Abstract: A wavelength division multiplexer is provided by the present invention, which implements the wavelength division multiplexing and de-multiplexing of the optical signals in the basic and upgrade bands by reasonably arranging the filters and selecting the spectral properties of the filters, so that the existing time division multiplexing passive optical network (TDM-PON) can transmit the next generation passive optical network (NG-PON) simultaneously and the existing TDM-PON can be smoothly upgraded to the NG-PON, meanwhile, it provides the deployed TDM-PON with the subsequent network compatibility. The wavelength division multiplexer provided in the present invention can meet the high isolation requirement of the optical signals in working band with low cost, and takes both the isolation requirement and the optical network insertion loss requirement into account, thus it has high reliability, is easy to use and for system upgrade.

Abstract: A wavelength division and time division hybrid multiplexing passive optical network system, terminals and a signal transmission method are disclosed in the present invention. The system comprises: a plurality of optical modules at the optical line terminal side connecting to an office all-optical wavelength conversion unit, the all-optical wavelength conversion unit connecting with a subscriber all-optical wavelength conversion unit via a fiber, and the subscriber all-optical wavelength conversion unit connecting with a plurality of optical couplers, and each optical couplers connecting with a plurality of optical network units respectively; the present invention facilitates full use of the existing source of access network and ensures a smooth transition from the time division multiplexing passive optical network to the optical access network of the next generation without changing the structure of the current time division passive optical network.