Abstract: An evaluation light 100 from a light source 1 is split to obtain a divided evaluation signal 120 and a reference signal 110, the divided evaluation signal 120 and the reference signal 110 being shone, respectively, onto a sample surface 32 and a reference surface 11 that is made of the same material as the sample, after which a reflected divided evaluation signal 121 and a reflected reference signal 111, which are reflected respectively on the sample surface 32 and the reference surface 11, are caused to interfere for analysis of the sample surface 32.

Abstract: A magnetooptic garnet single crystal film for use in a Faraday rotator is Dy.sub.3-x Bi.sub.x Fe.sub.5 O.sub.12 (x=0.2-1). The garnet has a reduced temperature characteristic of the Faraday rotation angle, to thereby insure a reliable and stabilized isolation against temperature variation.

Abstract: The apparatus includes a semiconductor laser diode, a mounting for the laser diode and a casing with a window through which light from the diode passes. The casing hermetically seals the diode. A magneto-optical member is provided between the end face of the laser diode and the window. The magneto-optical member has a spontaneous magnetization oriented in the direction of the light transmission and a magnetic field is applied to saturate the magneto-optical member.

Abstract: A Faraday rotator has a non-magnetic garnet substrate with a ferrimagnetic garnet film epitaxially grown on the substrate. A magnet induces a magnetic field in the film for rotating the plane of polarization of a light-beam which strikes an end surface of the film at a predetermined angle. The substrate and film are composed of a material wherein the difference (.DELTA. a=a.sub.s -a.sub.f) between the lattice constant a.sub.s of the substrate and the lattice constant a.sub.f of the film satisfies .vertline..DELTA.a.vertline..ltoreq. 0.001A (angstrom).