SAW PROPERTIES OF LI2B4O7 CRYSTALS AND THEIR APPLICATIONS TO ACOUSTOOPTIC WAVE-GUIDE MODULATORS

Theoretical and experimental results have shown the potential usefulne ss of Li2B4O7 crystals for leaky SAW and acousto-optic applications. T he shear leaky SAW has excited at (45 degrees, 90 degrees, 70 degrees) , whose SAW properties are v(p) of 3680m/s, k(2) of 2.3% and TCD of 0. Further, k(2) of the Rayleigh SAW was zero at this cut substrate, whi ch gives no spurious response for the temperature compensated shear le aky SAW. The longitudinal leaky SAW with the fast v(p) of 6825m/s has been also observed at the (0 degrees, 45 degrees, 90 degrees). Several amorphous thin films were successfully fabricated on the (110) LBO su bstrates by sputtering. Among them, the berate glass film has been a s uitable material for acousto-optic applications because it has lower v elocity and relatively larger index than those of LBO substrates.