Various wavelength conversion (WC) techniques are introduced, and two are chosen to be used in all optical transparent networks. These are four wave mixing (FWM) and difference frequency generation (DFG).

• 该文首先简单介绍各种波长变换技术；对比它们的优缺点；选出两种能用于未来全光透明网络中的波长变换技术:四波混频波长变换技术和差频波长变换技术.