Intel has a record breaking silicon-based “Avalanche Photodetector” with a gain-bandwidth product of 340GHz. This is the first time a silicon photonic device beats its equivalent made from traditional optoelectronic materials. [From Intel Teleconference Dec 4, 2008 given by Mario Paniccia.]
Avalanche Photodetectors detect light and additionally amplify signals by multiplying electrons. The amplification provided by APDs makes them more sensitive. This sensitivity can be used to reduce power requirements or extend operating distance.
Avalanche photodetectors are found inside bulky optical networking equipment and currently cost $200 to $300 dollars apiece. If these detectors could be made out of silicon, Paniccia says they could cost less than $10. Higher bandwidth at lower cost.
The new detector is not yet ready to appear in products. There is still work to do in reducing dark current. Dark current is stray current that leaks from the device even when it's not absorbing photons. Intel expects commercial silicon photodetectors in the next couple of years. All of the silicon photonic devices can be made in regular Intel fabs.
Intel researchers see integrating intels processors with an optical networking chip in a hybrid package of the two chips initially. Perhaps in 5 years later or so there would be integration of the chips.