Special dispersion mechanism of optical glass

Special dispersion mechanism of optical glass is studied deeply in ths paper.The deviation of relative partial dispersion ΔP_{g, F} from normal line is an important parameter to characterize the special dispersion property of optical glass.The optical glass with high absolute value of ΔP_{g, F} can be used to revise secondary spectrum in advanced optical system.The special dispersion phenomenon in visible region is aroused by inherent absorption in the ultraviolet and infrared regions.The shift and strength of inherent absorption peaks have an evident influence on the slope of dispersion curve, which will change the deviation of relative partial dispersion.It is generally thought that the electron transition results in ultraviolet inherent absorption, and libration of molecule or its group leads to infrared inherent absorption.Special dispersion mechanism is studied not only to deeply understand the relationship among composition, microstructure and property of optical glass, but also to develop new optical glasses with more excellent special dispersion property.