All-optical programmable time-slot-interchanger using optical-label switching with tunable wavelength conversion and N by N arrayed waveguide grating routers

Optical packet switching can seamlessly integrate data networking and optical networking [1]. Recent advances in optical technology make it possible to create systems with the capability to do switching in multiple domains (time, space and wavelength). Time-slot-interchange (TSI) is a form of network switching in time domain. Previous experimental TSI systems involve semiconductor laser amplifier switches and fiber delay lines [2] or Fiber Bragg Grating (FBG) [3]. Both methods limit the scalability. The N-channel TSI system in this paper has the same basic structure as the photonic packet buffer proposed in [4]. The system uses optical label switching with tunable wavelength conversion and Arrayed Waveguide Grating Routers (AWGRs). Fig.1 (a) shows the architecture. A series of packets come on each of the N input ports. The extracted header (or “optical label”) content of the packet induces the switch controller to switch the data payload onto different wavelength via the Tunable Wavelength Converters (T-WC). Thus the AWGRs will guide the payloads with different wavelengths through different delays. Compared with other TSI architectures, this architecture provides decent scalability (N can be large), high power efficiency (input does not split) and programmability (switch controller is re-programmable).