Faraday rotator and magneto-optical element using the same

摘要

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 Å:; $PTEXTPDAT(Tb/PDATHILSBPDAT1\−(a\+b\+c)/PDAT/SB/HILPDATLn/PDATHILSBPDATa/PDAT/SB/HILPDATBi/PDATHILSBPDATb/PDAT/SB/HILPDATM1/PDATHILSBPDATc/PDAT/SB/HILPDAT)/PDATHILSBPDAT3/PDAT/SB/HILPDAT(Fe/PDATHILSBPDAT1\−d/PDAT/SB/HILPDATM2/PDATHILSBPDATd/PDAT/SB/HILPDAT)/PDATHILSBPDAT5/PDAT/SB/HILPDATO/PDATHILSBPDAT12/PDAT/SB/HIL/PTEXT$ ;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, 0b≦0.2, 0≦c≦0.02 and 0≦d≦0.1.