According to this document, the Trent XWB from Rolls Royce has a fan diameter of 3m and a reference rotational speed of 2700 rpm for the low pressure stage, which would result in a blade tip speed of 424.1 m/s or 1526.8 km/h according to this calculator

In case you missed it in the article, the transfer speeds are mentioned just two paragraphs prior to the one you cited:

Over the next three to four years, Kazansky said, SPhotonix aims to improve the data transfer speed of its technology from a write time of 4 megabytes per second (MBps) and read time of 30 MBps to a read/write speed of 500 MBps, which would be competitive with archival tape backup systems.