As fiber-optic telecommunications networks have strained to keep up with consumer demands for increased digital audio and video capacity over the past couple of decades, researchers with the Institute of Ultrafast Spectroscopy and Lasers (IUSL) at the City College of New York believe they may have stumbled upon a discovery that could make everyone in the industry sigh a little breath of a relief. By mapping spiraling light in optical fibers with a model called the Higher Order Poincare Sphere (HOPS), the team, led by graduate student Giovanni Milione and Professor Robert Alfano, may have unlocked the secret to tapping into currently unused data channels.
Milione says: “People now can detect [light in] the ground channel, but this gives us a way to detect and measure a higher number of channels. With such heavy traffic funneled through a single channel, there is great interest in exploiting others that can be occupied by complex forms of light.”
The Poincare Sphere (the plain, old, non-pretentious Poincare Sphere and not the fancy, shmancy, elitist Higher Order Poincare Sphere) has been used in the past to map simple displays of light. It visualizes peaks and troughs like — as the team describes — “waves on the ocean,” and intersects with the sphere as latitude and longitude on a globe. A more complex visualization (which is where the Higher Order Poincare Sphere comes in) requires seeing other properties inherent in light that aren’t as easy to observe. Imagine forces such as spin and orbital factors along with tornado-like twists with vector beams and vortices.
Alfano elaborates: “This kind of organization on the higher level Poincare Sphere could clear the path to a number of novel physics and engineering efforts such as quantum computing and optical transitions; could greatly expand the sensitivity of spectroscopy and the complexity of computer cryptography; and might further push the boundaries [of] what can be ‘seen.'”
The team’s work was published in the July 25th edition of Physical Review Letters, and Mr. Milione will be presenting it at the Optical Society of America’s Frontiers in Optics 2011 conference on October 16th – 20th in San Jose, California.