An integrated-optic Fourier processor using an acoustooptic deflector and Fresnel lenses in As2S3waveguide

An integrated-optic Fourier processor consisting of an acoustooptic (AO) deflector and graded-index Fresnel lenses in an As2S3waveguide on a SiO2/Si substrate is proposed and the prototype device is demonstrated. For the interdigital transducer (IDT) for surface acoustic wave excitation, a two-stage array of uniform-period IDT and a chirped IDT using a ZnO piezoelectric film are adopted. High efficielicy and low drive power, as well as wide bandwidth of one octave in the device with a chirped IDT, have been obtained and the Fourier transformation function has been confirmed.