Growth and Characterization of Magnetooptic Garnet Films with Planar Uniaxial Anisotropy

Abstract

Thick film garnet Faraday rotators with perpendicular anisotropy have limited utility for variable polarization rotation applications because multi-domain effects result in large effective insertion losses in device applications. Thick film growth of (BiGdLu)3(FeGaAl)5O12 on (100) substrates yields growth-induced anisotropies ranging from positive anisotropy perpendicular domains to negative anisotropy in-plane domains. Planar domains show variable magnetization by domain rotation with a uniform projection of magnetization along the axis of light propagation. This can produce low-loss devices when operated in sub-saturation applications such as magnetic field sensors, variable optical attenuators and polarization controllers.

Magnetic properties of bismuth-substituted neodymium iron garnet films on Gd3Ga5O12(100) substrates determined by ferromagnetic resonance measurements

“…H res as a function of β is calculated numerically in order to evaluate K u , K 1 , and γ. The saturation magnetization M s values for the compositions used in this study were referred to as those for YIG and NIG, 27) and were estimated by assuming bismuth substitution for neodymium sites. 28) K u , K 1 , and γ were obtained as fitting parameters giving the closest theoretical curve to the β dependence of experimentally obtained H res .…”

“…The K 1 values of Bix:NIG films obtained in this analysis were smaller than that of BIG (K 1 = −2.3 × 10 3 erg=cm 3 ) 24) or NIG (K 1 = −1.5 × 10 4 erg=cm 3 ). 27) Figure 7 shows the dependence of the g-factor calculated from γ on bismuth concentration. The g-factor approximately decreased from 2.6 to 2.3 as x increased from 0 to 3.…”

Effects of magnetically induced optical incoherence in arrayed Faraday rotator crystals

“…To maximize sensitivity, ferrimagnetic bismuth doped rare earth iron garnet (Bi:RIG) films were tested based on their large responsivities (a MO $ 10 4 rad/Tm at 1550 nm) and known capabilities in various applications. [4][5][6][7] The Bi:RIG films studied herein were grown through liquid phase epitaxy (LPE) with nominal compositions of (BiGdLu) 3 (FeGa) 5 O 12 . 8 The growth techniques and physical properties of the films have been discussed previously in Ref.…”

“…8 The growth techniques and physical properties of the films have been discussed previously in Ref. 7. In spite of their similar compositions, both in-plane (IP) and out-of-plane (OP) domain geometries occurred in the various Bi:RIG films that were studied.…”

“…In IP films, dM k is a result of coherent domain rotations, while in OP films it is produced by domain wall motion. 3,7 Although compositionally optimized for large a MO , the maximum film thicknesses attainable from the LPE process are generally less than 500 lm. Therefore, to exploit the large value of a MO , L was increased by stacking the films along the optical path in a linear array, as illustrated in Fig.…”