the gas from the melt 11, the inert gas or the reducing gas is removed by setting the temperature of the melt 11 to be lower than the temperature in the step of homogenizing the melt 11.

A metal element-containing sulfide solid electrolyte may suppress H.sub.2S generation. Such a metal element-containing sulfide solid electrolyte may include a lithium element, a sulfur element, a phosphorus element, a halogen element, and at least one metal element selected from metal elements of Groups 3 to 12 and Period 4 or higher of the Periodic Table, in which the molar ratio of the lithium element to the phosphorus element (Li/P) is 2.4 or more and 12 or less, and the molar ratio of the sulfur element to the phosphorus element (S/P) is 3.7 or more and 12 or less.