Conceptual survey of phase modulation based wavelength registered networks

The implementation of a dense wavelength-division multiplexing (WDM) based wide-area network inevitably involves a large number of semiconductor lasers requiring particular temperature and driving current control. The concept of a novel multiwavelength network that uses only one laser source to generate all the carriers needed for the entire network is investigated. The central idea is to use a stable reference laser to generate two sets of optical carriers as the `carrier supplies´ for all network nodes: one set for signal transmission and the other for signal reception. A promising feature of the proposed network is the wavelength registration, that is, all carrier wavelengths are unambiguously identified. This special feature is of importance for a standard wide-area multiwavelength network. Optical phase modulation is extensively employed in the carrier generation as well as in information delivery. A 40-wavelength network is considered with each wavelength carrying 20 phase-modulated microwave subcarriers, a total throughput of 160 Gbit/s per single-mode fibre is estimated