EntityQ898896· pop 24· linked from 133 articlesnumerical apertureSign in to savedimensionless number that characterizes the range of angles over which the system can accept or emit lightConnectionswavelengthEntityoptical fiberEntityrefractive indexEntityTotal internal reflectionEntityf-numberEntityobjectiveEntitycardinal pointEntitywaterEntityphotographyEntityInternational Standard Book NumberEntityatmosphere of EarthEntityopticsEntitylineEntityWayback MachineEntitydigital object identifierEntityconeEntityUniversity of California, Los AngelesEntityabsolute valueEntityNikonEntitySnell's lawEntityCategoriesDimensionless numbers of physicsFiber opticsMicroscopyOptics