Control and application of domain wall motion in gadolinium molybdate

Sideways motion of ferroelectric-ferroelastic domain walls in gadolinium and terbium molybdates can be produced with electric fields as low as 200 volts/cm, in relatively defect-free crystals. Crystal mounting and electroding techniques are described that suppress intersections of perpendicular walls, a primary source of crystal failure. Using these techniques, a GMO crystal has been switched successfully over 109 times with no change in physical properties. Polarized light transmitted along the r-axis through a GMO domain wall can be distinguished from light transmitted through surrounding regions of the crystal by spatial and/or polarization filtering. Light exiting the wall can be imaged at 1:1 magnification as a straight, bright line 8-10 microns wide on a dark background. This line can be translated sideways at 250 cm/sec without tilting or bending. Preliminary performance data is given for a prototype GMO-based moving fine line source.