Relation Between Surface Roughness and Specular Reflectance at Normal Incidence

摘要: Expressions relating the roughness of a plane surface to its specular reflectance at normal incidence are presented and verified experimentally. The expressions valid for case when root mean square is small compared wavelength light. If light sufficiently long used, decrease in measured due function only height irregularities. Long-wavelength measurements thus provide simple sensitive method accurate measurement finish. This particularly useful finishes too fine be accurately by conventional tracing instruments. Surface must also considered precise optical measurements. For example, non-negligible systematic error will made even if less than 0.01 wavelength. optically polished surfaces may important visible ultraviolet regions spectrum.