Recently, scientists made a breakthrough in the control of terahertz quantum cascade lasers, which could cause the transmission of information at the speed of 100 gigabits per second, approximately one thousand times faster than a quick Ethernet operating at 100 megabits a second.
They have applications in the area of spectroscopy, where they’re used in chemical analysis.
The lasers could also eventually offer ultra-fast, short-hop wireless connections where large datasets need to be moved across hospital campuses or between research centres on universities, or in satellite communications.
To have the ability to send data at these increased speeds, the lasers will need to be modulated very quickly: switching off and on or pulsing around 100 billion times each second.
Rather than using external electronic equipment, the groups of researchers in Leeds and Nottingham Universities used acoustic waves to vibrate the quantum wells within the quantum cascade laser.
The acoustic waves were created by the effects of a pulse from a different laser onto an aluminium film. This caused the film to expand and contract, delivering a mechanical wave throughout the quantum cascade laser.