THz laser based on quasi-periodic AlGaAs superlattices

The use of quasi-periodic AlGaAs superlattices as an active element of a quantum cascade laser of terahertz range is proposed and theoretically investigated. A multi-colour emission, having from three to six peaks of optical gain, is found in Fibonacci, Thue–Morse, and figurate superlattices in electric fields of intensity F = 11 – 13 kV cm^-1 in the frequency range f = 2 – 4 THz. The peaks depend linearly on the electric field, retain the height of 20 cm^-1, and strongly depend on the thickness of the AlGaAslayers.