Abstract
Fast contrast reversal of magnetic domain images with a photo-elastic modulator (PEM) was studied in two ways. A PEM employed with a quarter wave plate works as a polarization rotator and enables domain observation with fast contrast reversal under a pulsed light exposure. The contrast reversal can be done as fast as 10 μs. However, a PEM is driven sinusoidally, hence the domain contrast is modulated resulting in low contrast in its average. When a PEM was employed as a phase compensator with a garnet film polarization rotator, it compensated unwanted contribution of the ellipticity of a specimen and the garnet rotator dynamically. This combination provided not only fast contrast reversal but even higher contrast compared to that of a conventional method involving mechanical rotation of an analyzer. With the latter method, the domain image contrast of 0.82 was derived theoretically and that of 0.76 was obtained experimentally for do-mains of θk=0.19° and χk=0.13°, while it was 0.72 in the conventional mechanical method.
