Harvard researchers create world’s smallest radio reciever from atomic scale defects in a diamond

Image: SEAS

By tech2 News Staff /  19 Dec 2016 , 17:39

Harvard researchers from the Harvard John A. Paulson School of Engineering and Applied Sciences (SEAS) have built the world’s smallest radio receiver, made out of atomic scale defects in pink diamonds. The tiny radio is robust and biocompatible, which means it can be used in all sorts of extreme applications, from a space probe headed to Venus to a pacemaker embedded in a human body.

The radio is based on nitrogen vacancy centres, with one carbon atom placed in a tiny diamond with a nitrogen atom and removing the neighbouring atom. The nitrogen vacancy centres are then powered by a green laser. The electrons in the nitrogen vacancy centre are sensitive to electromagnetic waves, including FM signals. When the electrons in a nitrogen vacancy centre receive radio waves, they convert the radio waves and emit streams of red light. This red light stream can be interpreted with a photodiode, that converts the stream of light into a current, which can be converted to sound and heard on conventional speakers.

An electromagnet placed around the diamond can be used to tune in to a particular radio station. Billions of nitrogen vacancy centers can be used to boost the signal, but the radio works even with a single nitrogen vacancy center, emitting one photon at a time. The nitrogen vacancy centers can convert information into light, which potentially allows such tiny structures to be used in photonics, sensors and quantum computers.

Emergency agencies choose to not enable encryption on their radio communications

Image: Christiaan Colen, Flickr

  11 Oct 2016 , 10:58

Some police and fire departments are bucking a trend to conceal dispatch communications from the public, acknowledging that radio encryption has the potential to backfire and put first responders in danger.

Agencies with digital radio systems have turned off the encryption to their main dispatching channels and others have decided not to turn it on. They say their officers and firefighters may not be heard during emergencies by responders at neighboring departments with radio systems that either don’t have access to their encrypted channels or aren’t advanced enough to have encryption capability.

Officials also say they are addressing concerns from critics who argue encryption decreases police transparency at a time when it is needed, especially in the wake of shootings of unarmed black people by police officers. “The overwhelming opinion of encryption is that it works great for preplanned tactical environments like SWAT teams staging a situation,” said Eddie Reyes, deputy chief of Amtrak police and chairman of the International Association of Chiefs of Police communications and