ASYMPTOTIC-BEHAVIOR OF THE BOUNDARY-VALUE PROBLEM OF 4-WAVE-MIXING INPHOTOREFRACTIVE MEDIA

Solutions to the four-wave mixing problem asymptotically approach a sp atial steady state over large interaction distances. In this limit, in tensities of the two-point boundary value problem may be found from so lutions to quadratic equations. The different limiting behavior exhibi ted for positive and negative gain has important implications for appl ications in which linearity of system response is important. In the re gime studied, positive gain leads quickly to maximally depleted pumps with increasing input signal. For negative gain, such depletion does n ot occur until higher signal levels are reached.