Faraday rotator and magneto-optical element using the same

摘要

Herein disclosed are a Faraday rotator whose Faraday's rotational angle has low temperature-dependency; a method for efficiently preparing the same; a magneto-optical element which makes use of the Faraday rotator and whose characteristic properties are not susceptive to temperature changes; and an optical isolator, which can be provided at a low price. <??>A Faraday rotator consists of a garnet crystal represented by the following compositional formula and having a lattice constant of 12.470 +/-0.013 ANGSTROM : (Tbl-(a+b+c)LnaBibMlc)3(Fel-dM2d)5Ol2 in the formula, Ln is an element selected from the group consisting of rare earth elements other than Tb; M1 represents an element selected from the group consisting of Ca, Mg and Sr; M2 is an element selected from the group consisting of Al, Ti, Si and Ge; and a to d are numerals satisfying the following relations: 0</=a</=0.5, 0<b</=0.2, 0</=c</=0.2 and 0</= d</=0.1.