Nonlinear Optics: Materials and Devices 87 They convened to discuss the Jr They convened to discuss the state of the art in two phase flow and heat transfer and formulated recommendations for future research directions Til stammen Tuatha De Danann it is becoming increasingly unrealistic to expect to cover the different facets and trends of this field in the lectures or proceed ings of a summer school However much of the current progress and interest in this field springs to a large extent from the promise and expectation that highly performing all optical devices that exploit and operate on the principles of nonlinear optics will constitute an important branch of future technology and will provide new alternatives in information processing and transmission