A wide-band acoustooptic TE-TM mode converter using a doubly confined structure

Bandwidth limitations of collinear acoustooptic TE-TM mode converters have been overcome by a method in which the optical and surface acoustic waves have been interacted in a doubly confined waveguide structure. A 5 percent bandwidth centered at 550 MHz and a conversion efficiency of 50 percent at a total acoustic input power of less than 1 mW have been obtained with -cut LiNbO3. It is found that the power transfer efficiency does not degrade significantly when the phase mismatch increases.