Intel has given details of the research it is doing in order to overcome the limitation of copper interconnects between processors.

Speaking at the Intel Developer's Forum in San Francisco, Pat Gelsinger, chief technology officer, described how Intel is looking into optical chip-to-chip connections for when copper reaches its physical limits.

The optical project is part of its 'Research without Walls' initiative aimed at restructuring its research programme.

Working with the chip company on the task is the University of California at Berkeley.

In a small lab near the university, researchers from both organisations will work together to look into using optical connections for future computers.

This is one of a number of 'lab-lets' Intel has set up in combination with various universities and research institutes, Gelsinger added.

Intel hopes to gain from the research by getting a licence on any intellectual property that results from the work.

Gelsinger said that "silicon would be the preferred medium" although it has been almost impossible to generate any ight from the material. He added that indium phosphide mixed with silicon would be a good alternative, as it has better light emitting properties.

Another 'lab-let' is currently working on terahertz transistors, as reported by vnunet.com last year.

These transistors measure just 0.015-microns, a sixth of the size of the next-generation Pentium chips.

Gelsinger added that the transistors would "require a very high K dielectric to form the gate" and said that prototypes would be available by 2007.