High Verdet constant Ga : S : La : O chalcogenide glasses for magneto-optical devices

The magneto-optical rotation at room temperature was measured for three Ga: S:La:O chalcogenide glasses at several laser lines in the visible. The firs t sample was a binary system constituted by 70 mol % Ga2S3 and 30 mol % La2 O3, whereas in the second and third ones the lanthanum oxide was partially substituted by lanthanum sulfide, keeping the amount of gallium sulfide fix ed. A pulsed magnetic field between 50 and 80 kG was used for the Faraday r otation measurements. The Verdet constant for one of the ternary samples wa s found to be as high as 0.205 min G(-1) cm(-1) at 543 nm, indicating that these chalcogenide glasses are very promising for magneto-optical applicati ons. The data for each sample were fitted using the expected analytical exp ression for the magneto-optical dispersion. Measurements of the refractive index of the glasses at 632.8 nm are also reported. Data on the magneto-opt ical properties of two high Verdet constant, heavy-metal oxide diamagnetic glasses are also included for comparison. (C) 1999 Society of Photo-Optical Instrumentation Engineers. [S0091-3286(99)00102-6].