光学玻璃.doc

光学玻璃
Optical Glass
OPTICAL GLASS SPECIFICATIONS
Selecting a glass material is important since different glass types have different characteristics. Edmund Optics? offers a wide variety of glass types which can be selected on the basis of the following characteristics.
The index of refraction and Abbe number of a glass are typically used by designers as degrees of freedom when designing systems. The index of refraction refers to the ratio of the speed of light in a vacuum to the speed of light through a given material at a given wavelength, while the Abbe number of a material quantifies the amount of dispersion (variations in index) for a specific spectral range. For instance, a higher index of refraction generally bends light more efficiently so there is less of a need of curvature in the lens. Spherical aberration is less present in lenses with higher indices of refraction, while light travels faster through materials with lower indices of refraction.
A high Abbe number generally gives less color dispersion and reduces color aberration. Also, certain glass types have different transmission wavelength regions.
The density of a glass helps determine the weight of the optical assembly and, along with lens diameter, es critical for weight sensitive applications. Density also generally denotes the ability to work with the glass
and is somewhat proportional to the cost