Highly oriented a-axis BaTiO3 thin films were grown by pulsed laser de
position on (001) MgO substrates. The full width at half-maximum of th
e (200) BaTiO3 rocking curve was as narrow as 0.6 degrees. A large hys
teretic quadratic electro-optic effect was observed in a transverse ge
ometry at 6328 Angstrom. A birefringence shift up to 3X10(-3) was meas
ured at an applied de electric field of 1 kV/mm. It was found that las
er repetition rate plays an important role on the surface morphology o
f the deposited films. (C) 1995 American Institute of Physics.