Wavelength optical/electronic encoding module for ATM optical-switching

We present a novel wavelength-encoding module, suitable for high-speed wavelength switching in wavelength-division multiplexing (WDM) networks. This module includes a tunable DBR laser and an original GaAs IC-driver, which is a full custom 0.5-μm gate-length P-HEMT IC. With fast switching time (300 ps), low power consumption (1.4 W), and small dimensions, this tunable-driver advantageously replaces the conventional electronics. Switching over four wavelength-modes has been demonstrated with parasitic wavelength-drifts lower than 0.02 nm, and switching times are mainly laser dependent. Implementation of the module inside a 4×4 ATM switching-matrix demonstrator working at 2.5 Gbit/s shows no degradation of the EER.