FIR quantum cascade lasers at λ>20 μm and THz emitters at λ=80 μm

Quantum cascade lasers operating at View the MathML source wavelength are reported. Pulsed operation was obtained up to View the MathML source with a peak power of few milliwatts at cryogenic temperatures. Laser action originates from interminiband transitions in “chirped” superlattice active regions. The waveguides are based on surface-plasmon modes confined at a metal–semiconductor interface, but we also report on a View the MathML source wavelength laser based on a double-sided interface-plasmon waveguide. This latter, contrary to the single-sided surface plasmon, is a viable waveguiding solution in the THz range, i.e. at wavelengths between 60 and View the MathML source. Finally, intersubband electroluminescence is reported in a quantum cascade structure based on asymmetric superlattice active regions and designed for emission in the THz range at View the MathML source.