Smart tunable 'filter' that offers faster internet experience

Washington: As people look for faster internet experience globally, a team of Canadian researchers has designed a tunable filter that can provide the low-cost flexibility needed for the next generation of high-speed optical networks.

The device's performance is comparable to the best available systems but at a fraction of the size and cost.

The filter's tuning span, which is a measure of how well the device can adjust to fluctuating data demands, is the widest ever demonstrated on a silicon chip.

Additionally, the device has an unlimited free-spectral range, meaning it can operate over any range of frequencies.

According to researchers, the path toward a faster internet has been hindered by energy consumption and cost per optical component.

"Compared to traditional networks, the flexible networks higher data volumes per optical carrier and throughout the entire spectrum," said Wei Shi, assistant professor at Université Laval in Quebec in Canada.

The new filter should save both money and energy because it can be readily integrated onto a photonic chip, he added.

“The most exciting aspect is that these record-breaking results were achieved on the silicon photonic platform," Shi noted.

This indicates that the filter can be readily integrated with other well developed components for a novel integrated system.

The optical spectrum is a limited resource -- as internet traffic has increased dramatically, bandwidth has become more precious.

To maximise the power and cost efficiency of communication, optical networks must be able to flexibly allocate bandwidth, giving each customer only what they need at any given time.

The tunable filter that Shi and his colleagues designed and tested has a tuning span of 670 GHz, much greater than the approximately 100 GHz span other silicon-based filters have achieved.

The researchers believe that with further modification their device's tuning span can be even further extended, to one THz.

Going forward, the researchers plan to integrate the tunable filter with other components on the same chip to test chip-scale flexible optical networking.

The paper appeared in the journal Optics Letters.