Technology and applications of the integrated acousto-optic filter

Technology of the integrated acousto-optic filter has advanced remarkably over the last several years, leading to polarization diversity WDM switches, filters and switches with controllable passband shape, and AOTFs with internal gain. Along with these technological developments, AOTFs have advanced in many important applications areas including WDM optical communication systems, gain equalization of optical amplifier chains, intracavity tuning of lasers and optical spectrometry. The evolution of the AOTF is reviewed and several applications presented.