The term integrated optics was first coined by Miller in 1969,1 as an analogy of light-wave to the electronic integrated circuits. Indeed, the present term used in industry is planar lightwave circuits (PLCs). Since that term was proposed, tremendous progress has been made. Various integrated optical devices have been researched, developed, and deployed in practical optical transmission systems and networks. Extensive surveys have been given over the years,2,3 and even defined and described on the Internet.4,5 Both linear and nonlinear integrated optics6 have been exploited.