Magneto-optic astrometer for measurement of magneto-thin-film memories
01 January 1966
The apparatus involves the use of the Kerr magneto-optic effect. Factors influencing the signal to noise ratio are considered i.e. the reflection coefficient, the light source, and the band-width of the amplifier. Variations of the magneto-optic component of a light spot reflected from a surface are transformed into voltage variations. These, after amplification, modulate the intensity of an oscilloscope spot. Horizontal and vertical deflections of the spot are proportional to magnetic field parallel to the hard axis and easy axis respectively. Thus the critical curve is directly plotted. The dimension of the light spot is 0.4 by 0.6 millimeters.