| 摘要 |
Provided are optical glasses having a phosphate-containing composition that can materialize highly useful optical properties including high-refractivity and high-dispersion properties; an optical glass comprising P2O5, SiO2 and Li2O as essential components, comprising Na2O and K2O as optional components, having an Li2O/(Li2O+Na2O+K2O) molar ratio of from 1/3 to 1 and having an Abbe's number (nud) of 30 or less, and an optical glass comprising P2O5, SiO2 and Li2O as essential components, having the property of transmittance that when light is caused to vertically enter one of two plane and mutually parallel optically polished surfaces of a sample of the glass having a thickness of 10.0±0.1 mm and caused to exit from the other surface, the wavelength at which the transmittance represented by the ratio of transmitted light intensity to incidence light intensity (transmitted light intensity/incidence light intensity) comes to be 70% is 510 nm or less, having a refractive index (nd) of 1.80 or more and an Abbe's number (nud) of 30 or less and having a liquidus temperature of less than 1,000° C.
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