Integrated acoustically-tuned optical filters for filtering and switching applications

The recent evolution of integrated acoustooptic filters, which has been driven by the successive integration of ever more sophisticated guided-wave structures on a single X-cut lithium niobate substrate, is reviewed. The most highly integrated device to date is a versatile low-power, polarization-independent four-port wavelength-division switch. Acoustooptic filter applications are discussed, including laser tuning, spectroscopy, frequency shifting, and wavelength filters and switches for wavelength multiplexing. >