( n 1 2 − n 2 2 ) 1/2 MathType@MTEF@5@5@+=feaagCart1ev2aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLnhiov2DGi1BTfMBaeXatLxBI9gBaerbbjxAHXgarqqtubsr4rNCHbGeaGqipG0dh9qqWrVepG0dbbL8F4rqqrVepeea0xe9LqFf0xc9q8qqaqFn0lXdHiVcFbIOFHK8Feea0dXdar=Jb9hs0dXdHuk9fr=xfr=xfrpeWZqaaeqabiGaciGacaqadmaadaqaaqaaaOqaamaabmaabaGaamOBamaaDaaaleaacaaIXaaabaGaaGOmaaaakiabgkHiTiaad6gadaqhaaWcbaGaaGOmaaqaaiaaikdaaaaakiaawIcacaGLPaaadaahaaWcbeqaamaalyaabaGaaGymaaqaaiaaikdaaaaaaaaa@3EC0@
where n1 is the maximum refractive index of the core, and n2 is the refractive index of the innermost homogeneous cladding
où n1 est l'indice de réfraction maximal dans le coeur et n2 l'indice de réfraction de la gaine homogène la plus interne