Sumitomo is now shipping test samples of optical Thunderbolt cables, which were also used in demonstrations at Intel's booth during the NAB show last week in Las Vegas. The Sumitomo optical cables will enable longer cable runs than the current Thunderbolt copper cables, an Intel spokesman said.

Thunderbolt is a high-speed connector technology that shuttles data between computers and peripherals. The first ports were introduced in Apple's Mac computers in February last year, and current cables are based on copper because of the high cost of fiber optics.

Thunderbolt was co-developed by Apple and Intel and offers data transfer speeds of up to 10 Gbps (gigabits per second), making it a faster alternative to USB 3.0. A full-length, high-definition movie can be transferred from an external storage device to a laptop in less than 30 seconds.

Existing Thunderbolt ports on Macs will be compatible with optical cables. Users can buy existing Thunderbolt products and switch from copper to optical cables without any changes in computers or peripherals.

Intel originally envisioned Thunderbolt as a connector in which pulses of light could be used to transfer data. Last year it said it was getting sufficient throughput with copper, but that optical cables would become available in the future. PC makers like Lenovo, Asus and Acer will offer Thunderbolt ports in Windows laptops later this year.