In this paper, an all optical wavelength multicasting service in AWG-based WDM PON is introduced. Two novel architectures of remote node supporting all optical wavelength multicasting functionality are proposed. The interesting characteristic of this function is that, different from the current PON systems which broadcast the signals to all the receivers, here, multicasting signals will be delivered only to selected users. Therefore, it reduces the waste of fibre bandwidth of the users who do not join the multicast group. Moreover, it restricts the information delivery only to the registered receivers, which enables the truly secured multicasting service in access network. Besides, system control and provisioning concern are addressed as well. Comparisons and analysis of two novel architectures are presented and both advantages and shortages of two designs are pointed out.