Quantum cascade laser with integrated third order resonant optical nonlinearity

This paper presents a quantum cascade (QC) laser having an active region designed for both pump radiation emission and third order nonlinear emission. This design produces third harmonic generation from an InGaAs/AlInAs QC laser based on a three-well diagonal transition active region with an integrated third-order nonlinear oscillator. This design ensures efficient coupling of pump photon energy hv to the intersubband transitions of the nonlinear element and maximal overlap of interacting waveguide modes in the nonlinear active region. The problem of pump absorption is solved since the pump is generated in the nonlinear medium.