Heppel, S.S.HeppelWirth, R.R.WirthOff, J.J.OffScholz, F.F.ScholzHangleiter, A.A.HangleiterObloh, H.H.OblohWagner, J.J.WagnerKirchner, C.C.KirchnerKamp, M.M.Kamp2022-03-032022-03-031999https://publica.fraunhofer.de/handle/publica/19509910.1002/(SICI)1521-396X(199911)176:1<73::AID-PSSA73>3.0.CO;2-6In this paper, we present our investigations of the waveguiding properties of various GaInN/GaN-DH and laser structures; particularly with regard to the influence of the substrate. Due to the small refractive index of sapphire and the neccessity of a thick GaN buffer, several higher order modes (up to 30) are guided in a complete laser structure on sapphire. This and the fact, that the nitrides are birefringent, lead to mode coupling phenomena. To support our experimental results we performed calculations with a 4 x 4 transfer-matrix method, taking into account the birefringence of the material. The results are in good qualitative agreement with our experimental data.engroup III-nitridesGruppe III-Nitridesemiconductor laserHalbleiter-Laserblue laserblaue Lasermode couplingModenkopplung621667530journal article