All-optical wavelength reservation for flexible spectrum networks using amplifier saturation and VCSEL injection

Abstract

Advanced metro-access WDM optical fibre telecommunication networks employ integrated wavelength switching nodes to provide efficient, flexible wavelength allocation along the link. Recent developments, together with the increase in bandwidth intense applications, have sparked great interest in flexible, grid-like optical network systems. Flexible spectrum optical network systems with non-static channel bandwidth, wavelength allocation, switching and routing permit the optimum distribution of data with variable rates and modulation formats. This paper describes a unique technique for all-optical wavelength reservation at a forwarding flex spectrum node. The outgoing signal is locked to the incoming signal at the node, thereby guaranteeing automatic wavelength reservation and allocation. A saturated EDFA is used to erase data from the incoming signal, which is then used to lock the wavelength of the forwarding node through VCSEL injection. The EDFA is shown to reduce the extinction ratio of the incoming signal from 7.3 dB to less than 1 dB (560 mdB). We show automatic wavelength reservation over 1.68 nm within the C-band, with 25.5 km transmission over G. 655 single mode fibre. Considering 50 GHz per-channel bandwidth allocations, this technique translates to 4-channel operation in a typical metro-access type configuration.