We propose and describe a new configuration for splitting and combining operations of high-speed amplitude-modulated optical signals between the two interacting beams by using two-wave mixing in photorefractive Cu-doped (K0.5 Na0.5)0.2 (Sr0.61 Ba0.39)0.9 Nb2O6 (Cu-KNSBN) crystal. These operations are simultaneously achieved by changing the intensity ratio of the two incident beams. We also apply this scheme to a photorefractive pulse shaping in the time domain that consists of two amplitude-modulated beams that are coupled automatically through two-beam interactions in the crystal. Some preliminary experimental results are presented and discussed.