Provided is a mold for molding a wafer lens, including an upper mold and a lower mold. The upper mold includes a first molding surface. The first molding surface includes first molding portions. The first molding portion includes a first recessed portion formed by recessing from the first molding surface. The lower mold matches the upper mold. The lower mold includes a second molding surface right facing the first molding surface. The second molding surface includes second molding portions. The second molding portion includes a first protrusion portion protruding from the second molding surface towards the first molding surface. The first molding portions and the second molding portions are disposed in one-to-one correspondence. The first molding portion further includes a second recessed portion formed by recessing from the first molding surface towards a direction facing away from the lower mold. The second recessed portion surrounds the first recessed portion.

A dropping nozzle includes: a flow passage part that includes a flow passage that molten glass passes through; and an opening part that includes an opening that communicates with the flow passage, the opening part dropping the molten glass as a glass drop, wherein the opening includes a plurality of inclined parts in which adjacent inner inclination angles are different from each other in a section parallel to a center axis of the flow passage part, and from among the plurality of inclined parts, a first inclined part that is closest to the flow passage part has an inner inclination angle that is smaller than an inner inclination angle of a second inclined part that is farthest from the flow passage part.

A method of producing an optical element includes: determining, as a reference mold set, a first mold set from among mold sets; determining a set temperature for the reference mold set; acquiring reference data by measuring, by a temperature measurement sensor, a temperature of the reference mold set; measuring, by the temperature measurement sensor, a temperature of a second mold set that is at least one of the mold sets other than the reference mold set; calculating a correction value based on a measurement result obtained by the measuring and on the reference data; determining a set temperature for the second mold set based on the set temperature for the reference mold set and on the correction value; and performing temperature control on the mold sets based on set temperatures determined for the respective mold sets to produce the optical elements.

The present invention provides a manufacturing method of glass formed body and a forming die which make it possible to sufficiently fill a glass material in the forming die and manufacture a glass formed body having a desired shape. The manufacturing method of glass formed body includes: heating a plate-shaped glass material; pressing the heated plate-shaped glass material by the forming die; and cooling and solidifying the glass material transferred shapes of forming surfaces of the forming die by the pressing, wherein planar-view contour shapes of the forming surfaces are non-circular, a gap formed by the forming surfaces is formed so as to become wider from an inner side toward an outer side of the forming surfaces, and pressure distribution occurring in the plate-shaped glass material in the pressing is uniform in a contour region of each of the forming surfaces.

Provided is a method for producing an inexpensive chalcogenide optical element having high performance. An inside of chalcogenide glass is also heated uniformly by heating the chalcogenide glass with an infrared ray (light LI). Therefore, a molded lens LE hardly causes a crack or the like, a work piece WP as a block of the chalcogenide glass can be softened in a short time, and time required for molding can be shortened. In addition, direct heating with an infrared ray (light LI) allows heating and cooling to be performed in a short time. Therefore, an effect of volatilization, oxidation, crystallization, or the like can be reduced, and the lens LE having a high transmittance can be molded. Press molding can be performed while the temperature of the second mold die 12 is lower than that of the glass. Therefore, the lens LE hardly causing fusion and having an excellent appearance can be molded with a low maintenance frequency.