Wide-band guided-wave acoustooptic Bragg diffraction and devices using multiple tilted surface acoustic waves

Guided-wave acoustooptic Bragg diffraction from a single surface acoustic wave (SAW) and from two tilted SAW's has been analyzed to establish the design parameters of the related devices. Design and performance figures of the devices involving three and four tilted SAW's in single-mode Y-cut LiNbO3out-diffused waveguides are described in detail. Device bandwidth of up to 358 MHz, an optical throughput coupling efficiency of up to 25 percent, and very good optical beam quality have been realized. A bandwidth of 358 MHz enables the device to deflect a light beam of 1-cm aperture into 1000 resolvable spot diameters with a random-access switching time of 2.8 µs. A total electric drive power of 220 mW was required to diffract 50 percent of the incident light power for the unit with 245-MHz bandwidth. The development of this wide-band technique has paved the way for using such guided-wave acoustooptic devices in a number of applications in addition to those common to bulk-type acoustooptic devices.