Some of the researchers at the School of UCLA Henry Engineering and the applied Sciences have then identified a new semiconductor laser that will be operating at the terahertz frequencies . Terahertz waves are basically used to take part in the analyzing of the clothing, semiconductors, plastics and other art materials to be examined they have a chemical sealing and identification.
Just to make it possible an external cavity was maintained and the ULCA researchers have taken a reflectarray metasurfcae mirror. it doesn’t ‘see’ the cavities, but is reflected as if it were being reflected from a simple, flat mirror. Unlike a mirror however, the device amplifies the terahertz waves as well as reflecting them.