GLASS MATERIAL FOR MOLD PRESS, METHOD FOR MANUFACTURING THE GLASS MATERIAL, AND METHOD FOR MANUFACTURING GLASS OPTICAL ELEMENT

摘要

This invention provides a glass material for a mold press, comprising a core part formed of a multicomponent optical glass containing at least one easily reducible component selected from W, Ti, Bi, and Nb, and a covering part formed of a multicomponent glass, of which the content of the easily reducible component is lower than that in the core part or is zero, for covering the surface of the core part. There is also provided a glass material for a mold press, comprising a core part formed of a fluorine-containing multicomponent optical glass, and a covering part formed of a multicomponent glass, of which the fluorine content is lower than that in the core part or is zero, for covering the surface of the core part. There is further provided a method for manufacturing a glass optical element, comprising heating the above glass material preformed into a predetermined shape for softening and press-molding the softened glass material using a mold. A method for stably producing an optical element having satisfactory optical properties is provided by using an easily reducible component- or fluorine-containing optical glass to suppress an unnecessary interface reaction in press molding.