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What's Optical Glass Specifications?
2024/5/21

Selecting a glass material is important since different glass types have different characteristics. He Rui 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, becomes critical for weight sensitive applications. When dealing with applications involving extreme temperatures and quick temperature differentials, a glass' coefficient of expansion also becomes a key factor. Opto-mechanical designers need to keep this in mind when designing optical assemblies.

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