An optical glass includes La.sup.3+, Zn.sup.2+, Nb.sup.5+, and Ti.sup.4+ as a cation configuring glass. La.sup.3+, Zn.sup.2+, Nb.sup.5+, and Ti.sup.4+ which satisfy 10 cat %≤La.sup.3+≤20 cat %, 10 cat %≤Zn.sup.2+≤60 cat %, 20 cat %≤Nb.sup.5+≤60 cat %, and 0 cat %≤Ti.sup.4+≤40 cat % expressed by cation %.

A method of fabricating a shaped optical element for refracting infrared light. The method can include providing a chalcogenide glass mass within a precision mold, the chalcogenide glass mass having a starting volume that is equal to or less than about 105% of the volume of the shaped optical element, precision molding the chalcogenide glass mass by providing heat and pressure to form the chalcogenide glass mass into a near-net shaped optical element, removing the near-net shaped optical element from the precision mold, and refining the near-net shaped optical element to generate the shaped optical element, the outside diameter of the near-net shaped optical element being less than or equal to 25 μm larger than an outside diameter of the shaped optical element. The near-net shaped optical element can have an outside diameter less than 20 μm greater than the outside diameter of the shaped optical element.

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.

An optical glass includes La.sup.3+, Zn.sup.2+, Nb.sup.5+, and Ti.sup.4+ as a cation configuring glass. La.sup.3+, Zn.sup.2+, Nb.sup.5+, and Ti.sup.4+ which satisfy 10 cat %La.sup.3+20 cat %, 10 cat %Zn.sup.2+60 cat %, 20 cat %Nb.sup.5+60 cat %, and 0 cat %Ti.sup.4+40 cat % expressed by cation %.

A method of controlling an optical element manufacturing apparatus includes: heating a cavity formed of a pair of upper and lower dies to a first temperature where an optical element material softens and becomes formable by the pair of dies; heating the cavity to a second temperature where the optical element material is deformed due to a weight of the optical element material in a state of not being in contact with the upper die, the second temperature being higher than the first temperature; and pressing the pair of dies for transfer of forming surfaces of the pair of dies onto the optical element material, the forming surfaces being outside a range where a forming surface of a die has been transferred by the deformation due to the weight in the state where the optical element material is not in contact with the upper die at the second temperature.