Material for magneto-optical element and faraday rotator using the same

Abstract

Disclosed is a material for a magneto-optical element, which is made of magnetic garnet single crystals being wide in a band width in a 1310 nm band and thereby being capable of coping with the wavelength multiplex communication at the wavelength band, and a Faraday rotator using the same. The material for a magneto-optical element is made of a magnetic garnet having a composition formula expressed by R.sub.3-y-x Sm.sub.y Bi.sub.x Fe.sub.5 O.sub.12, where R is one kind of rare earth elements including yttrium (Y), and "x" and "y" are constants defined by 0.3.ltoreq.x.ltoreq.1.9 and 0.4.ltoreq.y.ltoreq.2.7, the magnetic garnet being formed on a non-magnetic substrate by liquid-phase epitaxial growth. R is preferably one of Y, La, Sm and Lu. The Faraday rotator, which is used in a wavelength range of from 1250 to 1370 nm, is formed by superposing a film A made of LPE magnetic garnet single crystals expressed by a composition formula of R1.sub.3-x Bi.sub.x Fe.sub.5-z Z.sub.z O.sub.12, to a film B made of LPE magnetic garnet single crystals expressed by a composition formula of R2.sub.3-y Sm.sub.y Fe.sub.5 O.sub.12, where R1 is one of Al, In of rare earth elements including Y; Z is one of Al, In and Ga; R2 is one kind of rare earth elements including Bi and Y; and "x", "y" and "z" are constants defined by 0.3.ltoreq.x.ltoreq.1.9, 0.5.ltoreq.y.ltoreq.3 and 0.ltoreq.z.ltoreq.0.5.

Dependencies are inferred from the claim text.