Extending a DWDM optical network test system to 10 Gbps ×4

In 2009 IMS3TW we presented a “Development Platform” for prototyping new multi-GHz ATE [1,2,3]. At that time, a complete multi-channel 2.5 Gbps (per channel) test system was shown as the first application of the Development Platform. In this configuration, 9 transmitter channels (TX) and 9 receivers (RX) were used to test an all-optical Dense Wavelength Division Multiplexing (DWDM) switching network. Additionally, several experimental modules were shown that supported signals in the 10 to 20 Gbps range. In this present paper we incorporate elements from these prototypes into new, full-feature test modules targeting applications running at 2.5 to 20 Gbps (per channel). Specifically, we are extending the optical test system to handle burst-mode DWDM packets with each wavelength running at 10 Gbps (4-times that of the original system). Using 8 TX channels we achieve an aggregate data rate of 80 Gbps within the burst-mode packet (similar for RX). Alternatively, some modules can be used to double the channel-count (up to 18), while operating at the lower 2.5 Gbps rate. The new modules include interesting testability features such as: (1) provisions to support “loopback” testing of DUT output-to-inputs, (2) DC electrical tests, (3) 2-to-1 multiplexing up to 20 Gbps, (4) ATE loopback self-test, and (5) ATE calibration paths. We have recently built multiple Development Platforms that can be operated independently or optionally synchronized using very low-jitter (~1ps RMS) clock distribution paths.