PREPARATION METHOD FOR MAGNETOOPTIC GARNET THICK-FILM SINGLE CRYSTAL

PROBLEM TO BE SOLVED : To provide a method for preparing a magntooptic garnet thick-film single crystal with an insertion loss of 0.01 dB or less in a wavelength range of 1.3-1.6 μm. SOLUTION : The magnetooptic garnet thick-film single crystal is represented by the formula : (R, Bi)3(Fe, M)5O12 (wherein R is at least one element selected from among Y and rare earth elements of Eu, Gd, Ho, and Yb; and M is at least either Al or Ga and its amount may be zero); and a preparation method therefor comprises the step of performing crystal growth on a single crystal substrate by a liquid-phase epitaxial growth method in an atmosphere with an oxygen concentration of 13-16% and the step of heat-treating the resultant magnetooptic garnet thick-film single crystal in an N2 or Ar gas atmosphere containing H2.