US Patent-Quantum cascade external cavity laser with metasurfaces

United States Patent 9728930
Inventors:
Williams, Benjamin Stanford (Los Angeles, CA, US) 
Xu, Luyao (Los Angeles, CA, US) 
Chen, Daguan (Los Angeles, CA, US)

http://www.freepatentsonline.com/9728930.html

A metasurface reflector for quantum cascade lasing is disclosed. The metasurface reflector uses an array of subcavities disposed on a substrate and spaced with a sub-wavelength period. Each of the subcavities includes a layer of quantum-cascade-laser-active material sandwiched between two metallic layers. The array of subcavities reflect an incident light of a resonant frequency with amplification. When used with an output coupler, a quantum cascade laser beam can be generated.