On the use of refractive index diagrams for source-excited anisotropic regions

The usc of refra ctive in dex d iag ra ms in t h e st ud y of plan e wave prop aga t io n in Ullbounded a nd layered a lliso tropi c medi a is reviewed and t hen exten ded t o a cco un t for ce rta in asp ec ts of t he ra di at ioll fro m co nfin ed so urce distributi o ns . Such ite ms as t he radi atio n condition, saddl e poill t locatioll , foc us ing effects, la te ra l ray t ra jectories, Cerenkov radiation , a nd o t hers are interpreted via t he r efractive index plo ts .