have shown silicon lasers and waveguides designed to facilitate optical communications on future CMOS chips. And last fall, Luxtera Inc. (Carlsbad, Calif.) announced it was sampling the first CMOS chip designed to plug-and-play with existing optical networks.
Now Lightwire Inc. (Allentown, Pa.) has also announced it is sampling a CMOS photonics chip aimed at replacing existing 220 meter line-replaceable modules (LRM) with small form factor pluggable modules based on silicon.
"Luxtera and Lightwire are answering different questions about what silicon can be used for in optical networks," said Liu. "Luxtera is answering the question of whether both electrical and optical components can be integrated onto the same chip, and Lightwire is answering the question of whether they should be."
Luxtera's single chip device integrates both an LRM's electrical transceivers and the optical waveguides onto a CMOS chip; Lightwire has divided the labor between a 65-nm chip for electrical processing and a 130-nm chip dedicated exclusively to the optical functions.
"By using two chips instead of one, we think we can move more quickly to multichannel 40 gigabit and 100 gigabit versions," said Lightwire founder and chief technology officer Kal Shastri. "Our existing 130-nanometer optical chip design will also work at 40 gigabits, so we just have to refine the electrical chip."
So far, Lightwire's strategy appears to be working since the company claims its single channel chip consumes only 400 milliwatts, compared to 500 milliwatts per channel for Luxtera's four-channel device. When Lightwire moves to a four-channel device, it claims power consumption will be half that of Luxtera's--1 watt compared to 2.