The wavelength division multiplexing (WDM) technology has led to a tremendous amount of commercial and research interest in WDM-based networks. The emergence of WDM networking components led people to design and deploy WDM based networks. Such networks take advantage of the flexibility and configurability of components. In principle the optical time division multiplexing (OTDM) and Optical code division multiplexing (OCDM) can be exploiting to utilize the fiber bandwidth. But presently these technologies are in developing stage. In this paper the recent developments in WDM based optical networks are presented.