Table 1.
Magneto-optical properties of several magnetic oxides and challenges for applications in on-chip nonreciprocal photonic devices.
| Magnetic Oxides | Θ (°/cm) at 1550 nm | α (dB/cm) at 1550 nm | FoM(°/dB) at 1550 nm | Challenges |
|---|---|---|---|---|
| Garnets (Y3Fe5O12, (Bi,Y)3Fe5O12, (Ce,Y)3Fe5O12) | −3300 (CeYIG) [73] | 5.8 [73] | 570 | Lattice and thermal mismatch; Impurity phases; Thermal budget |
| Spinel/Hexaferrites (Fe3O4, γ-Fe2O3, CoFe2O4, MgFe2O4, BaFe12O19) | 2.5 × 104 (γ-Fe2O3) [58] | 3.5 × 105 [60] | 0.07 | Absorption due to Fe2+, Co2+, IVCT, ISCT etc. |
| Manganites ((La,Sr)MnO3, (La,Ca)MnO3) | ~2000 (LSMO at 2.6eV) [69] | ~8 × 104 [69] | – | Metallic and optically absorbent due to Mn3+–Mn4+ double exchange |
| Orthoferrites (YFeO3, LaFeO3, BiFeO3) | ~500 [74] | <2 [75] | 250 | Low magnetization in thin films; Birefringence; Thermal budget |
| Nanocrystals (γ-Fe2O3, CoFe2O4 nanocrystals) | 310 [67] | 130 [67] | 2.4 | Relatively low Faraday rotation, superparamagnetism, relatively low FoM |