Microsoft and Facebook test 400G on trans-Atlantic cable

摘要

A field demonstration conducted by Acacia Communications, in collaboration with Microsoft and Facebook, achieved the first 400G single carrier DWDM transmission over the 6,600 km Marea submarine cable between Virginia Beach, Virginia and Bilbao, Spain. The transmission employed Acacia's AC1200 coherent module, which is powered by its Pico digital signal processor. Utilizing Acacia's patented Fractional QAM modulation, the field demonstration achieved 400G transmission using approximately 4 bits/symbol, with a baud rate of nearly 70Gbaud. Additionally, modulation formats greater than 4 bits/symbol were utilized to achieve a spectral efficiency of 6.41 b/s/Hz on the same 6,600 km cable.