Earlier this month Sumitomo Electric Industries was the first company to receive Thunderbolt certification from Intel, allowing it to start mass productionof optical Thunderbolt cables.
Thunderbolt is a high-speed communications technology that Apple has used in its latest Mac systems to offer fast data transfer, not to mention new ways to expand Mac systems. While quite fast at 20Gbps (10Gbps bidirectional throughput), the sheer speed of the technology has posed a challenge.
When digital devices communicate, signal quality degrades over increased distance, whether via a wired or wireless connection. This can lead to data packets being lost and retransmitted, reducing performance. Thunderbolt's high speed demands correspondingly high performance from its transmission medium, and so Thunderbolt cables made with conventional copper wiring were limited to around 3 meters in length.
To get around this distance limitation, one can use optical interconnects, which have been part of the Thunderbolt specification from the beginning. Optical Thunderbolt cables were originally slated for general release in 2012 but instead were issued only in small quantities. However, in December 2012 Intel certified Sumitomo's development of its optical Thunderbolt cable, allowing it to start mass production of the technology so as to make it available sometime this year.
There is no word yet on the pricing or exact release dates of the new cables, but there are some things to note.
In addition, the current, copper Thunderbolt cables have a 10-watt power connection that can be used to power small devices, but the new optical cables are only for data transfer and can't be used to supply power. A final issue is the connector size; the current cables' connectors are relatively large at around 28mm in length, but the optical connectors will be even larger, at 38mm.
Aside from these differences, the optical cables should be similar to the current Thunderbolt cables.