TY - JOUR A1 - Schmidt, Frank A1 - März, Reinhard T1 - On the Reference Wave Vector of Paraxial Helmholtz Equations T2 - IEEE Journal of Lightwave Technology Y1 - 1996 UR - https://opus4.kobv.de/opus4-zib/frontdoor/index/index/docId/2386 VL - 14 SP - 2395 EP - 2400 ER -