Wireless Data Could Move 1,000 Times Faster Thanks to Frequency Combs

By Andrew Tarantola on at

Those glorious 4G connections being tested around the country may seem lighting-quick compared to the 3G molasses you're currently used to, but LTE flows about as fast glass in the face of the Terahertz bandwidth that the University of Pittsburgh is studying.

Current radio frequency technologies are limited to operating on the Gigahertz range. However, a team led by physics and chemistry professor Hrvoje Petek has demonstrated a method of transmitting data in a portion of spectrum a magnitude higher — operating between infrared and microwave light. The team was able to devise a frequency comb "that spans a more than 100 terahertz bandwidth by exciting a coherent collective of atomic motions [read: oscillations] in a semiconductor silicon crystal." In fact, in their demo, the team achieved oscillations of 15.6 THz.

A frequency comb results from dividing a single colour of light into equally-sized chunks that can be used in numerous applications — such as data transmission. "The ability to modulate light with such a bandwidth could increase the amount of information carried by more than 1,000 times when compared to the volume carried with today's technologies," Petek said in a statement.

The University of Pittsburgh News describes the team's endeavors as such,

To investigate the optical properties of a silicon crystal, Petek and his team investigated the change in reflectivity after excitation with an intense laser pulse. Following the excitation, the team observed that the amount of reflected light oscillates at 15.6 THz, the highest mechanical frequency of atoms within a silicon lattice. This oscillation caused additional change in the absorption and reflection of light, multiplying the fundamental oscillation frequency by up to seven times to generate the comb of frequencies extending beyond 100 THz. Petek and his team were able to observe the production of such a comb of frequencies from a crystalline solid for the first time.

Granted, this technology is still highly experimental but if it does reach market, users will be able to enjoy fiber-optic speeds — wirelessly. Of course, that's assuming Petek's team hasn't yet figured out how to leverage the coherent oscillation of electrons into petahertz (that's a QUADRILLION hertz) frequencies. [University of Pittsburgh - Pitt Lab of Ultrafast Dynamics via PC Mag]

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