Growth-Induced Birefringence of Bi-Substituted Iron Garnet Films

Investigations into the relation between the growth-induced birefringence (¿nf^G) and Bi content in Bi garnet films are discussed. BiYMIG (M = Ga, A1) and YIG films were grown by the usual LPE method on {111}GGG substrates. Films with different Bi contents were grown by adjusting the R2 (= Fe2O3/M2O3) and Rs (= PbO/Bi2O3) parameters and the growth temperature (TG = 800 to 900°C). The growth- induced birefringence ¿nf^G was obtained by analyzing the dependence of TE-TM conversion efficiency on the light propagation distance. In contrast to ¿F, ¿n f^G does not depend on the amount of Ga or A1 present. The conclusion was that growth-induced birefringence in this system was due to the inhomogeneous distribution of Bi in the dodecahedral sites.