With linear optical components to manipulate quantum states of optical fields, the quantum entanglement control and quantum communication can be implemented remotely.By analyzing optical splitter and its use of coherent states, it was found that when the initial state was a direct product of two partially entangled coherent states; another two modes would collapse to a new entangled state using optical splitter and photon-detectors on two modes. Based on this feature, the scheme on entanglement concentration was presented. In this scheme, the two partially entangled coherent states were utilized as the quantum channel, when zero photon and odd photons were detected in two modes separately, and another two modes would collapse to the maximum entangled state, thereby completing the process of the entanglement concentration. It was proved that, no matter how small the initial entanglement is, to distill some maximally entangled states from partially entangled pure states is possible.