LASERS AND LIGHT-EMITTING-DIODES AS SOURCES FOR FIXED-WAVELENGTH MAGNETOOPTICAL PHASE-MODULATED ELLIPSOMETRY

Fixed-wavelength magneto-optical measurements of hysteresis loops base d on phase modulation techniques is a standard method of investigation for thin ferromagnetic films and multilayers. We show that the most c ommon light source employed, i.e., the multimode 632.8 nm HeNe laser, has very poor stability properties which strongly limit the overall se nsitivity. Solid state diode lasers constitute a good alternative for immediate replacement. New generation, high luminosity light-emitting diodes are an excellent alternative which requires only minor adjustme nts in existing setups. (C) 1995 American Institute of Physics.