High−performance acousto−optic guided−light−beam device using two tilting surface acoustic waves

Abstract

An acousto−optic guided−light−beam device utilizing two surface acoustic wave interdigital transducers, which are staggered in their center frequency and tilted in their propagation direction, on an essentially single−mode optical guiding layer of a Y−cut LiNbO3 substrate has been shown to be capable of providing a very wide bandwidth. Deatiled measurements on the diffraction efficiency and the deflection angle of the light beam versus the frequency of the driving signal, usign a 6328−Å He−Ne laser light, are presented. The measured −3 dB bandwidth of the device is close to 200 MHz, which is more than an order of magnitude larger than that obtained in previous devices, with the measured electric driving power of 200 mW at 50% diffraction efficiency. The new device configuration introduced here should be very useful for wide−band applications such as a guided−wave acousto−optic rf spectrum analyzer and high−speed multiport switches for fiber/integrated optics.