The relentless push of Moore's Law has allowed data rates to soar, Internet traffic to swell, and wired and wireless technology to cover continents. Increasingly, we all expect fast, free-flowing bandwidth whenever and wherever we connect with the world. Within the next decade, the circuitry embodied by a rack of today's servers, able to churn through billions of bits of data per second and handle all the data-processing needs of a small company, will fit neatly on a single silicon chip half the size of a postage stamp.

But there's a problem. As newer, faster microprocessors roll out, the copper connections that feed those processors within computers and servers will prove inadequate to handle the crushing tides of data. At data rates approaching 10 billion bits per second, microscopic imperfections in the copper or irregularities in a printed-circuit board begin to weaken and distort the signals—even traveling distances as short as 50 centimeters can be a problem. New board materials and new techniques could provide some additional performance gains, but only at increased cost.

Here's a better way: replace the copper with optical fiber and the electrons with photons.

That's the promise of silicon photonics: affordable optical communications for everything. It will let manufacturers build optical components using the same semiconductor equipment and methods they use now for ordinary integrated circuits, thereby dramatically lowering the cost of photonics. Meanwhile, the performance gains will be significant: integrated onto a silicon chip, an optical transceiver could send and receive data at 10 billion or even 100 billion bits per second.

Source : IEEE Spectrum