Science Daily February 11, 2020
To be able to send data at increased speeds, the lasers need to be modulated very rapidly: switching on and off or pulsing around 100 billion times every second. Instead of using external electronics, researchers in the UK used acoustic waves to vibrate the quantum wells inside the quantum cascade laser. The acoustic waves were generated by the impact of a pulse from another laser onto an aluminium film that caused the film to expand and contract, sending a mechanical wave through the quantum cascade laser. They were able to control the light output by a few percent. They believe that with further refinement, they will be able to develop a new mechanism for complete control of the photon emissions from the laser, and perhaps even integrate structures generating sound with the terahertz laser, so that no external sound source is needed…read more. Open Access TECHNICAL ARTICLE
Experimental arrangement and QCL device structure and characteristics. Credit: Nature Communications volume 11, Article number: 835 (2020)