The terahertz quantum cascade laser on its mounting. Credit: University of Leeds Lasers that switch on and off billions of times per second are the backbone of optical communications networks, but ...

Lasers work by emitting light that is “coherent” in that it doesn’t spread out in a disorganized way like light from most sources does. This makes extremely focused beams possible that can do things ...

Wave frequency is a critical parameter for applications ranging from human hearing, acoustic non-reciprocity, medical imaging to quantum of energy in matter. Frequency alteration holds the promise of ...